NEET Biology

NEET Biology Multiple Choice Questions – Biodiversity And Conservation

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NEET Biology For Biodiversity And Conservation Multiple Choice Questions

Question 1. Out of more than 1.5 million known species, insects are of the total animals.

  1. 70%
  2. 25%
  3. 50%
  4. 75%

Answer. 1. 70%

Question 2. Which is not true regarding genetic diversity?

  1. It enables a population to adapt to its environment.
  2. It is also the basis of speciation.
  3. Ecotype formation depends upon it.
  4. Higher diversity increases uniformity.

Answer. 4. Higher diversity increases uniformity.

Question 3. Regional diversity is also called

  1. Alpha diversity
  2. Beta diversity
  3. Gamma diversity
  4. Ecosystem diversity

Answer. 3. Gamma diversity

Question 4. Which of the following biogeographical regions in India has the highest coverage?

  1. Deccan Peninsula
  2. NE Himalayas
  3. Western Ghats
  4. Gangetic Plain

Answer. 1. Deccan Peninsula

Question 5. Which is not a reason of maximum diversity in tropics?

  1. Higher pest pressure
  2. Evolutionary older zone
  3. High rate of out-crossing
  4. Greater environmental variations

Answer. 4. Greater environmental variations

Question 6. Threats to biodiversity come from

  1. Habitat loss
  2. Over exploitation
  3. Intensive agriculture
  4. All of the above

Answer. 4. All of the above

Question 7. The disappearance of cheetah from India and its existence in other part of the world is an example of

  1. Extinction
  2. Extirpation
  3. Background extinction
  4. Anthropogenic extinction

Answer. 2. Extirpation

Question 8. Silent Valley of Kerala is being preserved because it has

  1. Rare plants and animals
  2. Only natural forest of India
  3. Costly timber plants
  4. Recreational value

Answer. 1. Rare plants and animals

Question 9. Anti-forest conservation is

  1. Selective felling
  2. Control of forest fire
  3. Large-scale clearing
  4. Ban on hunting

Answer. 1. Selective felling

Question 10. The species which are likely to be in the danger of extinction in the near future if the factors threatening their extinction continue are known as

  1. Threatened species
  2. Rare species
  3. Vulnerable species
  4. Endangered species

Answer. 3. Vulnerable species

Question 11. In India, forests constitute about

  1. 19.4% of the land area
  2. 33.7% of the land area
  3. 33% of the land area
  4. 67% of the land area

Answer. 1. 19.4% of the land area

Question 12. Bamboos are abundant in

  1. Dry moist deciduous tropical forests
  2. Coniferous forests
  3. Alpine forests
  4. Rain forests

Answer. 1. Dry moist deciduous tropical forests

Question 13. 85% of world’s food comes from

  1. < 20 plant species
  2. < 50 plant species
  3. < 5 plant species
  4. < 100 plant species

Answer. 1. < 20 plant species

Question 14. A population characteristic of a species susceptible to extinction is

  1. Low trophic level in food chain
  2. Inability to switch over to alternate food source
  3. Wide range of distribution
  4. High biotic potential

Answer. 2. Inability to switch over to alternate food source

Question 15. The number of red list categories prepared by WCU (IUCN) is

  1. 6
  2. 7
  3. 8
  4. 9

Answer. 3. 8

Question 16. According to IUCN, when a taxon is facing an extremely high risk of extinction in the immediate future, it is

  1. Extinct in the wild
  2. Endangered
  3. Critically endangered
  4. Vulnerable

Answer. 3. Critically endangered

Question 17. Projected areas are examples of

  1. In situ conservation
  2. Ex situ conservation
  3. Cryopreservation
  4. Green houses

Answer. 1. In situ conservation

Question 18. The zone of biosphere reserve where no human activity is permitted is known as

  1. Buffer zone
  2. Core zone
  3. Manipulation zone
  4. None of these

Answer. 2. Core zone

Question 19. Floods can be prevented by

  1. Making the soil less sloppy
  2. Removing forests
  3. Removing soil cover
  4. Planting trees on slopes and building dams

Answer. 4. Planting trees on slopes and building dams

Question 20. Indian rhinoceros is the most important protected species in

  1. Gir National Park
  2. Bandipur National Park
  3. Corbett National Park
  4. Kaziranga National Park

Answer. 4. Kaziranga National Park

Question 21. The Government of India has provided private ownership rights in

  1. A national park
  2. A sanctuary
  3. A biosphere reserve
  4. Zoo

Answer. 2. A sanctuary

Question 22. Wild populations of plants and animals and traditional life styles of tribals are protected in

  1. Biosphere reserve
  2. Sanctuary
  3. National park
  4. None of these

Answer. 1. Biosphere reserve

Question 23. Man-made mass extinction of species represents a severe depletion of biodiversity called

  1. Mass extinction
  2. Natural extinction
  3. Anthropogenic extinction
  4. Human extinction

Answer. 3. Anthropogenic extinction

Question 24. Which of the following exotic species has become menace to many water bodies in India?

  1. Lantana camara
  2. Eichhomia crassipes
  3. Parthenium hysterophorus
  4. Eupatorium odoratum

Answer. 2. Eichhomia crassipes

Question 25. Which is not a criterion used for determining hot spots?

  1. Number of endemic species
  2. Degree of habitat destruction
  3. Haying traditional strategy for protection of biodiversity
  4. Degree of exploitation

Answer. 3. Haying traditional strategy for protection of biodiversity

Question 26. Which anticancerous botano-chemical is obtained from a gymnosperm?

  1. Ephedrine
  2. Strychnine
  3. Taxol
  4. Reserpine

Answer. 3. Taxol

Question 27. Which potato species is nematode resistant?

  1. Solanum spegazzini
  2. S. demissum
  3. S. acaule
  4. S. stoloniferum

Answer. 1. Solanum spegazzini

Question 28. A few years ago, the brown plant hopper (Nilaparvata lunges) threatened the cultivation of

  1. Wheat
  2. Rice
  3. Maize
  4. Millets

Answer. 2. Rice

Question 29. An important international effort or convention for biodiversity conservation is

  1. UNESCO
  2. WWF
  3. IBWL
  4. NBPGR

Answer. 2. WWF

Question 30. Find the odd one out (with respect to weed):

  1. Lantana camara
  2. Eicchornia
  3. Parthenium argentatum
  4. Parthenium hysterophorus

Answer. 3. Parthenium argentatum

Question 31. How many species became extinct in the last 500 years?

  1. 338
  2. 359
  3. 784
  4. 2000

Answer. 3. 784

Question 32. How many hot spots cover India’s high biodiversity regions?

  1. 25
  2. 3
  3. 34
  4. 2

Answer. 2. 3

Question 33. Overexploitation has resulted in the extinction of

  1. Steller’s cow
  2. Lantana
  3. Passenger pigeon
  4. Both (1) and (3)

Answer. 4. Both (1) and (3)

Question 34. Wildlife (protection) Act 1972 includes which of the following objectives?

  1. Setting up and managing sanctuaries and national parks
  2. Restriction and prohibition on hunting animals
  3. Protection of specified plants
  4. All of the above

Answer. 4. All of the above

Question 35. Best way to preserve the wildlife is

  1. To kill the predators
  2. Vaccinize the animals
  3. Optimize the breeding habit
  4. To preserve their natural habitat

Answer. 4. To preserve their natural habitat

Question 36. Wildlife conservation aims at

  1. Maintaining the ecological process
  2. Enriching the wildlife diversity with exotic species
  3. Preventing migration of species
  4. Maintaining the diversity of life

The correct statements are:

  1. (1), (4)
  2. (3), (4)
  3. (1), (2)
  4. (2), (3)

Answer. 1. (1), (4)

Question 37. All forms of life should be conserved because

  1. They will be otherwise lost
  2. They have economic values
  3. They maintain diverse genetic resources
  4. They are important for maintaining balance of nature

Answer. 3. They maintain diverse genetic resources

Question 38. Which of the following types of animals does man chiefly protect?

  1. Week animals
  2. Harmless animals
  3. Those likely to perish
  4. Economically useful animals

Answer. 3. Those likely to perish

Question 39. The national bird of India is

  1. Peacock
  2. The hornbill
  3. Black swan
  4. House sparrow

Answer. 1. Peacock

Question 40. Scientific name of our national bird is

  1. Gallus gallus
  2. Columba livia
  3. Pava cristatus
  4. Corvus splendens

Answer. 3. Pava cristatus

Question 41. The biological name of the domestic cat is

  1. Felis leo
  2. Panthera indica
  3. Panthera domestica
  4. Felis domestica

Answer. 4. Felis domestica

Question 42. The “Sangai” of Manipur is a

  1. Great pied hornbill
  2. Black-necked crane
  3. Brow antlered deer
  4. Retienlated python

Answer. 3. Brow antlered deer

Question 43. Sarus is also known as

  1. Crane
  2. Spotbill
  3. Plovers
  4. Flamingoes

Answer. 1. Crane

Question 44. Black buck is

  1. Cervulus muntiac
  2. Antilope cervicapra
  3. Moschus moschiferus
  4. Boselaphus trogocamelus

Answer. 2. Antilope cervicapra

Question 45. Which among the following is an Indian monkey?

  1. Simia
  2. Gorilla
  3. Macaca
  4. Pongidae
  5. Ramapithecus

Answer. 3. Macaca

Question 46. Number of wildlife is continuously decreasing. What is the main reason for this?

  1. Hunting
  2. Predation
  3. Cutting down forest
  4. Destruction of habitat

Answer. 4. Destruction of habitat

Question 47. Most of the endangered species are victims of

  1. Acid rain
  2. Over-hunting
  3. Habitat destruction
  4. Competition with introduced species

Answer. 3. Habitat destruction

Question 48. The main reason for extinction of species is

  1. Hunting
  2. Destruction of habitat
  3. Pollution
  4. None of these

Answer. 2. Destruction of habitat

Question 49. Wildlife is destroyed most when

  1. Mass scale hunting for foreigan trade
  2. Natural habitat is destroyed
  3. There is lack of proper care
  4. There is natural calamity

Answer. 2. Natural habitat is destroyed

Question 50. Wildlife is conserved in

  1. In situ
  2. Ex situ
  3. Both (1) and (2)
  4. None of these

Answer. 3. Both (1) and (2)

Question 51. Establishment of national parks and sanctuaries is a strategy for

  1. Conservation of wildlife
  2. Studying wildlife biology
  3. Creating awareness about wildlife
  4. Preventing wild animals entering villages

Answer. 1. Conservation of wildlife

Question 52. India now has

  1. 10 biosphere reserves, 50 national parks, and 400 wildlife sanctuaries
  2. 14 biosphere reserves, 50 national parks, and 400 wildlife sanctuaries
  3. 10 biosphere reserves, 90 national parks, and 448 wildlife sanctuaries
  4. 10 biosphere reserves, 96 national parks, and 441 wildlife sanctuaries

Answer. 4. 10 biosphere reserves, 96 national parks, and 441 wildlife sanctuaries

Question 53. An example for in situ biological conservation method is to establish

  1. Zoos
  2. Seed banks
  3. Botanical gardens
  4. Biosphere reserves

Answer. 4. Biosphere reserves

Question 54. Dachigam National Park in Srinagar is associated with the animal

  1. Hangul
  2. Rhino
  3. Musk deer
  4. Nilgiri tahr

Answer. 1. Hangul

Question 55. Dachigam sanctuary is located in

  1. WB
  2. MP
  3. J&K
  4. Rajasthan

Answer. 3. J&K

Question 56. Identify the odd combination of the habitat and the particular animal concerned:

  1. Periyar – Elephant
  2. Rann of Kutch – Wild ass
  3. Sunderbans – Bengal tiger
  4. Dachigam National Park – Snow leopard

Answer. 4. Dachigam National Park – Snow leopard

Question 57. National animal of India is

  1. Lion
  2. Tiger
  3. Antelope
  4. Elephant

Answer. 2. Tiger

Question 58. “Project Tiger” in India was launched in the year

  1. 1973
  2. 1981
  3. 1985
  4. 1988

Answer. 1. 1973

Question 59. “Project Tiger” in India was launched following the recommendation of

  1. IBWL
  2. BNHS
  3. CITES
  4. NWAP

Answer. 1. IBWL

Question 60. Identify the correct match between tiger reserve and its state?

  1. Palamu – Odisha
  2. Manas – Assam
  3. Bandipur – Tamil Nadu
  4. Corbett – Madhya Pradesh

Answer. 2. Manas – Assam

Question 61. Bandipur National Park is associated with

  1. Tiger
  2. Deer
  3. Elephant
  4. Rhinoceros

Answer. 1. Tiger

Question 62. Bandipur in Karnataka is the site of

  1. Project Tiger
  2. Project Hangul
  3. Project Peacock
  4. Project Elephant

Answer. 1. Project Tiger

Question 63. Which of the following is the smallest tiger reserve?

  1. Simlipal
  2. Palamau
  3. Namdapha
  4. Ranthambore

Answer. 4. Ranthambore

Question 64. The Ranthambore National Park is located in

  1. Gujarat
  2. Rajasthan
  3. Uttar Pradesh
  4. Maharashtra

Answer. 2. Rajasthan

Question 65. Kanha National Park is famous for

  1. Birds
  2. Tigers
  3. Crocodiles
  4. Rhinoceros

Answer. 2. Tigers

Question 66. Recently attempts are being made to reintroduce tigers in this famous National Park:

  1. Sarika
  2. Kanha
  3. Corbett
  4. Bandavgarh

Answer. 1. Sarika

Question 67. Sarika Tiger Reserve is located in

  1. Odisha
  2. Assam
  3. Rajasthan
  4. West Bengal

Answer. 3. Rajasthan

Question 68. Royal Bengal Tiger is conserved in

  1. Gir forest
  2. Sunderbans
  3. Kanha National Park
  4. Jim Corbett National Park

Answer. 2. Sunderbans

Question 69. The largest number of tigers is reported from

  1. Manas
  2. kanha
  3. Simlipal
  4. Sunderbans

Answer. 4. Sunderbans

Question 70. All Sunderban tigers are

  1. Man-eaters
  2. Good swimmers
  3. Eaters of fish and crabs
  4. All of the above

Answer. 4. All of the above

Question 71. The first white tiger in the world was found in

  1. Gir in Saurashtra
  2. Sunderbans in Bengal
  3. Rewa in Madhya Pradesh
  4. Jim Corbett National Park in Uttarakhand

Answer. 2. Sunderbans in Bengal

Question 72. Which is correct about white tiger?

  1. It is a type of albino.
  2. It is a recessive mutant.
  3. It is a transgenic animal.
  4. It is a part of subspecies of Indian tiger.

Answer. 2. It is a recessive mutant.

Question 73. If the Bengal Tiger becomes extinct,

  1. Its gene pool will be lost for ever
  2. Hyenas and wolves will become scarce
  3. The wild areas will be safe for man and domestic animals
  4. The populations of beautiful animals like deers will get stabilized

Answer. 1. Its gene pool will be lost for ever

Question 74. Sacred groves are found in

  1. Bihar
  2. Punjab
  3. Meghalaya
  4. Jammu and Kashmir

Answer. 3. Meghalaya

Question 75. Conservation of organism in natural habitat is called

  1. Ex situ conservation
  2. In situ conservation
  3. Both (1) and (2)
  4. None of the above

Answer. 2. In situ conservation

Question 76. In situ conservation of natural genetic resources can be achieved by establishing

  1. National Parks
  2. Wildlife sanctuaries
  3. Biosphere reserves
  4. All of these

Answer. 4. All of these

Question 77. What is common to the techniques (1) in vitro fertilization, (2) cryopreservation, and (3) tissue culture?

  1. All are in situ conservation methods.
  2. All are ex situ conservation methods.
  3. All require ultra modern equipment and large space.
  4. All are methods of conservation of extinct organisms.Answer. 2. All are ex situ conservation methods.

Question 78. BNHS is the abbreviated form for

  1. Border Natural History Society
  2. Bombay National History Society
  3. Border National History Services
  4. Bombay Natural History Societes

Answer. 4. Bombay Natural History Societes

Question 79. The emblem of Bombay Natural History Society (BNHS) is given. Identify the bird.

NEET Biology Biodiversity And Conservation Question 46

  1. Eagle
  2. Erget
  3. Kingfisher
  4. Hornbill

Answer. 4. Hornbill

Question 80. Which one of the following bird is endangered?

  1. Kite
  2. Parrot
  3. Hornbill
  4. Pigeon

Answer. 3. Hornbill

Question 81. The World Animal Welfare Day is celebrated on

  1. March 21
  2. June 5
  3. October 3
  4. October 4

Answer. 4. October 4

Question 82. 21st March is

  1. World Forest Day
  2. World Animal Day
  3. World Environment Day
  4. World Habitat Day

Answer. 1. World Forest Day

Question 83. The world biodiversity day is celebrated annually on

  1. 5th June
  2. 22nd April
  3. 29th December
  4. 16th September

Answer. 3. 29th December

Question 84. World Wildlife Week is celebrated on

  1. June 15-22
  2. March 1-7
  3. October 1-7
  4. June 1-7

Answer. 3. October 1-7

Question 85. Who have recently tried to put price tags on nature’s life support services?

  1. Nile Perch and his colleagues
  2. Herbert Boyer and his colleagues
  3. Ramdeo Misra and his colleagues
  4. Robert Costanza and his colleagues

Answer. 4. Robert Costanza and his colleagues

Question 86. Match Column 1 with Column 2 and select the correct answer using the codes given.

Column 1                                   Column 2

A. World Habitat Day              1. December 3

B. World Environment Day     2. October 3

C. World Conservation Day    3. March 21

D. World Forestry Day            4. June 5

  1. A = 4, B = 1, C = 3, D = 2
  2. A = 2, B = 4, C = 1, D = 3
  3. A = 2, B = 1, C=4, D=3
  4. A = 3, B = 4, C=2, D=1

Answer. 2. A = 2, B = 4, C = 1, D = 3

Question 87. Choose the wrongly matched pair:

  1. Carrot grass – Lantana
  2. Wildlife safari parks – Ex situ conservation
  3. Amazon rain forest – Lungs of the planet
  4. Khasi and Jaintia Hills – Meghalaya
  5. World Summit on Sustainable – Johannesburg Development, 2002

Answer. 1. Carrot grass – Lantana

Question 88. The relation between species richness and area is described on a logarithmic scale by the equation [where S is species richness, A is area, Z is the slope of the line (regression coefficient), C is the Y-intercept].

  1. log S = log C
  2. log S = Z log A
  3. log S = log C-Z log A
  4. log S = log C+ Z log A
  5. log C = log S+ Z log A

Answer. 4. log S = log C+ Z log A

Question 89. Sacred groves are specially useful in

  1. Preventing soil erosion
  2. Year round flow of water in river
  3. Generating environment awareness
  4. Conserving rare and threatened species

Answer. 4. Conserving rare and threatened species

Question 90. Select the correct statement about biodiversity:

  1. The desert areas of Rajasthan and Gujarat have a very high level of desert animal species as well as numerous rare animals.
  2. Large scale planting of Bt-cotton has no adverse effect on biodiversity.
  3. Western Ghats have a very high degree of species richness and endemism.
  4. Conservation of biodiversity is just a fad pursued by the developed countries.

Answer. 3. Western Ghats have a very high degree of species richness and endemism.

Question 91. Which of the following plants are commonly found in Sunderban Biosphere Reserve?

  1. Cactus
  2. Conifers
  3. Juniperus
  4. Mangroves

Answer. 4. Mangroves

Question 92. All the following are included under in situ conservation except

  1. National park
  2. Sanctuary
  3. Botanical garden
  4. Biosphere reserve

Answer. 3. Botanical garden

Question 93. Slash and burn agriculture is the other name of

  1. Step farming
  2. Crop rotation
  3. Organic garden
  4. Jhum cultivation

Answer. 4. Jhum cultivation

Question 94. Which one of the following is not a wildlife conservation project?

  1. Project Dodo
  2. Project Tiger
  3. Project Hangul
  4. Project Indian Bustard

Answer. 1. Project Dodo

NEET Biology Notes – Biodiversity And Conservation

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NEET Biology For Biodiversity And Conservation Introduction

The occurrence of different types of genes, gene pools, species, habitats, and ecosystem in a particular place and various parts of the earth is called biodiversity (term popularized by Edward Wilson).

Currently, the number of predescribed species of all plants and animals is slightly more than 1.5 million.

Robed May estimated global species diversity at about 7 million (means only 22% of total diversity has been recorded so far).

NEET Biology For Estimates Of Species Number On Earth And In India

  • Of the total estimate, more than 70% are animals while plants (including fungi) comprise no more than 22%. The most species-rich taxonomic group is insect (70% of animals).
  • The number of fungal species in the world is more than the combined total of fishes, amphibians, reptiles, and mammals.
  • No estimations are available for prokaryotes as consell giventional taxonomic methods are not suitable, and many of them are not culturable. We may accept bio-chemical/molecular criteria of estimation of diversity in this group.
  • India has 2.4% of world’s land, with 8.1% of global diversity. So, India is among 12 mega-diverse countries.
  • Nearly 45,000 plant species and twice as many animal species have been recorded from India.
  • Applying May’s method, more than 1,00,000 plant and 3,00,000 animals species are yet to be discovered and described.
  • Approximately 15,000 new species are discovered every year.

Read and Learn More NEET Biology Notes

NEET Biology For Levels Of Biodiversity

There are three types of biodiversity:

  • Genetic diversity
    • It is a measure of variety in genetic information contained in the organism, e.g., 10-150 genes in virus, 450-700 genes in Mycoplasma, and 32,000-50,000 genes in Oryza sativa.
    • It enables a population to adapt to its environment, e.g., Rauwolfia vomitoria in Himalayan ranges.
    • It helps in the formation of ecotype.
    • It plays a key role in the process of speciation. It maintains diversity at the community level.
  • Species diversity
    • It is the variety of species within a region, e.g., Western Ghats are more diverse than Eastern Ghats.
    • Species richness is the number of species present within a unit area.
    • Species diversity is the product of species richness and species evenness.
    • Maximum/taxonomic diversity occurs where the species of taxonomically different groups occur in almost equal abundance.
    • Species evenness is the proportionate number of individuals of different species.
  • Community or ecosystem diversity

It is of three types (Whittaker):

    • a-diversity (within community diversity): It is also called local diversity. It is diversity within a community.
    • B-diversity (between community diversity): It is calculated by dividing y by a diversity. It is diversity between two communities.
    • y-diversity: It is also called regional diversity. It represents the total richness of species in all the habitats found within a region, geographical area, or landscape. For example, India is more diverse than Norway.

Patterns of Biodiversity

  • The degree of biodiversity shows two master gradients: latitudinal and altitudinal.
  • Biodiversity increases from high to low latitudes, i.e., from the poles to the equator.
  • Biodiversity is minimum in arctic, moderate in temperate, and maximum in tropical regions. With very few exceptions, tropics (latitudinal range of 23.5° N to 23.5° S) harbor more species than temperate or polar areas. Colombia located near the equator has nearly 1,400 species of birds while New York at 41° N has 105 species and Greenland at 71° N has only 56 species.
  • India with much of its land area in the tropical latitudes has more than 1200 species of birds. A forest in a tropical region such as Equador has up to 10 times as many species of vascular plants as in a forest of equal area in a temperate region such as the Midwest of the USA. The largely tropical Amazonian rain forest in South America has the greatest biodiversity on the earth.
  • It is home to more than 40,000 species of plants, 3000 of fishes, 1300 species of birds, 427 species of mammals, 427 species of amphibians, 378 species of reptiles, and more than 1,25,000 species of invertebrates. Scientists estimate that in these rain forests, there might be at least 2 million insect species waiting to be discovered and named.

” biodiversity class 12 notes”

  • Tropics show greater diversity because of the following reasons:
    • Speciation is generally a function of time. Unlike temperate regions subjected to frequent glaciations in the past, tropical latitudes have remained relatively undisturbed for millions of years and, thus, had a long evolutionary time for species diversification,
    • Tropical environments are less seasonal, are relatively more constant and predictable, can promote niche specialization, and lead to a greater species diversity.
    • Species-area relationships: Alexander Humboldt observed that within a region, species richness increased with increasing explored area, but only up to a limit. In fact, the relation between species richness and area for a wide variety of taxa (angiosperm plants, birds, bats, freshwater fishes) turns out to be a rectangular hyperbola.
      The relationship is a straight line described by the equationlog S = log C + Z log Awhere S is species richness, A is area, Z is the slope of the line (regression coefficient), and C is the Y-intercept.

NEET Biology Biodiversity And Conservation Species area relationship

  • Ecologists have discovered that the value of Z lies in the range of 0.1 to 0.2, regardless of the taxonomic group or region. If we analyze the species area relationships among very large areas such as the entire continents, the slope of the line will be much steeper (Z values in the range of 0.6 to 1.2). For frugivorous (fruit-eating) birds and mammals in the tropical forests of different continents, the slope is found to be 1.15.
  • Diversity decreases from lower to higher altitudes on a mountain, i.e., it is maximum at the base.
  • Conditions favoring growth do not induce biodiversity or speciation; it is called the paradox of enrichment.

Importance of Species Diversity to the Ecosystem

Community with more species is more stable. Stable community should not show too much variation in productivity per year and must be resistant or resilient to occasional disturbances by natural or anthropogenic agencies and alien species. Ecosystem health/balance will be severely affected if species. extinction (particularly key stone) occurs.

biodiversity and conservation ncert

NEET Biology For Biodiversity Conservation

  • Narrowly utilitarian aspect:
    • Pinus, Abies, and Boswellia are major sources of paper.
    • Pine resin is obtained from Pinus while damar is obtained from Shorea robusta.
    • Gums: Kuteera gum (Stericulia urens), Bengal kino gum (Butea monosperma), salai (Boswellia serrata), dhaora (Anogeissus latifolia), gum Arabic (Acacia senegal), etc.
    • Tannin sources: Uncaria (leaves and young branches), Acacia (bark), Juglans (bark), and Caesalpinia (wood and fruits).
    • Important dyes: Cutch/kattha (heartwood of Acacia catechu), henna (leaves of Lawsonia inermis), and haematoxylon (heartwood of Haematoxylon campechianum).
    • Plants can also be used to manufacture innumerable synthetic products called botanochemicals.

NEET Biology Biodiversity And Conservation Some important drugs

  • Broadly utilitarian aspect: Ecosystem services are important.
  • Ethical aspect: Every species has an intrinsic value.
  • Loss of Biodiversity IUCN Red List documents the extinctions of 784 species (including 338 vertebrates, 359 invertebrates, and 87 plants) in the last 500 years.
  • Some recent extinctions: Dodo (Mauritius), Quagga (Africa), Thylacine (Australia), Steller’s sea cow (Russia), and three subspecies (Bali, Javan, and Caspian) of tiger.
  • 27 species have disappeared in the last 20 years.
  • Presently, 12% birds species, 23% of all mammals, 32% of all amphibians, and 31% of all gymnosperms in the world are facing the threat of extinction (more than 15,500 species).
  • The sixth extinction is 100-1000 times faster.
  • This may lead to decline in plant production, lowered resistance, and increased variability in ecosystem processes, e.g., pest and disease cycle.

Causes of Biodiversity Losses

  • Important factors that cause loss of biodiversity are habitat loss, habitat fragmentation, disturbance, over exploitation, pollution, exotic species, intensive agriculture, and forestry (growing only exploitable forest plants).
  • Habitat destruction or loss is the primary cause of the loss of biodiversity (tropical rain forests were once covering 14% while now they cover 6% only), Amazon valley.
  • Habitat fragmentation reduces the core area and in- creases the edge area.
  • Dodo of Mauritius, messenger pigeon, Steller’s sea cow, and Tasmanian wolf have become extinct due to overexploitation. Heath hen disappeared due to hunting and habitat destruction.
  • Exotic (alien) species becoming invasive is considered another potent factor for the extinction of species.
  • Examples of some exotic species: Water hyacinth (Eichhornia crassipes), Lantana (Lantana camera), congress grass (Parthenium hysterophorus), Nile perch, Eupatorium (Eupatorium cdoratum), and African catfish (Clarias gariepinus).
  • Coextinction: For example, coevolved species.

Susceptibility to Extinction

Species more susceptible to extinction have the following population characteristics:

  • Large body size (e.g., rhinoceros and lion)
  • Small population size and low reproductive rate (e.g., giant panda and blue whale)
  • High trophic level in food chain (e.g., bald eagle and Bengal tiger)
  • Fixed habitat and migratory routes (e.g., whooping crane and blue whale)

IUCN Red List

  • World Conservation Union (WCU) which was formerly known as International Union for the Conservation of Nature and Natural Resources (IUCN), headquarter at Mc-den, Switzerland, has recognized eight Red List categories of species. They are extinct, extinct in wild, critically endangered, endangered, vulnerable, lower risk, data deficient, and not evaluated.
  • Critically endangered, endangered, and vulnerable species are called threatened species.
  • Rare species have a small population and these are nei- ther vulnerable nor endangered but are at risk.
  • A taxon is critically endangered when it is facing an extremely high risk of extinction in the wild in the immediate future.
  • A taxon is endangered when it is facing a high risk of extinction in the wild in the near future.
  • A taxon is vulnerable when it is facing a high risk of extinction in the wild in the medium term future.

” biodiversity introduction pdf”

NEET Biology Biodiversity And Conservation IUCN Red List

Conservation of Biodiversity

There are two types of conservation strategies: in situ (on site) and ex situ (off site).

In situ Conservation

  • Examples of protected areas: National parks, wildlife sanctuaries, and biosphere reserves.
  • World Conservation Monitoring Center has recognized 37,000 protected areas.
  • There are 448 wildlife sanctuaries and 90 national parks in India.
  • In wildlife sanctuaries, protection is given only to animal life while in national parks, both flora and fauna are protected.
  • The concept of biosphere reserves was launched under the MAB program of UNESCO (started in 1975).Total biosphere reserves in India are 14.
  • A biosphere reserve is made of core, buffer, and transition zones. In core or natural zone, no human activity is allowed.
  • Research and educational activities are allowed in buffer zone.
  • Activities such as settlements, cropping, grazing, forestry, and tourism are allowed in transition zone.

NEET Biology Biodiversity And Conservation Conservation of Biodiversity

Scared Grooves

  • Sacred forests (islands of pristine forests): Examples are forests of Jaintia and Khasi (Meghalaya), Aravalli (Rajasthan), Western Ghats (Maharashtra and Karnataka), Surguja, Chanda, and Bastar area (MP).
  • Sacred lakes: Examples are Pushkar lake in Rajasthan and Khecheopalri lake in Sikkim.
  • Sacred plants: Examples are Ocimum sanctum (tulsi), Elaeocarpus floribundus, and Ficus religiosa.

Ex situ Conservation Strategies

  • These include botanical gardens, zoological parks and wildlife safari parks, arboreta, aquaria, seed bank, DNA banks, tissue culture, horticultural trade, etc.
  • Cryopreservation (at temperature 196°C) is useful for conserving vegetatively propagated crops, e.g., potato. There are two types of cryopreservation:
    • Very rapid cooling (e.g., storing seeds)
    • Gradual cooling and simultaneous dehydration (e.g., tissue culture)
  • More than 1500 botanical gardens and arboreta and 800 professionally managed zoos are present around the world.

Biodiversity Hotspots

  • The concept was developed by Norman Myers in 1988. Spots with accelerated habitat loss are priority areas for in situ conservation. These areas show high species richness and high endemism.
  • India with 2.4% land area accounts approximately 8% species of the world.
  • Initially 25 terrestrial hotspots were identified glob- ally. But now the number is raised to 34 with an area of less than 2%.
  • Among 34, three (Western Ghats and Sri Lanka, Indo Burma, and Himalayas) are found in India. Eastern Himalayas are active center of evolution of many angiosperms and have many primitive angiosperms.
  • The protection of these areas can reduce mass extinction by almost 30%.
  • IUCN and WWF (World Wide Fund for Nature) are leading international organizations concerned with biodiversity conservation.

Some Abbreviations

  • NEERI: National Environment Engineering Research Institute
  • UNEP: United Nations Environment Program
  • CAZRI: Central Arid Zone Research Institute (Jodhpur)
  • BRP: Biosphere Reserve Program
  • MAB: Man and Biosphere
  • IBWL: Indian Board of Wild Life
  • CITES: Convention on International Trade in Endangered Species
  • CBD: Convention on Biological Diversity (The Earth Summit, 1992)

 

NEET Biology For Assertion-Reasoning Questions

In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R).

  1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark (1).
  2. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
  3. If Assertion is true but Reason is false, then mark (3).
  4. If both Assertion and Reason are false, then mark (4).

Question 1. Assertion: Western Ghats are included among the hot spots of biodiversity.

Reason: Western Ghats have greater amphibian diversity than Eastern Ghats.

Answer. 2. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark (2).

” introduction to biodiversity pdf”

Question 2. Assertion: Tropical regions are more diversity-rich in comparison to temperate areas.

Reason: Availability of more solar energy directly affects the presence of more species in these areas.

Answer. 3. If Assertion is true but Reason is false, then mark (3).

Question 3. Assertion: The process of extinction is random.

Reason: Any species not adapted to environmental conditions cannot survive.

Answer. 4. If both Assertion and Reason are false, then mark (4).

Question 4. Assertion: Habitat destruction is the main reason of loss of biodiversity.

Reason: This actually causes the increase in edge area and reduction in core area.

Answer. 3. If Assertion is true but Reason is false, then mark (3).

Question 5. Assertion: Pristine forests are among in situ conservation strategies.

Reason: These are sacred grooves where biota is protected on site.

Answer. 1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark (1).

NEET Biology Multiple Choice Questions – Ecosystem

by

NEET Biology For Ecosystem Multiple Choice Questions

Question 1. Which is not true regarding ecosystem?

  1. Self-sufficient unit.
  2. Cyclic exchange of materials between living beings and environment.
  3. Only requirement is input of energy.
  4. Characterized by a major vegetation type.

Answer. 4. Characterized by a major vegetation type.

Question 2. Which is not a structural aspect of ecosystem?

  1. Productivity
  2. Species composition
  3. Diversity
  4. Life cycle

Answer. 1. Productivity

Question 3. The amount of living material and nutrients present in different trophic levels and soils at any given time are called, respectively,

  1. Standing state and standing crop
  2. Standing crop and standing state
  3. Standing state and standing quality
  4. Biomass and standing crop

Answer. 2. Standing crop and standing state

Question 4. An ecosystem contains

  1. Green plants and animals
  2. Green plants and decomposers
  3. Green plants, animals, decomposers, and abiotic environment
  4. Producers and consumers

Answer. 3. Green plants, animals, decomposers, and abiotic environment

Question 5. When a habitat is subdivided into parts which show distinct properties, it is called

  1. Mini-habitat
  2. Micro-habitat
  3. Mega-habitat
  4. Macro-habitat

Answer. 2. Micro-habitat

Question 6. Which of the following are artificial aquatic ecosystems?

  1. Large dams and reservoirs
  2. Lakes and canals
  3. Aquarium and pond
  4. All of these

Answer. 4. All of these

Question 7. The amount of biogenetic nutrients present in the abiotic environment per unit area at any time is called

  1. Standing state
  2. Standing crop
  3. NPP
  4. Nutrients immobilization

Answer. 1. Standing state

Question 8. Which of the following is a functional aspect of an ecosystem?

  1. Species composition
  2. Inorganic nutrients
  3. Homeostasis
  4. Topography

Answer. 3. Homeostasis

Question 9. Which of the following are called key industry animals?

  1. Autotrophs
  2. Decomposers
  3. Herbivores
  4. Top carnivores

Answer. 3. Herbivores

Question 10. NPP is given by the formula

  1. NPP GPP × 100
  2. NPP = GDP – Secondary productivity
  3. NPP = GPP- Respiration rate
  4. NPP = GPP/100

Answer. 3. NPP = GPP- Respiration rate

Question 11. Which of the following ecosystems has the highest productivity?

  1. Tropical deciduous forest
  2. Temperate coniferous forest
  3. Tropical rain forest.
  4. Desert shrub

Answer. 3. Tropical rain forest.

Question 12. For NPP, energy captured is

  1. 1-5% of incident radiation
  2. 2-5% of PAR
  3. 0.8-4% of incident radiation
  4. 2-10% of PAR

Answer. 3. 0.8-4% of incident radiation

Question 13. Plant life is restricted in sea to

  1. Photic zone or euphotic zone
  2. Aphotic zone
  3. Abyssal area
  4. Continental shelf

Answer. 1. Photic zone or euphotic zone

Question 14. Gross primary productivity is

  1. Rate at which organic molecules are formed in an autotroph
  2. Rate at which organic molecules are used up by autotroph
  3. Storage of organic molecules in the body of an autotroph
  4. Rate at which organic molecules are transferred to the next higher trophic level

Answer. 1. Rate at which organic molecules are formed in an autotroph

Question 15. In tropical rain forest, most of the energy in ecosystem flows through

  1. Grazing food chain
  2. Detritus food chain
  3. Parasitic food chain
  4. Both (1) and (3)

Answer. 2. Detritus food chain

Question 16. The respiratory losses of producers, herbivores, and carnivores are, respectively,

  1. 10%, 20%, 30%
  2. 20%, 30%, 60%
  3. 20%, 40%, 80%
  4. Always 10%

Answer. 2. 20%, 30%, 60%

Question 17. Which of the following ecological pyramids can be both upright and inverted?

  1. Pyramid of number
  2. Pyramid of biomass
  3. Pyramid of energy
  4. Both (1) and (2)

Answer. 4. Both (1) and (2)

Question 18. Which of the following ecological pyramids is the most representative of the functional characteristics of an eco-system?

  1. Pyramid of number
  2. Pyramid of biomass
  3. Pyramid of energy
  4. All are equally representative

Answer. 3. Pyramid of energy

questions for ecology

Question 19. (NPP/GPP) × 100 is

  1. Assimilation efficiency
  2. Net production efficiency
  3. Ecological efficiency
  4. Photosynthetic efficiency

Answer. 2. Net production efficiency

Question 20. Which is not true for humus?

  1. Dark colored amorphous substance
  2. Highly resistant to microbial action
  3. Acts as reservoir of nutrients and increases water holding capacity of soil
  4. Degradation product of proteins and fats and produced by the process of mineralization

Answer. 4. Degradation product of proteins and fats and produced by the process of mineralization

Question 21. Nutrient immobilization

  1. Prevents leaching of nutrients
  2. Is incorporation of nutrients in microbes.
  3. Is covalent linking of nutrients with one another
  4. More than one option is correct

Answer. 4. More than one option is correct

Question 22. If producer is a large tree that supports a number of herbivorous animals which are further attacked by ectoparasites, the pyramid of number shall be

  1. Inverted
  2. Upright
  3. Irregular
  4. Spindle shaped

Answer. 1. Inverted

Question 23. Ecological pyramids are also called

  1. Pyramids of number
  2. Eltonian pyramids
  3. Pyramids of energy
  4. Pyramids of biomass

Answer. 2. Eltonian pyramids

Question 24. A food web

  1. Increases the variety of food at each trophic level
  2. Delicately balances the inter-relations amongst organisms
  3. Decreases the variety of food but increases the quantity of food at each trophic level
  4. Increases the variety as well as the quantity of food at each trophic level

Answer. 4. Increases the variety as well as the quantity of food at each trophic level

Question 25. Ten percent law of energy transfer in a food chain was enunciated by

  1. Elton
  2. Lindeman
  3. Haeckel
  4. SchimperAnswer. 2. Lindeman

Question 26. The importance of ecosystem lies in

  1. Flow of energy
  2. Cycling of materials
  3. Both (1) and (2)
  4. Consumers

Answer. 3. Both (1) and (2)

Question 27. Earth is an

  1. Open system
  2. Closed system
  3. Both (1) and (2)
  4. None of these

Answer. 3. Both (1) and (2)

Question 28. Biogeochemical cycle having a small gaseous component is found in

  1. Phosphorus
  2. Nitrogen
  3. Carbon
  4. Sulfur

Answer. 4. Sulfur

Question 29. Annually, 1 ha of a healthy forest will

  1. Produce 10 ton of O2 and absorb 10 ton of CO2
  2. Produce 20 ton of O, and absorb 20 ton of CO2
  3. Produce 10 ton of O, and absorb 30 ton of CO2
  4. Produce 30 ton of O, and absorb 30 ton of CO2

Answer. 3. Produce 10 ton of O, and absorb 30 ton of CO2

Question 30. How many overlapping water cycles are found in nature?

  1. Two
  2. Three
  3. One
  4. There is no overlapping cycle

Answer. 1. Two

Question 31. Phosphates remain outside the natural cycle for a long time

  1. When they form compounds with metals
  2. When they are incorporated in bones and teeth
  3. When the bodies of the organisms excrete and decompose
  4. Both (1) and (2)

Answer. 4. Both (1) and (2)

Question 32. Human dominated environment is called

  1. Biosphere
  2. Noosphere
  3. Socio-cultural environment
  4. None of these

Answer. 2. Noosphere

Question 33. Energy requirement for the maintenance of body with successively higher trophic level

  1. Decreases
  2. Increases
  3. Remains same
  4. Is always 10%

Answer. 2. Increases

Question 34. In which of the following biogeochemical cycles is atmospheric phase absent/negligible?

  1. Nitrogen
  2. Sulfur
  3. Phosphorus
  4. Water

Answer. 3. Phosphorus

Question 35. Stratification is well developed in

  1. Tropical rain forests
  2. Grasslands
  3. Alpine vegetations
  4. Temperate forests

Answer. 1. Tropical rain forests

Question 36. An orderly sequence of community development on an area is called

  1. Succession
  2. Cover
  3. Establishment
  4. Diversity

Answer. 1. Succession

Question 37. The terminal stage of a successional process is called

  1. Final stage
  2. Climax stage
  3. Seral stage
  4. Pioneer stage

Answer. 2. Climax stage

Question 38. If the pioneer stage is dominated by autotrophs, then the succession is called

  1. Allogenic
  2. Autogenic
  3. Autotrophic
  4. Heterotrophic

Answer. 3. Autotrophic

Question 39. Which is not a characteristic of sera stages?

  1. Simplified food chain
  2. Few and generalized niches
  3. Low NPP
  4. Low energy use efficiency

Answer. 3. Low NPP

Question 40. Succession stage that occurs on a bare rock is called

  1. Psammosere
  2. Xerosere
  3. Lithosere
  4. Haloscre

Answer. 3. Lithosere

Question 41. Serial changes in the previously sterile or total barren area are called

  1. Climatic climax
  2. Secondary succession
  3. Primary succession
  4. Sere

Answer. 3. Primary succession

Question 42. Pond is an example of ecosystem.

  1. Artificial
  2. Natural
  3. Forest
  4. Grassland

Answer. 2. Natural

Question 43. Which of the following is the most productive ecosystem?

  1. Estuary
  2. Open sea
  3. Desert
  4. MountainAnswer. 1. Estuary

Question 44. The pyramid of energy in a forest ecosystem is

  1. Always upright
  2. Always inverted
  3. Both upright and inverted
  4. None of the above

Answer. 1. Always upright

Question 45. The importance of ecosystem is

  1. Flow of energy
  2. Cycling of materials
  3. Both (1) and (2)
  4. None of the above

Answer. 3. Both (1) and (2)

Question 46. Which is the correct path of energy flow in an ecosystem?

  1. Producers → Carnivores Herbivores → Decomposers
  2. Producers → Herbivores → Carnivores → Decomposers
  3. Herbivores → Carnivores → Producers → Decomposers
  4. Herbivores → Producers → Carnivores → Decomposers

Answer. 2. Producers → Herbivores → Carnivores → Decomposers

ecology questions

Question 47. The number of primary producers within a specified area would be maximum in

  1. Grassland ecosystem
  2. Forest ecosystem
  3. Pond ecosystem
  4. Deserts

Answer. 3. Pond ecosystem

Question 48. A food chain starts with

  1. Nitrogen fixation organisms
  2. Photosynthesizing organisms
  3. Respiration
  4. Decomposers

Answer. 2. Photosynthesizing organisms

Question 49. Nepenthes is a

  1. Primary producer
  2. Consumer
  3. Both primary producer and consumer
  4. None of the above

Answer. 3. Both primary producer and consumer

Question 50. Biological equilibrium is found among

  1. Producers and consumers
  2. Producers and decomposers
  3. Producers, consumers, and decomposers
  4. Producers and light

Answer. 1. Producers and consumers

Question 51. The number of individuals of a species in a particular ecosystem at a given time remains constant due to

  1. Man
  2. Parasites
  3. Predators
  4. Available food

Answer. 4. Available food

Question 52. The two components of an ecosystem are

  1. Biotic and abiotic
  2. Plants and animals
  3. Weeds and microorganisms
  4. Plants and light

Answer. 1. Biotic and abiotic

Question 53. The pyramid of number in a grassland ecosystem is

  1. Linear
  2. Upright
  3. Irregular
  4. Inverted

Answer. 2. Upright

Question 54. The cycling of elements in an ecosystem is called.

  1. Chemical cycle
  2. Biogeochemical cycle
  3. Geological cycle
  4. Geochemical cycle

Answer. 2. Biogeochemical cycle

Question 55. Which of the following bacteria has potential for nitrogen fixation?

  1. Nitrosomonas
  2. Nitrobacter
  3. Nitrosococcus
  4. Rhizobium

Answer. 4. Rhizobium

Question 56. Ecosystem has

  1. Plant and animal
  2. Air and H2O
  3. Soil and light
  4. Biotic and abiotic components

Answer. 4. Biotic and abiotic components

Question 57. Sal and teak are found in

  1. Tropical rain forest
  2. Tropical deciduous forest
  3. Temperature board leaf forest
  4. Temperature needle leaf forest

Answer. 2. Tropical deciduous forest

Question 58. Decomposers are

  1. Autotrophs
  2. Heterotrophs
  3. Organotrophs
  4. Autoheterotrophs

Answer. 2. Heterotrophs

“the natural residence of every organism is known as “

Question 59. During food chain, the maximum energy is stored in

  1. Producers
  2. Decomposers
  3. Herbivores
  4. Carnivores

Answer. 1. Producers

Question 60. In the phosphorus cycle, weathering makes phosphate available first to

  1. Decomposers
  2. Consumers
  3. Producers
  4. All the above

Answer. 3. Producers

Question 61. In a food chain, the total amount of living material is depicted by

  1. Pyramid of biomass
  2. Pyramid of energy
  3. Pyramid of number
  4. Trophic levels

Answer. 1. Pyramid of biomass

Question 62. Nitrates are converted to nitrogen by

  1. Nitrogen fixing bacteria
  2. Ammonification bacteria
  3. Denitrifying bacteria
  4. Nitrifying bacteria

Answer. 3. Denitrifying bacteria

Question 63. In pond ecosystem, diatoms represent

  1. Producers
  2. Primary consumers
  3. Secondary consumers
  4. Tertiary consumers

Answer. 1. Producers

Question 64. Pyramids of biomass in pond ecosystem are

  1. Inverted
  2. Upright
  3. Linear
  4. Irregular

Answer. 1. Inverted

Question 65. Lion is kept under in Eltonian pyramid as

  1. Producer
  2. Primary consumer
  3. Secondary consumer
  4. Tertiary consumer

Answer. 4. Tertiary consumer

Question 66. Bacteria and fungi developing on dead decaying organisms are

  1. Parasites
  2. Commensals
  3. Saprophytes
  4. Symbionts

Answer. 3. Saprophytes

Question 67. Phytoplanktons are important biotic components of

  1. Grassland
  2. Pond ecosystem
  3. Forest ecosystem
  4. None of these

Answer. 2. Pond ecosystem

“the natural residence of every organism is known as: “

Question 68. Which ecological pyramid can never occur in an inverted form?

  1. Pyramid of number
  2. Pyramid of biomass
  3. Pyramid of energy
  4. Pyramid of species richness

Answer. 4. Pyramid of species richness

Question 69. Peacock eats snake and snake eats insect while insect eats green plant. Then the position of peacock is

  1. Primary producer
  2. Secondary producer
  3. Decomposer
  4. Top at the apex of food pyramid

Answer. 1. Primary producer

Question 70. Source of energy in an ecosystem is

  1. Sun
  2. ATP
  3. Sugar made by plant
  4. Green plant

Answer. 3. Sugar made by plant

Question 71. Legume plants are important for atmosphere because they

  1. Help in NO2 fixation
  2. Do not help in NO2 fixation
  3. Increase soil fertility
  4. All of these

Answer. 4. All of these

Question 72. Tropical dense forests are due to

  1. Low rainfall and low temperature
  2. High rainfall and low temperature
  3. Low rainfall and high temperature
  4. High rainfall and high temperature

Answer. 1. Low rainfall and low temperature

Question 73. Energy enters in food chain by

  1. Producer
  2. Primary consumers
  3. Secondary consumers
  4. Tertiary consumers

Answer. 1. Producer

Question 74. In an ecosystem,

  1. Primary producers are more than primary consumers
  2. Primary consumers are larger than primary producers
  3. Secondary consumers are larger than primary producers
  4. Primary consumers least depend on primary producers

Answer. 1. Primary producers are more than primary consumers

Question 75. In which type of forest is humus formed by dry and dead leaves?

  1. Coniferous forest
  2. Deciduous forest
  3. Tundra forest
  4. Alpine

Answer. 2. Deciduous forest

Question 76. A pond is a

  1. Biome
  2. Natural ecosystem
  3. Artificial ecosystem
  4. Community of plants and animals

Answer. 2. Natural ecosystem

Question 77. The importance of ecosystem lies in

  1. Energy flow
  2. Cycling of materials
  3. Both
  4. None

Answer. 3. Both

Question 78. The concept of ecological pyramid was given by

  1. Odum
  2. Elton
  3. Darwin
  4. Reiter

Answer. 2. Elton

Question 79. Stratification is found in

  1. Tundra
  2. Tropical forest
  3. Deciduous forest
  4. Desert

Answer. 2. Tropical forest

Question 80. The driving force of ecosystem is

  1. Producers
  2. Plants with carbohydrates
  3. Biomass
  4. Solar energy

Answer. 4. Solar energy

Question 81. Ecosystem creates

  1. Food chain
  2. Food web
  3. Any of the two
  4. None

Answer. 3. Any of the two

Question 82. The term ecosystem was coined by

  1. P. Maheshwari
  2. Tansley
  3. R. Mishra
  4. P. Odum

Answer. 2. Tansley

Question 83. The importance of ecosystem lies in

  1. Flow of energy
  2. Cycling of materials
  3. Both (1) and (2)
  4. None of the above

Answer. 3. Both (1) and (2)

“ecological questions “

Question 84. A pond is a

  1. Biome
  2. Natural ecosystem
  3. Artificial ecosystem
  4. Community of plants and animals

Answer. 2. Natural ecosystem

Question 85. Which biotic components mainly help in the recycling of minerals?

  1. Producers
  2. Consumers
  3. Decomposers
  4. All the above

Answer. 3. Decomposers

Question 86. Path of energy flow in an ecosystem is

  1. Herbivorous → Producer → Carnivorous → Decomposer
  2. Herbivorous → Carnivorous → Producer → Decomposer
  3. Producer → Carnivorous → Herbivorous → Decomposer
  4. Producer → Herbivorous → Carnivorous → Decomposer

Answer. 4. Producer → Herbivorous → Carnivorous → Decomposer

Question 87. The number of primary producers in a specified area would be the maximum in

  1. Pond ecosystem
  2. Grassland ecosystem
  3. Forest ecosystem
  4. Desert ecosystem

Answer. 1. Pond ecosystem

Question 88. Carbon cycle includes (the following is a logical sequence)

  1. Producer → Consumer → Decomposer
  2. Decomposer → Consumer → Producer
  3. Producer → Decomposer → Consumer
  4. Consumer → Producer → Decomposer

Answer. 1. Producer → Consumer → Decomposer

Question 89. The bulk of nitrogen in nature is fixed by

  1. Lightening
  2. Chemical industries
  3. Denitrifying bacteria
  4. Symbiotic bacteria

Answer. 4. Symbiotic bacteria

Question 90. Hydrological cycle is controlled by

  1. Grasslands
  2. Forests
  3. Planktons
  4. Epiphytes

Answer. 2. Forests

Question 91. In India, the temperate, evergreen type of vegetation is found mostly in

  1. Western Himalayas above 3500 m
  2. Eastern and Western Himalayas less than 3500 m
  3. Rajasthan and South Punjab
  4. Western Ghats and Assam

Answer. 2. Eastern and Western Himalayas less than 3500 m

Question 92. Savannahs are

  1. Tropical rain forest
  2. Desert
  3. Grassland with scattered trees
  4. Dense forest with close canopy

Answer. 4. Dense forest with close canopy

Question 93. Biosphere refers to

  1. Plants of the world
  2. Special plants
  3. Area occupied by living beings
  4. Plants of a particular area

Answer. 3. Area occupied by living beings

Question 94. Acacia, Prosopis, and Caparis belong to

  1. Deciduous forest
  2. Tropical forest
  3. Thorn forest
  4. Evergreen forest

Answer. 3. Thorn forest

Question 95. The total amount of energy trapped by green plants in food is called

  1. Gross primary production
  2. Net primary production
  3. Standing crop
  4. Standing state

Answer. 1. Gross primary production

Question 96. In which biome may a new plant adapt soon?

  1. Tropical rain forest
  2. Desert
  3. Mangrove
  4. Sea island

Answer. 1. Tropical rain forest

Question 97. Percentage energy transferred to higher trophic level in food chain is

  1. 1%
  2. 10%
  3. 90%
  4. 100%

Answer. 2. 10%

Question 98. What is the reason for the highest biomass in aquatic ecosystem?

  1. Nanoplankton, blue green algae, green algae
  2. Sea grass and slime molds
  3. Benthonic and brown algae
  4. Diatoms

Answer. 3. Benthonic and brown algae

Question 99. Which of the following is a correct pair?

  1. Cuscuta – Parasite
  2. Dischidia – Insectivorous
  3. Opuntia – Predator
  4. Capsella – Hydrophyte

Answer. 1. Cuscuta – Parasite

Question 100. Bamboo plant is growing in a tropical rain forest. Then what will be its trophic level?

  1. First trophic level (T1)
  2. Second trophic level (T2)
  3. Third trophic level (T3)
  4. Fourth trophic level (T4)

Answer. 1. First trophic level (T1)

Question 101. Which of the following is expected to have the highest value (g/m2/yr) in a grassland ecosystem?

  1. Tertiary production
  2. Gross production (GP)
  3. Net production (NP)
  4. Secondary production

Answer. 2. Gross production (GP)

Question 102. An ecosystem which can be easily damaged but can re- cover after some time if the damaging effect stops will have

  1. High stability and low resilience
  2. Low stability and low resilience
  3. High stability and high resilience
  4. Low stability and high resilience

Answer. 4. Low stability and high resilience

Question 103. Which one of the following pairs is mismatched?

  1. Savanna – Acacia trees
  2. Coniferous forest – Evergreen trees
  3. Tundra – Permafrost
  4. Prairies – EpiphytesAnswer. 4. Prairies – Epiphytes

Question 104. Which one of the following is not used for the construction of ecological pyramids?

  1. Rate of energy flow
  2. Fresh weight
  3. Dry weight
  4. Number of individuals

Answer. 2. Fresh weight

Question 105. Which one of the following ecosystem types has the highest annual net primary productivity?

  1. Temperate deciduous forest
  2. Tropical rain forest
  3. Tropical deciduous forest
  4. Temperate evergreen forest

Answer. 2. Tropical rain forest

Question 106. Quercus species is the dominant component in

  1. Scrub forests
  2. Tropical rain forests
  3. Temperate deciduous forests
  4. Alpine forests

Answer. 3. Temperate deciduous forests

Question 107. Consider the following statements concerning food chain?

(a) Removal of 80% tigers from an area resulted in greatly increased growth of vegetation.

(b) Removal of most of the carnivores resulted in an increased population of deers.

(c) The length of food chains is generally limited to 3-4 trophic levels due to energy loss.

(d) The length of food chains may vary from 2 to 8 trophic levels.

Which of the above two statements are correct?

  1. (a), (c)
  2. (a), (b)
  3. (b), (c)
  4. (c), (d)

Answer. 3. (b), (c)

Question 108. The slow rate of decomposition of fallen logs in nature is due to their

  1. Anaerobic environment around them
  2. Low cellulose content
  3. Low moisture content
  4. Poor nitrogen content

Answer. 3. Low moisture content

Question 109. Which one of the following types of organisms occupies more than one trophic level in a pond ecosystem?

  1. Frog
  2. Phytoplankton
  3. Fish
  4. Zooplankton

Answer. 3. Fish

Question 110. Study the four statements, (A)-(D), given and select the two correct ones out of them:

(A) A lion eating a deer and a sparrow feeding on grain are ecologically similar in being consumers.

(B) Predator starfish helps in maintaining the species diversity of some invertebrates.

(C) Predators ultimately lead to the extinction of prey species.

(D) The productions of chemicals such as nicotine and strychnine by plants are metabolic disorders.

The two correct statements are

  1. (A) and (D)
  2. (A) and (B)
  3. (B) and (C)
  4. (C) and (D)

Answer. 2. (A) and (B)

Question 111. The biomass available for consumption by herbivores and decomposers is called

  1. Net primary productivity
  2. Secondary productivity
  3. Standing crop
  4. Gross primary productivity

Answer. 1. Net primary productivity

Question 112. Which of the following is one of the characteristics of a biological community?

  1. Stratification
  2. Natality
  3. Mortality
  4. Sex-ratio

Answer. 1. Stratification

Question 113. Identify the possible link “A” in the following food chain:

Plant → Insect → Frog → “A” → Eagle

  1. Wolf
  2. Cobra
  3. Parrot
  4. Rabbit

Answer. 2. Cobra

Quercus 114. In an area where DDT had been used extensively, the population of birds declined significantly because

  1. Earthworms in the area got eradicated
  2. Cobras were feeding exclusively on birds
  3. Many eggs laid by birds did not hatch
  4. Birds stopped laying eggs

Answer. 3. Many eggs laid by birds did not hatch

Question 115. The upright pyramid of numbers is absent in

  1. Forest
  2. Lake
  3. Grassland
  4. Pond

Answer. 1. Forest

Question 116. An imaginary pyramid of numbers is given. What can be one of the possibilities about certain organisms at some of the different levels?

NEET Biology Ecosystem Question 76

  1. Level PP is phytoplanktons in sea and top level TC is whale.
  2. Level one PP is pipal trees and level SC is sheep
  3. Level PC is rats and level SC is cats.
  4. Level PC is insects and level SC is small insectivorous birds.

Answer. 4. Level PC is insects and level SC is small insectivorous birds.

Quercus 117. Which one of the following is not a functional unit of an ecosystem?

  1. Decomposition
  2. Productivity
  3. Stratification
  4. Energy flow

Answer. 3. Stratification

Question 118. Which one of the following is not a gaseous biogeochemical cycle in ecosystem?

  1. Phosphorus cycle
  2. Nitrogen cycle
  3. Carbon cycle
  4. Sulfur cycle

Answer. 1. Phosphorus cycle

Question 119. The rate of formation of new organic matter by rabbit in grassland is called

  1. Net productivity
  2. Secondary productivity
  3. Net primary productivity
  4. Gross primary productivity

Answer. 2. Secondary productivity

NEET Biology Notes – Ecosystem

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NEET Biology Notes For Ecosystem Introduction

According to Tansley (who also coined the term ecosystem), the sum total of interaction between living (biotic) and non-living (abiotic) components which is capable of independent existence is called an ecosystem.

Read and Learn More NEET Biology Notes

NEET Biology Notes For Important Facts About Ecosystem

  • The flow of energy is from producer to consumers.
  • Cycling of matter takes place between biotic and abiotic components.
  • There exists functional relationship between organisms and the environment.
  • There is a great deal of biotic diversity.
  • Homeostasis (self-regulation): The ecosystem has the capacity to overcome forces which tend to disturb the balance of the ecosystem (resilience).
  • Incomplete ecosystem: An ecosystem lacking one or more structural components is called an incomplete ecosystem, e.g., deep sea and freshly formed rain water pond ecosystem.
  • Artificial ecosystems: These are man-made ecosystems. Examples are modern agriculture, dams, zoo-logical parks, plantations, aquacultures, etc.
  • The characteristics of artificial ecosystems are as follows:
    • Artificial ecosystems do not possess self-regulatory mechanism.
    • These have little diversity.
    • The food chain is simple.
    • Productivity is high.
    • There is little cycling of nutrients.

class 12 biology ch 14 notes

NEET Biology Notes For Structure And Function Of Ecosystem

Structure of Ecosystem

The structure of ecosystem depends upon the following components:

  • Species diversity components of ecosystem
  • Species composition
  • Life cycle
  • Stratification

NEET Biology Ecosystem Structure of Ecosystem

Function of Ecosystem

The edaphic functional components of ecosystem are studied with the following aspects:

  • Productivity
  • Mineral cycling
  • Energy flow
  • Food chain and web slopes
  • Efficiency
  • Biotic interrelationships
  • Homeostasis
  • Ecoregulation

Homeostasis in Ecosystem

Ecosystem maintains functional balance or homeostasis among different components. It is due to the following reasons:

  • Carrying capacity
  • Nutrient cycling
  • Self-regulation
  • Feedback

NEET Biology Notes For Ecosystem Stratification

Stratification is the structure or recognizable pattern in the spatial arrangement of the members of communities. More specifically, stratification represents vertical zonation in the community. For example, in grassland communities, there is subterranean floor containing basal portions of vegetation. However, stratification in a forest community is the most complicated where as many as five vertical subdivisions may be recognized. These vertical subdivisions are as follows:

  • Subterranean
  • Forest floor
  • Herbaceous vegetation
  • Shrubs
  • Trees

Boundaries of Ecosystems

An ecosystem is generally regarded as a self-sufficient unit and a separate entity. However, it never operates in isolation. Boundaries between one ecosystem and another are indistinct and overlapping and all ecosystems on the earth are joined together to form a single global ecosystem known as biosphere, Some exchange of materials and energy always occurs between different ecosystems through geological, climatic, or biological processes.

“what is ecosystem class 12 “

NEET Biology Notes For Ecosystem Productivity Of Ecosystem

  • Coral reefs, tropical rain forests, and sugarcane are most productive.
  • Deserts and deep sea ecosystems are least productive.

Energy

An ecosystem is maintained by the flow of energy derived from the sun. Energy trapped by plants varies from ecosystem to ecosystem energy absorption at different levels.

NEET Biology Ecosystem Energy

  • Gross primary productivity (GPP): It is the rate of organic matter synthesized by producers per unit area per unit time.
  • Net primary productivity (NPP): It is the rate of organic matter built up or stored by producers in their bodies per unit time and area. Net productivity is equal to gross primary productivity minus loss due to respi- ration and other reasons.
    NPP = GPP- Respiratory loss
    The annual NPP of the whole biosphere is approximately 170 billion ton (dry wt.) of organic matter. Despite occupying about 70% of the surface, the productivity of oceans is only 55 billion ton.
  • Secondary productivity: The rate of increase in energy containing organic matter or biomass by heterotrophs or consumers per unit time and area is known as secondary productivity.
  • Community productivity: It is the rate of net synthesis of built-up of organic matter by a community per unit time and area.
  • Ecological efficiency/trophic level efficiency: The percentage of energy converted into biomass by a higher trophic level over the energy of food resources available at the lower trophic level is called ecological efficiency.
  • Photosynthetic efficiency = Gross primary productivity/Incident total solar radiation
  • Net production efficiency = Net primary productivity/Gross primary productivity x 100

NEET Biology Notes For Ecosystem Decomposition

Decomposition is the process of physical and chemical breakdown of complex organic remains by organisms called decomposers, so as to produce inorganic raw materials (CO2, H2O, minerals, etc.) for recycling. The major site for decomposition is the upper layer of soil in terrestrial habitats and the bottom of water bodies. Freshly deposited organic matter constitutes raw material and is called litter. Detritus is degrading dead organic matter.

It is differentiated into above-ground and below-ground detritus. Above-ground detritus consists of dried plant parts (leaves, twigs, bark, and flowers), excreta, and dead remains of animals. Below-ground detritus is also called root detritus because it is mainly composed of dead roots. Underground organisms and their excreta also form a pan of below-ground detritus.

NEET Biology Notes For Ecosystem Decomposition Processes

Three types of processes occur simultaneously during the decomposition of detritus, viz. fragmentation, leaching, and catabolism.

  • Fragmentation of detritus: Small invertebrate animals, called detrivores, feed on detritus, e.g., earthworms and termites. They bring about its frag- mentation. A part of detritus eaten by detrivores comes out in a highly pulverized state in their feces. Due to fragmentation during eating and pulverization in digestive tracts, detritus is changed into fine particles which have a large surface area.
  • Leaching: Parts of soluble substances present in the fragmented and decomposing detritus (e.g., sugars and inorganic nutrients) get leached to the upper layers of soil by percolating water.
  • Catabolism: It is carried out by saprotrophic bacteria and fungi. They secrete digestive enzymes over the fragmented detritus. The enzymes change complex organic compounds into simple compounds. Inorganic substances are also released in the process.

“ecosystem and energy flow class 12 notes “

The rate of catabolic action or breakdown of different complex substances is different. This differential decomposition produces two substances: humus and inorganic nutrients in processes, respectively, called humification and mineralization, which occurs in soil.

  • Humification: It is the process of particle decomposition of detritus to form humus. Humus is a dark-colored amorphous partially decomposed organic matter rich in cellulose, lignin, tannins, resin, etc., because of its highly resistant nature. It is slightly acidic, colloidal, and functions as a reservoir of nutrients.
  • Mineralization: It is the release of inorganic substances (e.g., CO2, H2O, and minerals) from organic matter during the process of decomposition. These are formed along with simple and soluble organic substances when digestive enzymes are poured over organic matter by saprotrophic microbes.

NEET Biology Notes For Ecosystem Factors Affecting Decomposition

The rate of decomposition of detritus is controlled by a number of factors.

  • Chemical nature of detritus: The decomposition of detritus is slow if it contains lignin, chitin, tannins (phenolics), and cellulose. It is rapid if detritus possesses more of nitrogenous compounds (such as proteins and nucleic acids) and reserves carbohydrates.
  • Soil pH: Detrivores are fewer in acidic soils. Microbial activity is also low in such soils. Therefore, the rate of decomposition of organic matter is slow in acidic soils. Partially decomposed organic matter piles up over such soils. Detrivores are abundant in neutral and slightly alkaline soils while decomposer microbes are rich in neutral and slightly acidic soils.
  • Temperature: At a temperature of more than 25°C, decomposers are very active in soils having good moisture and aeration. In humid tropical regions, it does not take more than 3-4 months for complete decomposition of detritus. However, under low temperature conditions (> 100°C) of soils, the rate of decomposition is very slow even if moisture and aeration are optimum.
  • Moisture: Optimum moisture helps in quicker decomposition of detritus. Reduction in moisture reduces the rate of decomposition in areas of prolonged dryness such as tropical deserts where otherwise the temperature is quite high. Excessive moisture also impedes decomposition.
  • Aeration: It is required for the activity of decomposers and detrivores. A reduced aeration will slow down the process of decomposition.

“ecosystem notes class 12 pdf “

NEET Biology Notes For Ecosystem Energy Flow

  • Food chain: It is a sequence of living organisms in which one organism consumes another due to interdependence.
  • Key industry animals: These are herbivores who convert plant matter into animal matter.
    There are three types of industry animals:

    • Grazing food chain (GFC)/predator food chain major in aquatic ecosystems
    • Detritus food chain-major in terrestrial ecosystems
    • Parasitic food chain
  • DFC
    • Source of energy is detritus not sun.
    • It is composed of a long chain of detritus-eating organisms (detritivores).
    • In some ecosystems (e.g., tropical rain forests), more energy flows in this chain than in the GFC.
  • Food web: The interconnected food chains operating in an ecosystem are called food webs. It is, thus, a collection of food chains.
  • Standing state or standing quality: It is the amount of inorganic substances present in an ecosystem per unit area at a given time.
  • Standing crop: It is the amount of living material present in different trophic levels at a given time. It is commonly expressed as the number of organisms per unit area.

NEET Biology Notes For Ecosystem Ecological Pyramids

Ecological pyramids (Eltonian pyramids) were developed by Charles Elion in 1927. They are graphical representation of dif- ferent ecological parameters. In the pyramid, producers form the base and top carnivores the tip. The pyramid can be upright, inverted, or spindle shaped. These are of three types:

  • Pyramid of number: Upright for grassland and pond and inverted for parasitic ecosystem.
  • Pyramid of biomass: Upright for terrestrial habitats and inverted for aquatic habitats.
  • Pyramid of energy: Always upright.

NEET Biology Notes For Ecosystem Ecological Succession (By Hult)

Every community undergoes a series of changes until a group of organisms is established which can live and reproduce most successfully in the area. This is called biotic succession. A biotic community normally undergoes continuous changes. The interactions among organisms in a community collectively constitute biotic factors; these influence the structure, composition, and function of a community.

Generally, a definite and orderly sequence of communities gradually appears in an area over a period of time. The first community which appears on an area is called pioneer community. A specific sequence of development of a community is related to a particular set of physical and chemical conditions. This is known as a sere, and is composed of a number of biotic communities replacing each other in the course of time called seral communities. The last community is called climax or a climatic climax (as it mostly depends upon climate).

  • Primary succession: It occurs on biologically sterile area which has no record of any previous vegetation. The conditions are extreme and it takes very long time (1000 years) to complete, i.e., establishing climax community, e.g., newly created pond.
  • Secondary succession: It occurs on an area that was previously occupied by vegetation and was later destroyed by fire, deforestation, over-grazing, volcanic eruptions, and floods. Humus is already present and environment is not so hostile. Therefore, it takes lesser time.
  • Autogenic and allogenic succession: When a community replaces the other due to the modification of the environment by the community itself, the succession is called autogenic. On the contrary, when a community replaces the other largely due to the forces other than the effects of communities on the environment, the succession is said to be allogenic.
  • Autotrophic and heterotrophic succession: Autotrophic succession is characterized by early dominance of autotrophic organisms and begins in predominantly inorganic environment. On the contrary, heterotrophic succession is characterized by early dominance of heterotrophs and begins in a predominantly organic environment.

NEET Biology Notes For Ecosystem Process of Succession

Major steps in a primary autotrophic succession are as follows:

  • Nudation: An area is exposed.
  • Migration: The process of dispersal of seeds, spores, and other structures of propagation of the species to bare area is known as migration.
  • Germination: It occurs when conditions are favorable.
  • Ecesis: Successful germination of propagules and their establishment in a bare area is known as ecesis.
  • Colonization and aggregation: After ecesis, the individuals of the species increase in number as a result of reproduction.
  • Competition and co-action: Due to limited resources, species show both inter and intraspecific competition. This results in the elimination of unsuitable and weaker plants.
  • Invasion: Various other types of plants try to establish in the spaces left by the elimination of plants due to competition.
  • Reaction: The newly arrived plants interrupt with the existing ones. As a result of reaction, the environment is modified and becomes unsuitable for the existing community which sooner or later is replaced by another community.
  • Stabilization: It is the process when the final climax community becomes more or less stabilized for a longer period of time and can maintain itself in equilibrium with the climate of the area. As compared to the seral stage community, the climax community has larger size of individuals, complex organization, complex food chains and food webs, more efficient energy use, and more nutrient conservation.

NEET Biology Notes For Ecosystem Major Trends During Succession

  • There is an increase in structural complexity.
  • Diversity of species tends to increase.
  • Biomass and standing crop increase.
  • There is a decrease in net community production. There is an increase in non-living matter.
  • Food chain relationship becomes complex.
  • Niche becomes specific and narrower.
  • Energy use and nutrient conservation efficiency increase.
  • Stability increases.

NEET Biology Notes For Ecosystem Contents of Ecological Succession

  • Lithosere (succession on desert/rock):
    • Lichen stage: Wind borne lichen propagules settle on the wet rock surface soon after rain or heavy dew. They develop attaching structure rhizenes. The pioneer lichens are usually crustose lichens, e.g., Graphis, Rhizocarpon, etc. They secrete lichen acids and carbonic acid. The acids slowly corrode rock surface and release minerals required for the proper growth of larger lichens, i.e., foliose lichens, e.g., Parmelia.
    • Moss stage: Foliose lichens growing on rocks make the conditions favorable for the growth of hardy mosses. Ultimately, the spot becomes suitable for invasion by the next stage (e.g., Hypnum and Bryum).
    • Annual grass stage: The mat formed by mosses on the partially fragmented rock becomes sufficiently moist during the rainy season for the germination of seeds of annual grasses and other hardy herbs, e.g., Aristida, Poa, and Eleusine.
    • Perennial grass stage: Annual grasses are replaced by perennial grasses due to increased moisture and soil in the rock crevices. The perennial grasses have runners and rhizomes which rapidly spread the grasses, e.g., Cymbopogon and Heteropogon.
    • Shrub stage: Seeds and rhizomes of xerophytic shrubs invade the area occupied by perennial grasses, e.g., Zizyphus, Capparis, Rhus, and Rubus. Shrubs are larger and their roots reach greater depth causing further cracks in the rocky substratum and, hence, helping in more soil formation.
    • Climax community: Several hardy and light demanding trees grow in the area occupied by shrubs. Slowly the environment becomes more moist and shadier so that plants. of climax community spread in the area. The type of climax community depends upon the climate. Therefore, it is also called climatic climax community.
  • Hydrosere (succession on pond):
    • Plankton stage: It is the pioneer stage of hydrosere. Planktons reach the water body through wind or animals. The first to appear are minute autotrophic organisms called phytoplankton, e.g., diatoms; green flagellates; single-celled, colonial, or filamentous green algae; as well as blue green algae. They multiply rapidly. Soon a balance is created by the appearance of zooplankton which feeds on ohytoplankton.
    • Submerged stage: The bottom lined by soft mud having organic matter is favorable for the growth of submerged plants such as Hydrilla, Potamogeton, and Najas.
    • Floating stage: Floating leaved anchored plants (e.g., Nymphaea, Nelumbo, and Nuphar) appear where water becomes shallow. These plants have subterranean stems like rhizome and tuber. The plants make the water rich in mineral and organic matter. It becomes suitable for the growth of free floating plants such as Lemna, Spirodela, Wolffia, Azolla, and Eichhornia.
    • Reed swamp stage: Amphibious plants grow when the water body becomes shallow (0.3-1 m). Examples are Phragmites, Typha, Scirpus, and Sagittaria. The plants of swamp stage transpire nice quantities of water.
    • Sedge or marsh meadow stage: The shores built up in reed swamp stage are invaded by Carex (sedge); Cyperus; Juncus; grasses such as Themeda; and herbs such as Campanula, Caltha, and Polygonum. The plants transpire rapidly and add abundant humus.
    • Scrub/woodland stage: The periphery of sedge meadow stage is invaded by some rhizome bear- ing shrubby plants which can tolerate bright sunlight as well as water logged conditions, e.g., Cornus (bogwood), Cephalanthus (button brush); etc. They invite invasion by trees capable of bearing bright sunlight and water logging, e.g., Populus (cottonwood) and Alnus (alder).
    • Climax forest: New trees invade the area. They have shade-loving seed plants. These trees grow to greater heights.

NEET Biology Notes For Ecosystem Nutrient Cycling

Nutrient cycling is of three types:

  • Gaseous: Examples are carbon (absorbed as CO2), nitrogen, oxygen (as vapors), and main reservoir pool (as atmosphere or water).
  • Sedimentary: Biogenetic materials are nongaseous and have lithosphere as the main reservoir pool. Examples are P, Ca, and Mg. Both sedimentary and gaseous phases occur in case of sulfur.
  • Mixed: Nutrients have both gaseous and nongaseous states, e.g., sulfur. Tundra consists of plains with snow, ice, and frozen soil (permafrost).

“class 12 bio ecosystem notes “

NEET Biology Notes For Ecosystem Aquatic Biomes

Five general categories of aquatic ecosystems are usually recognized:

  • Marine pelagic areas within the water mass of oceans with water of high salinity
  • Marine benthic areas on the ocean floor with water of high salinity
  • Estuaries, bodies, or oceanic water near the mouths of freshwater rivers with intermediate salinity
  • Freshwater lotic with flowing water of low salinity Freshwater lentic with non-flowing water of low salinity

Marine Biome

The marine environment is characterized by its high concentration of salt (about 3.5% in open sea) and mineral ions (mostly sodium and chloride followed by sulfur, magnesium, and calcium). All ocean basins are roughly of the shape of a wash basin (or an inverted hat).

From the coastline, a gradually sloping region extends to about 160 km into the sea. This zone, with a depth of 8-200 m, is called the continental shelf. The angle of the slope then abruptly steepens to form the continental slope which levels off into a more or less horizontal expanse forming the ocean floor.

The vertical zones of the ocean are determined on the basis of availability of light for photosynthesis.

  • The well-lit upper 200 m forms the photic or euphotic zone.
  • The next zone up to the depth 200-2000 m gets less light which is insufficient for photosynthesis and forms disphotic zone.
  • Below 2000 m is the area of perpetual darkness-the abyssal zone/dark zone.

NEET Biology Notes For Ecosystem Freshwater Biomes (Lakes and Ponds)

Freshwater biomes are stationary water bodies. Ponds are small and shallow. Lakes are larger and deeper. Lakes develop in na- ture due to the following reasons:

  • Glaciation
  • Natural or man-made depressions
  • Oxbow lakes which develop from the main stream of a river

Depending upon productivity, lakes are of three types:

  • Oligotrophic lakes: These lakes are deep with rocky steep sides and with less circulation of nutrients. They have little biota but are rich in green algae. Brackish lakes are oligotrophic and also occur in arid areas, e.g., Sambhar Lake in Rajasthan.
  • Eutrophic lakes: These lakes are rich in biota and have quick circulation of nutrients. These are shallow with abundant blue green algae, e.g., Dal Lake in Kashmir.
  • Dystrophic lakes: These lakes are rich in humic acid and are less productive.

NEET Biology Notes For Ecosystem Life Forms

Raunkiaer (1934) has distinguished plants into five forms on the basis of size, shape, branching, crown, life span, and perennation.

  • Phanerophytes: Perennial herbs, shrubs and trees, epiphytes, succulents, lianas, etc., where perennating buds occur at a height of 10 cm or more above the ground level.
  • Chemaephytes: Small plants of cold areas where perennating buds or shoot apices lie at or above the ground level.
  • Hemieryptophytes: Perennating structures occur at the ground level. Aerial shoots die with the onset of winter, e.g., rosette plants.
  • Cryptophytes: Perennial plants with underground storage parts. These are of different types such as
    • Geophytes: These Subterranean perennating structure (root, root tuber, bulb, stem tuber, rhizome, corm).
    • Halophytes (marshy plants): Perennating structure embedded in mud.
    • Hydrophytes (aquatic plants)
    • Thorophytes: Plants which perennate in the form of seeds.

NEET Biology Notes For Ecosystem Services

The products of ecosystem processes are called ecosystern services, e.g., healthy forest ecosystems purify air and water, mitigate droughts and floods, cycle nutrients, generate fertile soils, provide wildlife habitat, maintain biodiversity, pollinate crops, provide storage site for carbon, and also provide aesthetic, cultural, and spiritual values.

Researchers like Robert Constanza et. al. have put an average price tag of US$ 33 trillion a year on these fundamental ecological services (i.e., nearly twice the value of a global GNP – US$ 18 trillion).

Out of total cost, soil formation accounts for about 50%, recreation and nutrient cycling less than 10% each, and climate regulation and habitat for wildlife account for about 6% each.

NEET Biology Notes For Ecosystem Services Question And Answers

In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R).

  1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark (1).
  2. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
  3. If Assertion is true but Reason is false, then mark (3).
  4. If both Assertion and Reason are false, then mark (4).

Question 1. Assertion: Agriculture and aquacultures are man-maintained ecosystems.

Reason: All biotic and abiotic factors are managed by humans in these ecosystems.

Answer. 1. In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R).

Question 2. Assertion: Warm and moist environment can enhance the rate of decomposition.

Reason: Warm and moist climate leads to create anaerobic condition which promotes decomposition.

Answer. 3. If Assertion is true but Reason is false, then mark (3).

Question 3. Assertion: Detritus food chain begins with decomposers.

Reason: Detrivores, like fungi and bacteria, are major decomposers in such food chains.

Answer. 3. If Assertion is true but Reason is false, then mark (3).

Question 4. Assertion: Ecological pyramids cannot explain all vital functions of any ecosystem.

Reason: Pyramids actually do not explain the role of organisms working at more than one trophic level.

Answer. 2. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark (1).

Question 5. Assertion: Successional process starts only in those areas where no living organisms ever existed.

Reason: These areas are not supported by physical environmental conditions.

Answer. 4. If both Assertion and Reason are false, then mark (4)

NEET Biology Multiple Choice Questions – Organisms And Populations

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NEET Biology Organisms And Populations Multiple Choice Questions

Question 1. The term “ecology” was given by

  1. Odum
  2. Haeckel
  3. Tansley
  4. R. Misra

Answer. 2. Haeckel

Question 2. A large regional unit characterized by a specific flora and fauna is called

  1. Biome
  2. Biosphere
  3. Ecosystem
  4. Landscape

Answer. 1. Biome

Question 3. A group of individuals living in a particular geographical area at a particular time is called

  1. Local population
  2. Deme
  3. Community
  4. Both (1) and (2)

Answer. 4. Both (1) and (2)

” ncert organism and population “

Question 4. The functional role and status of a species in a community is called

  1. Performance
  2. Ecological niche.
  3. Tolerance
  4. Organization

Answer. 2. Ecological niche.

Question 5. Organisms living in arctic and antarctic climatic zones are called

  1. Megatherms
  2. Mesotherms
  3. Microtherms
  4. Hekistotherms

Answer. 4. Hekistotherms

Question 6. The two climatic factors which largely determine the vegetation and soil types are

  1. Temperature and precipitation
  2. Temperature and light
  3. Light and precipitation
  4. Light and weather

Answer. 1. Temperature and precipitation

Question 7. Chylorhizy is found in

  1. Opuntia
  2. Euphorbia
  3. Asparagus
  4. Aloe

Answer. 3. Asparagus

Question 8. The value of lapse rate is

  1. 1.6°C per 100 m elevation
  2. 6.5°C per 100 m elevation
  3. 6.5°C per 1000 m elevation
  4. 6.5°C per 10 m elevation

Answer. 3. 6.5°C per 1000 m elevation

Question 9. Solar constant is _____________ cal cm2/mm.

  1. 2
  2. 4
  3. 6
  4. 8

Answer. 1. 2

Question 10. The most harmful radiation is

  1. UV-A
  2. UV-B
  3. UU-C
  4. All are equally harmful

Answer. 2. UV-B

Question 11. The timing of seasonal activity of plants in relation to environmental conditions is called

  1. Physiognomy
  2. Phenology
  3. Stratification
  4. Agrostology

Answer. 2. Phenology

Question 12. The bottom zone in a lake is called

  1. Limnetic
  2. Profundal
  3. Benthic
  4. Littoral

Answer. 3. Benthic

Question 13. The number of temperature zones in a summer lake is

  1. 2
  2. 3
  3. 4
  4. 5

Answer. 2. 3

Question 14. In meromictic lakes, the number of turnovers of water per year is

  1. 1
  2. 2
  3. Many
  4. Zero

Answer. 4. Zero

Question 15. The turnover in a lake in spring and autumn results in

  1. Free mixing of O, and nutrients
  2. Algal bloom
  3. Temperature inversion
  4. Both (1) and (2)

Answer. 4. Both (1) and (2)

Question 16. Shorter body extremities in animals living in colder climate is explained by

  1. Allen’s rule
  2. Bergman’s rule
  3. Gloger’s rule
  4. Jordan’s rule

Answer. 1. Allen’s rule

Question 17. Permanent wilting percentage (PWP) is the highest in

  1. Silt
  2. Sandy soil
  3. Loam
  4. Clay soil

Answer. 2. Sandy soil

Question 18. In soil profile, the zone of eluviation is

  1. O-zone
  2. A-zone
  3. B-zone
  4. C-zone

Answer. 2. A-zone

Question 19. A good soil is that which

  1. Allows little water to enter in it
  2. Allows extra water to percolate slowly
  3. Holds water entering it
  4. Allows water to pass through it quickly

Answer. 2. Allows extra water to percolate slowly

Question 20. The size of clay particles is

  1. Between 0.00002 and 0.02 mm
  2. Less than 0.002 mm
  3. 0.5-1.0 mm
  4. 0.02-0.2 mm

Answer. 2. Less than 0.002 mm

Question 21. Alluvial soils are mostly found in

  1. Northern India
  2. Eastern India
  3. Southern India
  4. Ganges and Yamuna plains

Answer. 4. Ganges and Yamuna plains

Question 22. Which of the following soils shows cracks and shrinks most when it dries?

  1. Porous soil
  2. Clay soil
  3. Loam soil
  4. Sandy soil

Answer. 2. Clay soil

Question 23. Soil porosity is the maximum in

  1. Sandy soil
  2. Clay soil
  3. Silt
  4. Loan

Answer. 2. Clay soil

Question 24. Mull humus is characterized by

  1. Nutrient deficiency
  2. Layered composition
  3. Ca+2 deficiency
  4. Rich bacterial growth

Answer. 4. Rich bacterial growth

Question 25. What is the percentage of air in the soil?

  1. 50
  2. 10
  3. 45
  4. 25

Answer. 4. 25

Question 26. The law of tolerance was given by

  1. Shelford
  2. Haeckel
  3. J. Grinnel
  4. Gause

Answer. 1. Shelford

Question 27. The critical minimum and maximum value of an environmental factor is called

  1. Limiting factor
  2. Law of minimum
  3. Limits of tolerance
  4. Carrying capacity

Answer. 3. Limits of tolerance

Question 28. Weeds are usually

  1. Eurytopic
  2. Stenotopic
  3. Amensal
  4. Smoother crops

Answer. 1. Eurytopic

Question 29. A genotypically adapted local population is called

  1. Ecad
  2. Ecotype
  3. Ecocline
  4. Ecotone

Answer. 2. Ecotype

Question 30. Phreatophytes are/have

  1. True xerophytes
  2. Deep roots
  3. Indicator plants
  4. All of these

Answer. 4. All of these

Question 31. Chemicals which provide physiological adaptations to plants against high temperature and saline conditions are

  1. Chaperonins
  2. Proline, glycerol
  3. Betaine, sorbital
  4. All of these

Answer. 4. All of these

Question 32. Vivipary and prop roots are the characteristics of

  1. Coastal plants
  2. Hot desert plants
  3. Mangrove plants
  4. Cold desert plants

Answer. 3. Mangrove plants

Question 33. Which of the following characters does not characterize a hydrophyte?

  1. Abundant air space and air chambers
  2. Abundant xylem and sclerenchyma
  3. Leaves having stomata only on upper side or none
  4. Poor development of roots

Answer. 2. Abundant xylem and sclerenchyma

Question 34. Plants are killed in the winter by frost

  1. Because of desiccation and mechanical damages to the tissues
  2. Because no photosynthesis takes place at such low temperature
  3. Because respiration ceases at such low temperature
  4. Because there is no transpiration

Answer. 1. Because of desiccation and mechanical damages to the tissues

Question 35. Ephemerals are xeropytes that are

  1. Drought enduring
  2. Drought escaping
  3. Drought resisting
  4. None of these

Answer. 2. Drought escaping

Question 36. The factors which include the form, surface, and behavior of the earth with special reference to slopes, mountains, and valleys are called

  1. Edaphic factors
  2. Biotic factors
  3. Climatic factors
  4. Topographic factors

Answer. 4. Topographic factors

Question 37. The capacity to blend with surroundings is called

  1. Hibernation
  2. Mimicry
  3. Camouflage
  4. Aestivation

Answer. 3. Camouflage

Question 38. A behavioral strategy of adaptation called echolocation is found in

  1. Bats
  2. Monarch butterfly
  3. Praying mantis
  4. Arctic tern

Answer. 1. Bats

Question 39. Natality under actual conditions is called

  1. Biotic potential
  2. Maximum natality
  3. Ecological natality
  4. Reproductive potential

Answer. 3. Ecological natality

Question 40. Vital index of a population is

  1. (B/D) × 100
  2. B-D
  3. (D/B) × 100
  4. B+D

Answer. 1. (B/D) × 100

Question 41. An urn-shaped population-age pyramid represents

  1. Growing population
  2. Static population
  3. Declining population
  4. Threatened population

Answer. 3. Declining population

“ncert organisms and population “

Question 42. The ability of an environment to support a population is called its

  1. Biotic potential
  2. Purifying capacity
  3. Carrying capacity
  4. Environmental resistance

Answer. 3. Carrying capacity

Question 43. In the equation for S-shaped population growth, r represents

  1. Carrying capacity
  2. Environmental resistance
  3. Biotic potential
  4. Population size

Answer. 3. Biotic potential

Question 44. Which of the following statements is not true for J-shaped growth curve?

  1. Exponential phase is prolonged.
  2. Population never grows beyond carrying capacity.
  3. Population crash occurs.
  4. Population seldom reaches equilibrium.

Answer. 2. Population never grows beyond carrying capacity.

Question 45. In the formula of population growth, rN represents the

  1. Environmental resistance
  2. Reproductive potential
  3. Growth rate
  4. Carrying capacity

Answer. 1. Environmental resistance

Question 46. Which statement is not related to S-shaped population curve?

  1. Environmental resistance suddenly becomes effective.
  2. Exponential phase is followed by decline phase.
  3. Mass mortality and population crash occurs.
  4. Both (1) and (3).

Answer. 4. Both (1) and (3).

Question 47. The periodic departure and return is known as

  1. Migration
  2. Immigration
  3. Emigration
  4. Mutation

Answer. 1. Migration

Question 48. When an animal group is centered around a dominant female, it is called

  1. Patriarchy
  2. Matriarchy
  3. Swarm
  4. Flock

Answer. 2. Matriarchy

Question 49. Altruistic behavior is not found in

  1. White ants
  2. Spotted deer
  3. Honey bees
  4. Bitch

Answer. 4. Bitch

Question 50. Territory is defended against

  1. Predator
  2. Any intruder
  3. Intruder of another species
  4. Intruder of the same species

Answer. 4. Intruder of the same species

Question 51. The inability of different organisms to interbreed is called

  1. Sterility
  2. Parasitism
  3. Reproductive isolation.
  4. Monogamy

Answer. 3. Reproductive isolation.

Question 52. The increased number and density of species in the region of ecotone is called

  1. Edge effect
  2. Sympatric speciation
  3. Dominance
  4. Abundance

Answer. 1. Edge effect

Question 53. Which of the following associations is not an example of symbiosis?

  1. Lichen
  2. Mycorrhiza
  3. Root nodules
  4. Epiphytes

Answer. 4. Epiphytes

Question 54. Which is not an effect of competition?

  1. Regulation of population size
  2. Generalization of niche
  3. Establishment of social hierarchy
  4. Help in speciation

Answer. 2. Generalization of niche

Question 55. Competitive exclusion principle was given by

  1. J. Grinnel
  2. Gause
  3. Lindeman
  4. Bates

Answer. 2. Gause

Question 56. Which of the following shows biological antagonism or allelopathy?

  1. Amensalism
  2. Proto-cooperation
  3. Competition
  4. Parasitism

Answer. 1. Amensalism

Question 57. The interaction between two living organisms of different species which is beneficial to both but is not obligatory because they can live without each other is known as

  1. Proto-cooperation
  2. Mutualism or symbiosis
  3. Commensalism
  4. Amensalism

Answer. 1. Proto-cooperation

Question 58. Find the odd one out:

  1. Lianas in tropical rain forest
  2. E. coli in large intestine of man
  3. Pilot fish remora and shark
  4. Rafflesia on the roots of a forest tree

Answer. 4. Rafflesia on the roots of a forest tree

Question 59. Find the odd one out:

  1. Mating
  2. Competition
  3. Aggregation
  4. Altruism

Answer. 2. Competition

Question 60. A toxic chemical against nematode is secreted by

  1. Tagetes
  2. Black walnut
  3. Penicillium
  4. Grevillea robusta

Answer. 1. Tagetes

Question 61. Which one of the following is a hemiparasite?

  1. Viscum
  2. Cuscuta
  3. Rafflesia
  4. None of these

Answer. 1. Viscum

Question 62. Competition for food, light, and space is most severe between two

  1. Distantly related species growing in different habitats
  2. Distantly related species growing in the same habitat
  3. Closely related species growing in different habitats
  4. Closely related species growing in the same area

Answer. 4. Closely related species growing in the same area

Question 63. The species which are present in large numbers and have large size are called

  1. Ecological equivalent
  2. Ecological dominants
  3. Link species
  4. Keystone species

Answer. 2. Ecological dominants

Question 64. The transition zone between two communities is called

  1. Ecocline
  2. Ecotone
  3. Buffer zone
  4. Thermocline

Answer. 2. Ecotone

Question 65. Which of the following is a keystone species?

  1. Fig
  2. Deer
  3. Mycorrhiza
  4. Pollinator

Answer. 1. Fig

Question 66. Find the odd one out:

  1. Viceroy butterfly resembling monarch butterfly
  2. Stick insect resembling thin, dry branches
  3. Caterpillars of geometrid moth resembling small branches
  4. Leaf insect resembling green leaf

Answer. 1. Viceroy butterfly resembling monarch butterfly

Question 67. Mimicry is a device for

  1. Concealing from predator
  2. Concealing from prey
  3. Both (1) and (2)
  4. Becoming conspicuous

Answer. 3. Both (1) and (2)

Question 68. Match the following columns:

Column 1                                Column 2

a. Oxylophytes                (1) Calcium-rich soils

b. Eremophytes              (2) Waste land

c. Chrysophytes              (3) Deserts, steppes

d. Calciphytes                 (4) Acidic soils

  1. a (1), b (2), c (3), d (4)
  2. a (1), b (3), c (4), d (2)
  3. a (4), b (3), c (2), d (1)
  4. a (4), b (3), c (1), d (2)

Answer. 3. a (4), b (3), c (2), d (1)

“population attributes “

Question 69. Which of the following statements is correct?

  1. Two species within a given community can have exactly the same niche.
  2. Two species within a given community cannot have exactly the same niche.
  3. Two species can live permanently together
  4. Both (2) and (3).

Answer. 4. Both (2) and (3).

Question 70. Biotic potential refers to

  1. Increase of population under optimum conditions
  2. Increase of population under given conditions
  3. Increase of population under natural conditions
  4. Increase of population under stress conditions

Answer. 1. Increase of population under optimum conditions

Question 71. Edge effect refers to

  1. Occurrence of ecophenes and ecotypes in a community
  2. Low diversity of organisms in ecotone
  3. High diversity of organisms in ecotone
  4. Defense of territories by organisms

Answer. 3. High diversity of organisms in ecotone

Question 72. In India, tropical rain forests are generally found in

  1. Western Ghats
  2. North-eastern Himalayas
  3. Gangetic Plains in India
  4. Both (1) and (2)

Answer. 4. Both (1) and (2)

Question 73. The forests which show contrasting seasonal aspects are

  1. Tropical rain forests
  2. Temperate broad-leaf forests
  3. Tropical deciduous forests
  4. Temperate needle-leaf forests

Answer. 3. Tropical deciduous forests

Question 74. Which is not a characteristic feature of grassland?

  1. Extensive root system
  2. High productivity
  3. Periodic fire
  4. Developed stratification

Answer. 4. Developed stratification

Question 75. Most of the deserts are distributed between

  1. 150-350 latitude
  2. 400-600 latitude
  3. 600-800 latitude
  4. Only in Southern Hemisphere

Answer. 1. 150-350 latitude

Question 76. A biome having a well-developed grass cover interspersed with scattered trees is a

  1. Grassland
  2. Savannah
  3. Desert
  4. Temperate forest

Answer. 2. Savannah

Question 77. The taiga region is also known as

  1. Deciduous forest
  2. Tropical rain forest
  3. Northern conifer forest
  4. Tropical savannah

Answer. 3. Northern conifer forest

Question 78. The grassland vegetation of Africa is known as

  1. Prairies
  2. Pampas
  3. Steppes
  4. Veldts

Answer. 4. Veldts

Question 79. Arctic tundra is

  1. Highest latitudinal biome
  2. Located in rain shadow
  3. Characterized by Capparis and Prosopis species
  4. Highest altitudinal biome

Answer. 1. Highest latitudinal biome

Question 80. Ethology is the study of

  1. Behaviour of animals
  2. Past life of organism
  3. Disease causing pathogens
  4. None of these

Answer. 1. Behaviour of animals

Question 81. Humus is

  1. Dead and decayed organic matter
  2. Living matter
  3. Fertilizers
  4. Living animal/plants/microbes

Answer. 1. Dead and decayed organic matter

Question 82. Name the famous plant ecologist:

  1. Jagdish Chandra Bose
  2. Birbal Shani
  3. Ramdeva Misra
  4. Charles Darwin

Answer. 3. Ramdeva Misra

Question 83. The correct percentage of CO, in atmosphere is

  1. 0.03%
  2. 0.3%
  3. 1%
  4. 1.1%

Answer. 1. 0.03%

Question 84. In aquatic environment, microscopic animals and plants are collectively known as

  1. Commensals
  2. Herbivores
  3. Fauna and Flora
  4. Planktons

Answer. 4. Planktons

Question 85. June 5 is

  1. World Environment Day
  2. Wold AIDS Day
  3. World Womens Day
  4. World Polio Day

Answer. 1. World Environment Day

Question 86. Plants developing in dry condition are

  1. Xerophytes
  2. Mesophytes
  3. Lithophytes
  4. Hydrophytes

Answer. 1.Xerophytes

Question 87. Soil carried by gravity is

  1. Alluvial
  2. Colluvial
  3. Elluvial
  4. Glacial

Answer. 2. Colluvial

Question 88. Velamen tissue is found in

  1. Mesophytes
  2. Epiphytes
  3. Hydrophytes
  4. Xerophytes

Answer. 2. Epiphytes

Question 89. Pneumatophores are characteristic feature of

  1. Hydrilla
  2. Rhizophora
  3. Typha
  4. None of these

Answer. 2. Rhizophora

Question 90. Factors relating to form and behavior of the earth’s surface are called

  1. Edaphic
  2. Topographic
  3. Climatic
  4. Biotic

Answer. 2. Topographic

Question 91. Aerenchyma is helpful in plants by

  1. Providing buoyancy in hydrophytes
  2. Absorption in stilt roots
  3. Giving mechanical strength to plants
  4. Giving flexibility to plants

Answer. 1. Providing buoyancy in hydrophytes

Question 92. Plants growing in saline soil are called

  1. Xerophyte
  2. Hydrophyte
  3. Halophyte
  4. Heliophyte

Answer. 3. Halophyte

Question 93. Which one of the following is a well-developed tissue present in hydrophytes?

  1. Aerenchyma
  2. Collenchyma
  3. Stomata
  4. Root system

Answer. 1. Aerenchyma

Question 94. Penumetophores are found in

  1. Orchid
  2. Piper
  3. Ficus
  4. Rhizophora

Answer. 4. Rhizophora

Question 95. The term “autecology” refers to the study of

  1. Plant community
  2. Individual organism
  3. Environment
  4. Soil form

Answer. 2. Individual organism

Question 96. Autoecology refers to

  1. Plant ecology
  2. Animal ecology
  3. Ecological study of individual species
  4. Ecological study of group of species, which is grown together

Answer. 3. Ecological study of individual species

Question 97. Which part of the pond ecosystem does not get affected by temperature?

  1. Epilimnion
  2. Metalimnion
  3. Hypolimnion
  4. All

Answer. 3. Hypolimnion

Question 98. Root cap is absent in

  1. Mesophytes
  2. Hydrophytes
  3. Epiphytes
  4. Xerophytes

Answer. 2. Hydrophytes

Question 99. Which of the following have sunken stomata?

  1. Nerium
  2. Mangifera
  3. Hydrilla
  4. Zea mays

Answer. 1. Nerium

Question 100. Velamen and spongy tissue are found in

  1. Breathing roots
  2. Parasitic roots
  3. Tuberous roots
  4. Epiphytic roots

Answer. 4. Epiphytic roots

Question 101. Root cap is absent in

  1. Lithophytes
  2. Xerophytes
  3. Hydrophytes
  4. Mesophytes

Answer. 3. Hydrophytes

Question 102. Which of the following is the example of xerophytes?

  1. Brassica
  2. Cuscuta
  3. Capparis
  4. Hydrilla

Answer. 3. Capparis

Question 103. Organisms inhabiting a common environment belong to the same

  1. Species
  2. Genus
  3. Population
  4. Community

Answer. 4. Community

Question 104. Insectivorous plants usually survive in

  1. Water rich soil
  2. N2 deficient soil
  3. N2 rich soil
  4. Sugar deficient medium

Answer. 2. N2 deficient soil

Question 105. A group of two or more than two plants species is called

  1. Plant community
  2. Animal ecosystem
  3. Plant ecosystem
  4. Ecological niche

Answer. 1. Plant community

Question 106. Two vegetations of ecosystem are separated by

  1. Ecotone
  2. Ecoline
  3. Ecosytem
  4. Ecesis

Answer. 1. Ecotone

“organism and population neet pyq “

Question 107. In plant succession, the last community is called

  1. Ecotone
  2. Climax community
  3. Seral community
  4. Ecocystem

Answer. 2. Climax community

Question 108. In which of the following habitats the diurnal temperature of soil surface varies the most?

  1. Forest
  2. Desert
  3. Grassland
  4. Shrub land

Answer. 2. Desert

Question 109. People who have migrated from the planes to an area adjoining Rohtang Pass about 6 months back

  1. Are not physically fit to play games like football
  2. Suffer from altitude sickness with symptoms like nausea, fatigue, etc.
  3. Have the usual RBC count but their hemoglobin has very high binding affinity to O2
  4. Have more RBCs and their hemoglobin has a lower binding affinity to O2

Answer. 4. Have more RBCs and their hemoglobin has a lower binding affinity to O2

Question 110. Sacred groves are especially useful in

  1. Generating environmental awareness
  2. Preventing soil erosion
  3. Year-round flow of water in rivers
  4. Conserving rare and threatened species

Answer. 4. Conserving rare and threatened species

Question 111. The second stage of hydrosere is occupied by plants like

  1. Azolla
  2. Typha
  3. Salix
  4. Vallisneria

Answer. 4. Vallisneria

NEET Biology Notes – Organisms And Populations

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NEET Biology Notes PDF Free Download

NEET Biology Notes For Organisms And Populations

Habitat: A specific place (or locality) where an organism usually lives. It is a physical entity comprising the sum total of the abiotic factors to which a species or a group of species is exposed.

Ecological niche (J. Grinnel): It represents the functional role and status of a species in the environment. It represents habitat and trophic level of a species. No two species can have the same niche even if they are found in the same environment

Read and Learn More NEET Biology Notes

Population: A group of individuals of the same species in a well-defined geographical area which share or compete for similar resources and can potentially interbreed. Their study links ecology to genetics and evolution of a population.

Community: A number of interrelated populations of different species sharing a common environment.

Ecosystem: A functional unit of nature in which living organisms interact with one another and with their surrounding physical environment.

Biosphere: Any part of atmosphere inhabited by organisms.

Ecology deals with the various principles which govern the relationships between organisms and their environment. The term “ecology” was first used by Reiter in 1868. Ernst Haeckel (1886) first correctly defined ecology as the science dealing with reciprocal relationship of organisms and the external world. Warming (1895) employed this science for the study of plants. E.P. Odum (1963) defined it as the “study of structure and function of nature.”

Clarke, Warming, Weaver, Clements, Schimper, Dauben-malre, Raunkiaer, E.P. Odum, and H.T. Odum are some renowned ecologists. Prof. R. Misra is known as the “Father of Ecology in India.” Other famous Indian ecologists include G.S. Puri and S.C. Pandeya. Ecology gives a holistic perspective to biology.

 

NEET Biology Notes For Organisms And Populations Branches Of Ecology

  • Autecology: Ecology of individuals or species, essentially physiological ecology.
  • Synecology: Study of relationships between communities and environment.
  • Genecology: Study of ecological adaptations in relation to genetic variability.
  • Paleoecology: Study of relationship between organisms and environment in the past.
  • Applied ecology: Application of ecological concepts for human welfare.
  • Systems ecology: Interpretation of ecological concepts in terms of mathematical principles.

“population of organisms “

NEET Biology Notes For Organisms And Populations Organisms And Their Environment

Environment is the sum total of all external factors, substances, and conditions which influence organisms without becoming their constituent part. Environment is usually divided into two parts: physical environment and biotic environment.

Factors such as components, conditions, and forces of environment which have a direct and indirect effect on the form, functioning, behavior, survival, and reproduction of organisms are called environmental factors. These are of two types: abiotic and biotic. Abiotic factors are divisible into three categories: atmospheric, edaphic, and topographic. Atmospheric factors are light, temperature, water, and wind. Edaphic factors are related to soil. Topographic factors are abiotic or physical factors related to slope, altitude, etc., connected with the surface behavior of the earth. Biotic factors are influences produced by living organisms.

NEET Biology Notes For Organisms And Populations Biome (Major Ecosystems)

A biome is a large natural ecosystem which is distinct in its climatic conditions and has its specific group of climax plants and associated animals. Rainfall, temperature range, nature of soil, barriers, latitude, and altitude determine the nature and extent. of biomes.

The major biomes of India are as follows:

  • Tropical rain forests: In India, tropical rain forests are found mainly along Western Ghats and in north-eastern Himalayas. Dipterocarpus and hopea are the most common tree species in Indian rain forests. They show a 30-40 m tall canopy with four-five strata. Woody climbers and epiphytes grow profusely in these forests. The soil of such forests is highly leached and has a low base content. They require a mean annual temperature of 23-27 °C and 2000-3500 mm rainfall.
  • Tropical deciduous forests: They occur in the northern and southern parts of our country in plains and low hilly areas. Sal, teak, and tendu are the common trees of these forests. These forests show a short structure of 10-20 m. During rainy season, the forest is lush green with dense foliage, whereas in summer, the forest is largely leafless. The soil of these forests is rich in nutrients due to less leaching. They require a mean annual temperature of 22-32°C and mean annual rainfall of 900-1600 mm.
  • Desert: In these biomes, vegetation is very sparse due to extreme temperatures and very little rainfall (below 10 cm). Hot deserts are characterized by high rate of evapotranspiration and albedo. In cold deserts, the conditions are physiologically xeric and they exhibit permafrost, while in hot deserts, the conditions are physically xeric. Important trees of Indian desert are Prosopis cineraria, Acacia sp., Salvadora sp., and Tamarix sp. The common succulents are species of Euphorbia and many members of family Cactaceae.

NEET Biology Organisms And Populations Biome distribution with respect to annual temperature and precipitation

  • Coastal biome: Coastal areas are zones of transition between oceanic and terrestrial habitats and, so, are very sensitive. These are detritus-based biomes, where plants have to adapt to salinity and water-logged conditions. Mangroves are the major types along salt marshes or swamps. Mangroves are characterized by the presence of pneumatophores and viviparous seed germination. Common examples are Rhizophora, Sonneratia, Avicennia, and Laguncularia. Besides, Phoenix, Pandanus, and Casuarina are also found commonly in coastal areas.

 

NEET Biology Notes For Organisms And Populations Response To Abiotic Factors

A change in one environmental factor leads to change in others also. In other words, all factors are integrated. An organism would have evolved various mechanisms to maintain its internal environment at homeostasis to perform its physiological and biochemical functions. This constancy is necessary for its overall fitness or maximum performance. This may be maintained naturally or artificially.

” basic functional unit to study the ecology is termed as”

NEET Biology Organisms And Populations Diagrammatic representation of organismic response

  • Regulate: All birds and mammals and a few lower vertebrates and invertebrates maintain homeostasis by physiological or behavioral means such as thermoregulation and osmoregulation. But plants do not have such mechanisms to regulate homeostasis. The evolutionary success of mammals is believed largely due to this ability.
  • Conform: When organisms cannot maintain thermal and osmotic balance with their environment, they adopt this mechanism, e.g., approximately 99% plants and animals. Thermoregulation is energetically expensive, especially for small animals having large surface area relative to their volume. Due to this, very small animals are rare in polar regions. Some species have the ability to regulate up to a limited range beyond which they become conform (partial regulators).
    For localized or short outburst of stressful conditions, organisms show migration or suspended growth.
  • Migrate: It is the temporary movement of organisms from a stressful area to a more favorable one in terms of food, shelter, spawning, or climate. For example, Siberian cranes migrate from Siberia to Keoladeo National Park, also known as Bharatpur Bird Sanctuary, in Rajasthan. Locums migrate for food and salmon fish migrates for spawning. Similarly, ungulate’s migration in Africa takes place for food.
  • Suspend: It is a stage in the life cycle of organisms where they change their developmental/physiological structural/biochemical behavior to pass through unfavorable conditions. Examples are thick-walled spores in bacteria, fungi, and lower plants; dormancy in seeds and other vegetative parts in higher plants; and hibernation (winter sleep) among organisms which are un- able to migrate, e.g., bears.
  • Aestivation: It is the metabolic inactivity of organisms during hot desiccating summer, e.g., snails and fish.
  • Diapause: It is the stage of temporary suspension of development under unfavorable conditions, e.g., zoo- plankton in lakes and ponds.

Adaptation

Adaptation is an attribute of an organism that enables it to survive and reproduce in its habitat. Adaptations may be morphological, physiological, or behavioral. These are either fixed genetically or remain epigenetic.

Some examples of adaptation are as follows:

  • The kangaroo rat of North American desert fulfills its water demands by internal oxidation of fats. It also has the ability to concentrate its urine.
  • Mammals from a colder climate generally have shorter ears and limbs to minimize heat loss. Here, Allen’s rule is at work.
  • Seals have a thick layer of fat (blubber) below the skin to reduce loss of body heat.
  • Altitude sickness can be expressed at high altitudes where body does not get enough oxygen due to low atmospheric pressure, causing nausea, fatigue, and heart palpitations. Under these conditions, the body increases RBC production, decreases the binding capacity of fibrils, and increases breathing rate. These physiological adaptations allow organisms to respond quickly to stressful conditions.
  • Archaebacteria can flourish at a temperature exceeding 100°C, while humans can perform metabolism in a narrow range (37°C).
  • Antarctic fishes can survive below 0°C, and a variety of invertebrates and fishes are adapted biochemically to survive great depths with crushing pressure.
  • Desert lizards lack the physiological ability to cope with extreme temperatures, but manage the body temperature by behavioral means.

Water-Based Adaptations

On the basis of dependence of plants on water and their relationship with water, Warming (1909) recognized three kinds of plant communities: hydrophytes, xerophytes, and mesophytes.

Hydrophytes: They live in abundance of water with at least their lower parts (roots) and leaves submerged.

Roots of hydrophytes are poorly developed/completely absent in Wolffia, Ceratophyllum, etc.

  • Stems in hydrophytes are of three kinds:Reduced in free floating plants (e.g., Pistia).
  • Narrow and slender in submerged, suspended plants (e.g., Hydrilla and Ceratophyllum).
  • Well-developed in amphibious plants and rhizome growing through the mud (e.g., Nymphaea and Typha).

Leaves in hydrophytes are of the following kinds:

  • Usually long ribbon-like (e.g., Potamogeton) or finely divided (e.g., Ranunculus).
  • In some hydrophytes, leaves of different forms are produced by the same plant-aerial leaves are not dissected but submerged ones are dissected (e.g., Ra-nunculus aquatilis and Limnophila. This is known as heterophylly.
  • Petioles become long, swollen, and spongy (e.g., Nymphaea, Nelumbo, and Saggitaria).

Hydrophytes show the following anatomical adaptations:

  • There is no cuticle over the epidermis.
  • Stomata either are absent or are dysfunctional.
  • Aerenchyma is well developed.
  • Epidermal cells contain chloroplasts.
  • Mechanical tissues such as sclerenchyma and collenchyma are poorly developed.
  • Vascular tissues are poorly developed,
  • Secondary growth is absent.
  • Vegetative propagation is common by runners (e.g., Marsilea), offsets (e.g., Pistia and Eichhornia), rhizomes (e.g., Typha), and turions (fleshy buds, e.g., Potamogeton).
  • Xerophytes: These plants show anatomical and physiological adaptations.Anatomical adaptations: Thick-walled epidermal cells, multiple epidermis (e.g., Nerium), thick cuticle, hypodermis sclerenchymatous, stomata sunken and covered by hair (e.g., Nerium, Casuarina, and Ephedra), water storing parenchyma well developed, conducting and mechanical tissues well developed, palisade multilayered, and cells of succulents contain abundant mucilage.
  • Physiological adaptations: Reduction of transpiration, high osmotic potential, and resistance to desiccation of mucilage to hold water.

On the basis of the nature of soil and causes of unavailability of water, xerophytes are divided into the following categories:

  • Physical xerophytes: These plants grow in soils. which are physically dry (due to shortage of water), e.g., Opuntia, Casuarina, Ruscus, Muehlenbeckia (Coccoloba), etc.
  • Physiological xerophytes: These plants grow in soils having sufficient water which is not available due to high salt concentration (salinity) or very low temperature.

On the basis of life cycle and water storage, xerophytes are divided into the following categories:

  • Ephemerals: These plants are short-living, i.e., have a brief lifespan (6-8 weeks). These evade dry season by disappearing, leaving behind their seeds. Hence, these plants are not true xerophytes, rather drought evaders and drought escapers, e.g., Cassia tora and Tribulus.
  • Succulents (fleshy xerophytes): These plants absorb a large quantity of water during rainy season and store it in different body parts. These suffer only externally. Hence, these are drought avoiding or drought-resistant xerophytes. These are further divided into the following:
    • Stem succulents: e.g., Opuntia, Euphorbia antiquorum, E. splendens, E. tirucolli, and Cereus.
    • Leaf succulents: e.g., Aloe, Agave, Begonia, and Bryopnyiium.
    • Root succulents: e.g., Asparagus and Hebe parviflora.
  • Nonsucculents: These plants are drought endurers and true xerophytes, and can withstand long drought periods (perennial nonsucculents), e.g., Casuartna, Zizyphus, Nenrium, Calotropis, Acacia, and Capparis.

Halophytes: Halophytes are special types of xerophytic plants which grow in saline soils with high concentrations of salts such as NaCl, MgCl2, and MgSO (hence, physiologically dry soil). Halophytic communities growing on swamps are called halophytes.

” organisms and population class 12 ppt “

NEET Biology Notes For Organisms And Populations For Population

Population is of two types. One is called deme, which stands for local population living in a specific area. The other is meta population, which consists of the whole set of local populations connected by dispersing individuals.

For the purpose of ecological studies, a group of individuals resulting from asexual reproduction is also considered population.

Population Attributes/Group Attributes

Some characteristics are unique to the group and are not the characteristics of the individuals forming it; for example, an organism is born and dies, and has a specific age, but it does not have birth rate, death rate, and age ratio.

Population characteristics can be best expressed by statistical methods. Some important characteristics are discussed next.

Population Density

Density is the number of individuals per unit area; e.g., millions of Spirogyra filaments in a pond or 200 Parthenium plants in an area. This can also be expressed as “the population biomass per unit area or volume” when we have to count a large number of organisms or find out the role of a single huge banyan tree in an area.

Relative density is a good measure of finding out the total density of fishes in a lake by counting the number of fishes caught per trap. Another example of measuring the size of a population is tiger census in India. This census is based on pug marks and fecal pellets which are used to indirectly estimate the population size of tigers.

Age Ratio Pyramids

An age pyramid is a graphic representation of the proportion of various age groups in a population. There are three types of age pyramids: triangular, bell-shaped, and urn-shaped.

Triangular pyramid: It is the graphic representation of a young or growing population and has a very high proportion of pre-reproductive individuals.

Bell-shaped pyramid: The pyramid is bell-like with pre-reproductive individuals only marginally more than the reproductive individuals. The population is mature or stable.

Urn-shaped pyramid: It has a small number of pre-reproductive individuals, a larger number of reproductive individuals, and a small number of post- reproductive individuals. Such a population shows negative growth.

NEET Biology Organisms And Populations Representation of age pyramids for human population

Population Growth

Some attributes of population are used to estimate its growth as population size may fluctuate in a given habitat in a given period due to changes in the four basic processes discussed as under.

  • Natality: It is the birth rate (an inherent ability of a population to increase) and refers to the number of births in the population during a given period that are added to its initial density.
    The per individual change in a population due to natal- ity can be estimated using AN/Nat,
    where AN, is the number of new individuals produced, Nis the initial population, and At is the change in time.
  • Mortality: It is the death rate (the number of individual dying in a population in a given period).
  • Immigration: It is one-way permanent inward movement of individuals of the same species into a habitat with existing population. This may help to speed up the growth or prevent extinction of a smaller population. In plants, it is a settlement of disseminules.
  • Emigration: It is one-way permanent outward movement of a number of individuals from a population to other habitat area, hence, reducing the size of that local population. Plants are fixed and, so, do not show emigration.

By these population characteristics, the density of a population (M) at time t can be expressed after a period of time t+1 as

N(+1) = N; + [(B + 1) − (D + E)]

where B is the number of births, I is the number of immigrants, D is the number of deaths, and E is the number of emigrants.

NEET Biology Organisms And Populations Schematic of population growth

So, it can be concluded that births and deaths are the most important factors influencing population density.

Growth Models

Biotic potential and environmental resistance: Biotic potential (r) is the maximum or potential natality. The sum of environmen- tal factors that limits the population size is called environmental resistance. Environmental resistance rises with the rise in popula- tion size. The influence of environmental resistance over biotic potential is denoted by (K – N)/N.

Carrying capacity (K): The maximum number of individuals of a population which can be supported with optimum resources for their survival is called the carrying capacity of the environment. The growth of a population depends on its biotic potential, death rate, and birth rate. Depending upon the amplitude of these three, a population may show exponential growth and logistic growth.

  • Exponential growth: Darwin believed a population grows geometrically when the resources are unlimited, as each species realizes its inherent potential to grow. This intrinsic rate of natural increase is called r. The value of r is an important parameter to assess the impact of environmental factors on population growth.
    • Any increase or decrease in a population N during time t (dNidt) will be dN/dt = (b-d) x N, where b is the per capita birth rate and d is the per capita death rate. If (bd) = r, then, dN/dt = rN.
    • The magnitude of r was 0.0205 for human population in India, while it reached 0.0176 in 2001. For Norway rat, it is 0.015 and for flour beetles, it is 0.12.
    • Equation dN/dt = rN describes geometric growth resulting in a J-shaped curve. Such population stops abruptly due to environmental resistance, which suddenly becomes effective, or depletion of a resource. Decline in a J-shaped population is density-triggered, e.g, algal blooms insect population.

” class 12 organism and population notes”

NEET Biology Organisms And Populations Population growth curve

  • Logistic growth: This growth form is characterized by a function of carrying capacity (K) for a given population, giving it a more realistic form. Such forms are represented under limited resource conditions, where a population finally reaches an asymptote. This growth form can be described as the Verhulst-Pearl logistic growth and is expressed as
    dN/dt = rN(K-N/K)

    • Life history variation: Any variation in life history is evolved in relation to the selection pressure imposed by environmental factors in order to achieve the most efficient reproductive strategy such as the following:
      • A small number of large-sized individuals are produced (e.g., mammals and birds).
      • A larger number of small-sized individuals are produced (e.g., oysters and fishes).
      • Some organisms breed once in their life time (e.g., Bambusa and Pacific salmon).
      • Some organisms breed many times during their life-time (e.g., mammals and many birds).

Population Interactions

Many populations of different species may require a similar set of environmental gradient where they live and interact with each other and environment in order to survive and perform their activities. These interactions may be assigned “+,” “_” or “0,” where “+” is beneficial, “-” is detrimental, and “0” is neutral.

  • Negative interactions: These are interactions between two species where one species affects others’ growth and survival.
  • Competition: It is a process in which the fitness (r) of one species is significantly lower in the presence of other species.
    • Competition affects plants and herbivores more than carnivores.
    • This may occur between totally unrelated species when they compete for the same resource, e.g., competition for zooplankton between visiting flamingoes and resident fishes in South American lakes.
    • Resources need not be limiting for competition to occur; the feeding efficiency of one species might be reduced due to the inhibitory or interfering presence of other species.

According to Gause’s competitive exclusion principle, two closely related species competing for the same resources cannot coexist indefinitely and the competitively inferior species will be eventually eliminated. Gause performed his experiments on two species of Paramecium: P. aurelia and P. caudatum.

Coexistence: Species facing competition might evolve a mechanism to live in the same niche by changing the feeding time or foraging patterns. This is called resource partitioning. For example, five closely related species of warblers avoid competition by changing their foraging pattern..

Habitat diversification can also reduce competition, e.g., Tribolium and Oryzaephilus. Tribolium Trifolium model best explains both exclusion and coexistence. There are some circumstantial evidences which support the exclusion of species due to competition. For example,

  • Introduction of goats resulted in the exclusion of Abingdon tortoise from Galapagos Islands.
  • The same interaction occurs between Balanus and Chthamalus on the rocky coasts of Scotland.

Competitive release: There occurs a dramatic increase in the population of a less distributed species in a geographical area when its superior competitor is removed experimentally from that area.

Predation: It is an interaction between species involving killing and consumption of prey.

Predation plays the following roles:

  • Transfer of energy (in ecological sense, herbivores are not very different from predators).
  • Keeping prey population under control.
  • The rabbit population in Australia increased tremendously because the land does not have its natural predators. The introduction of prickly pear cactus (Opuntia) in Australia was controlled only after the introduction of its natural predator moth (Cactoblastis cactorum). Similarly, red foxes in New Zealand have become top carnivores due to the absence of a natural carnivore.
  • Predators help maintain species diversity in a community as they can reduce the intensity of competition among prey species; e.g., experimental removal of Pisaster (star fish) resulted in the extinction of more than ten species of invertebrates.
  • According to the Slobodkin’s principle of prudent predator, a predator does not exterminate its prey by overexploitation.

For their defense, prey species have evolved various adaptations, which are listed as follows:

NEET Biology Organisms And Populations Predation

  • Monarch butterfly is well known for its general unpalatability to its predator birds. This insect is able to sequester highly toxic glycosides present in milkweeds on which its caterpillar stages feed. There larvae develop on milkweed providing the protection to plant against herbivory.
  • Cardiac glycosides are produced by Calotropis. Nicotine, caffeine, quinine, and strychnine are other means of chemical defense in plants.
  • The association of bullhorn Acacia cornigera with Pseudomyrmex ferruginea (acacia ant) is a defense against herbivory. This is also an example of coevolution.

Parasitism: This also depresses the growth rate of a population or may reduce the total size of the population. Parasites are generally smaller. Majority of them are host-specific. A high reproductive potential, loss of digestive system and unnecessary sense organs, and the presence of specific sucking or adhesive organs are some of their characteristics, but they have poor means of dispersal.

Various types of parasites are given as follows:

  • Ectoparasites: Examples are lice on humans, ticks on dogs, copepods on marine fishes, and Cascuta on hedge plants.
  • Endoparasites: These are extremely specialized parasites, with a complex life cycle but simplified morphologically and anatomically. Examples are liver fluke, plasmodium, etc.
  • Brood parasitism: An example of this type of parasitism is cuckoo which lays its eggs in a crow’s nest.
  • Hyperparasites: Examples are bacteriophages, which are parasite over parasitic bacteria. Similarly, Pasteurella pestis is a parasite of rat flea, which is a rat parasite.
  • Amensalism (-, 0): It is both a detrimental and a neutral relationship, where chemical secretion by one organism inhibits the growth of the other. Examples are allelopathic plants such as Prosopis juliflora and black walnut.

Positive interactions: It is an association between two species where one or both populations realize positive effects. This is necessary to achieve homeostasis.

Commensalism (+, 0): It is the simplest form of interaction, in which one species is benefitted while the other is neither harmed nor benefitted. Examples are orchid epiphytes on mango trees, cattle egret and grazing cattle, barnacles growing on the back of a whale, clown fish and sea anemone, and pilot and sucker fish with shark.

Mutualism (+, +): It is an obligatory relation where both species are benefitted. It is essential for their survival on the earth. Examples are mutualistic N2-fixing relation, lichens, mycorrhiza, termite-intestinal flagellate relation, and plant-pollinator relation. Sometimes, it is a one-to-one coevolution- ary relation such as fig and wasp relation, Ophrys and Colpa relation, and Yucca and Pronuba relation.

Some insects such as queens of Bombus affinis cheat plants to steal nectar from the spurs of Aquilegia.

Proto-cooperation (+, +): It is a nonobligatory relation where organisms of both species are benefitted. Examples are oxpecker and rhinoceros, and plover bird and crocodile.

NEET Biology Notes For Organisms And Populations Question And Answers

In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R).

  1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark (1).
  2. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
  3. If Assertion is true but Reason is false, then mark (3).
  4. If both Assertion and Reason are false, then mark (4).

Question 1. Assertion: Holistic approach explains the environmental interactions.

Reason: All environmental factors are integrated with no limits of time and space.

Answer. 3. If Assertion is true but Reason is false, then mark (3)

Question 2. Assertion: Some organisms can maintain internal homeostasis by means of physiological processes and are called “regulates.”

Reason: Regulates can maintain internal homeostasis only up to a limit under stressful conditions.

Answer. 3. If Assertion is true but Reason is false, then mark (3)

Question 3. Assertion: Population ecology is a link of ecology to population genetics and evolution.

Reason: Natural selection operates at population level to evolve the desired traits.

Answer. 1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark (1).

Question 4. Assertion: Under unlimited resource conditions, a population can show an exponential growth curve.

Reason: The maximum possible number of individuals can always be supported when enough resources are available.

Answer. 2. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark

Question 5. Assertion: Insects contribute the maximum to the total diversity of animals.

Reason: Angiosperms and insects are coevolved to perform as plant-pollinator.

Answer. 1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark (1).

NEET Biology Multiple Choice Questions – Bio Technology And Its Applications

by

NEET Biology Bio-Technology And Its Applications Multiple Choice Questions

Question 1. Which one of the following can be used as a permanent cure for ADA deficiency?

  1. Bone marrow transplantation on detection of disorder in adults.
  2. Enzyme replacement therapy at any point in life.
  3. Both (1) and (2).
  4. Gene therapy at early embryonic stages.

Answer. 4. Gene therapy at early embryonic stages.

Question 2. Which one of the following is a transgenic product useful for the treatment of hemophilia?

  1. Factor VIII
  2. Antithrombin II
  3. α-1-antitrypsin
  4. Lysostaphin

Answer. 1. Factor VIII

Question 3. Who is responsible for obtaining interferons through re- combinant DNA technique?

  1. A.R. Bounting
  2. Eli Lily
  3. Charles Weissmann
  4. A. Tiselius

Answer. 3. Charles Weissmann

Question 4. Select the incorrect statement:

  1. RNAi silencing takes place in all eukaryotic organ- isms as a method of cellular defense.
  2. RNAi requires silencing of mRNA by binding of complementary ssDNA molecule.
  3. Complementary nucleic acid could be from mobile genetic elements (transposons).
  4. Ti plasmid with nematode-specific genes has been used in RNAi.

Answer. 2. RNAi requires silencing of mRNA by binding of complementary ssDNA molecule.

Question 5. Which gene controls the transcription of chain A and chain B required for humulin synthesis in E. coli?

  1. B-Lactamase
  2. B-Galactosidase
  3. Polygalacturonase
  4. Chitinase

Answer. 2. B-Galactosidase

Question 6. Transgenic Brassica napus has been used for the synthesis of

  1. Hirudin
  2. Heparin
  3. Polygalacturonase
  4. Cry protein

Answer. 1. Hirudin

Question 7. Which genes encode the protein to control bollworm infection in cotton plants?

  1. Cry II Ab
  2. Cry I Ac
  3. Both (1) and (2)
  4. Amp

Answer. 3. Both (1) and (2)

Question 8. Which is incorrect with respect to GM food?

  1. It contains the protein produced by the transgene in question.
  2. GM food contains antibiotic resistance gene itself.
  3. The enzyme produced by antibiotic resistance gene will not cause allergies.
  4. The bacteria in gut of humans could take by antibiotic resistance gene.

Answer. 3. The enzyme produced by antibiotic resistance gene will not cause allergies.

Question 9. Golden rice-a transgenic variety of rice is principally richer than normal rice in

  1. Cry I Ab
  2. Hirudin
  3. TPA
  4. B-carotene

Answer. 4. B-carotene

Question 10. Southern blotting cannot be performed without

  1. Restriction endonucleases
  2. Agarose
  3. Monoclonal antibodies
  4. Both (1) and (2)

Answer. 4. Both (1) and (2)

Question 11. Plants, bacteria, fungi, and animals whose genes have been altered by manipulation are called genetically modified organisms (GMO). Which of the following statement is not applicable to GM plants?

  1. Reduced reliance on chemical pesticides.
  2. Prevent early exhaustion of fertility of soil.
  3. Crops less tolerant to abiotic stress (cold, drought, salt, and heat).
  4. Enhanced nutritional value of food.

Answer. 3. Crops less tolerant to abiotic stress (cold, drought, salt, and heat).

Question 12. In case of Bacillus thuringiensis, Bacillus itself is not killed by toxic protein crystals produced by it because

  1. Bt toxin protein is not produced in Bacillus
  2. Bt toxin protein is produced in very less amount in Bacillus
  3. Bt toxin exists as inactive toxin
  4. Bt toxin cannot cause any damage to Bacillus

Answer. 3. Bt toxin exists as inactive toxin

Question 13. Bt toxin kills the insect by

  1. Blocking nerve conduction
  2. Damaging the surface of trachea
  3. Creating pores in the tracheal system
  4. Creating pores in the mid gut

Answer. 4. Creating pores in the mid gut

Question 14. Which of the following cry gene codes for the protein which can control the corn borer effectively?

  1. cry I Ac
  2. cry II Ab
  3. cry I Ab
  4. cry II Ac

Answer. 3. cry I Ab

Question 15. RNA interference (RNAi) technique has been devised to protect plants from nematode. In this technique, the mRNA of nematode is silenced by _______ produced by the host plant.

  1. dsDNA
  2. ssDNA
  3. dsRNA
  4. Target proteins

Answer. 3. dsRNA

Question 16. Which of the following peptide chain is removed during the maturation of pro-insulin into insulin?

  1. A peptide
  2. B peptide
  3. C peptide
  4. A and C peptides

Answer. 3. C peptide

” short notes on biotechnology”

Question 17. Eli Lilly, an American company, prepared two DNA se- quences corresponding to A and B chains of human insulin and introduced them in the plasmids of E. coli to produce insulin chains. Chains A and B were produced separately, extracted, and combined by creating

  1. Peptide bonds
  2. Ionic bonds
  3. H-bonds
  4. Disulfide bonds

Answer. 4. Disulfide bonds

Question 18. The first clinical gene therapy was given in 1990 to a 4-year old girl with which of the following enzyme deficiency?

  1. Adenosine deaminase
  2. Tyrosine oxidase
  3. Monamine oxidase
  4. Glutamate dehydrogenase

Answer. 1. Adenosine deaminase

Question 19. Which of the following could be a permanent cure for the treatment of severe combined immunodeficiency (SCID)?

  1. Bone marrow transplantation
  2. Enzyme replacement therapy
  3. Both (1) and (2)
  4. Gene therapy

Answer. 4. Gene therapy

Question 20. Which of the following technique is being used to detect mutations in genes in suspected cancer patients?

  1. PCR
  2. ELISA
  3. Blood analysis
  4. PAGE

Answer. 1. PCR

Question 21. Animals that have had their DNA manipulated to possess and express an extra gene are known as

  1. Foreign animals
  2. Superior animals
  3. Transgenic animals
  4. Intergenic animals

Answer. 3. Transgenic animals

Question 22. About 95% of all existing transgenic animals are

  1. Rabbits
  2. Pigs
  3. Cows
  4. Mice

Answer. 4. Mice

Question 23. Today, transgenic models exist for many human diseases which includes

A. Cancer

B. Cystic fibrosis

C. Rheumatoid arthritis

D. Alzheimer’s disease

  1. (A) and (C) only
  2. (B) and (C) only
  3. (A), (B), and (C) only
  4. All of these

Answer. 4. All of these

Question 24. Which of the following is not a true statement with respect to Bt cotton?

  1. Bt toxin is produced by a bacterium Bacillus thuringiensis.
  2. It is an example of biopesticide.
  3. Bt toxin gene has been cloned in plants to provide resistance to insects.
  4. Bt cotton could decrease the amount of pesticide used.

Answer. 3. Bt toxin gene has been cloned in plants to provide resistance to insects.

Question 25. How many recombinant therapeutics have been approved for human use all over the world?

  1. 12
  2. 30
  3. 20
  4. 18

Answer. 2. 30

Question 26. Which of the following techniques serve the purpose of early diagnosis?

A. Recombinant DNA technology

B. PCR

C. ELISA

  1. (A) only
  2. (A) and (C) only
  3. (A) and (B) only
  4. All of these

Answer. 4. All of these

Question 27. Which of the following technique is based upon the principle of antigen-antibody interaction?

  1. PCR
  2. ELISA
  3. Recombinant DNA technology
  4. RNA interference

Answer. 2. ELISA

Question 28. Which of the following transgenic protein product has been used to treat emphysema?

  1. α-l-Antitrypsin
  2. α-Lactalbumin
  3. Cry protein
  4. C-peptide

Answer. 1. α-l-Antitrypsin

Question 29. How many varieties of rice have been estimated to be present in India?

  1. 2000
  2. 20,000
  3. 2,00,000
  4. 20,00,000

Answer. 3. 2,00,000

Question 30. The use of bioresources by multinational companies and other organizations without proper authorization from the countries and people concerned without compensatory payment is called

  1. Bioethics
  2. Biopiracy
  3. Bioterror
  4. Bioweapon

Answer. 2. Biopiracy

Question 31. Amongst the following, which characteristic is not applicable to Bt cotton?

  1. Bt is the abbreviated term for botulinum toxin.
  2. Such cotton is resistant to armyworms and beetles.
  3. The toxin is activated in the body of the insect.
  4. The toxin is coded by a gene called “cry.”

Answer. 1. Bt is the abbreviated term for botulinum toxin.

Question 32. Which biotechnology company is credited with the synthesis of genetically engineered human insulin for the first time?

  1. Celera genomics
  2. Cipla
  3. Eli Lily
  4. Ranbaxy

Answer. 3. Eli Lily

Question 33. Functional ADA cDNA can be introduced into the cells of the patient receiving gene therapy by using a vector constituted by

  1. E. coli
  2. Reovirus
  3. Retrovirus
  4. Agrobacterium

Answer. 3. Retrovirus

Question 34. Which variety of rice was patented by a US company even though the highest number of varieties of this rice is found in India?

  1. Shamati Sonara
  2. Co-667
  3. Basmati
  4. Lerma Roja

Answer. 3. Basmati

Question 35. Which step has the Government of India taken to cater to the requirement of patent terms and other emergency provisions in this regard?

  1. Biopiracy Act
  2. Indian Patents Bill
  3. RTI Act
  4. Negotiable Instruments Act

Answer. 2. Indian Patents Bill

Question 36. What is another term used for GMO (genetically modified organisms)?

  1. Cybrid organisms
  2. Genomorphic organisms
  3. Transgenic organisms
  4. Conjoint twins

Answer. 3. Transgenic organisms

Question 37. Transgenic models can be used to investigate several human diseases such as

  1. Alzheimer’s disease
  2. Cystic fibrosis
  3. Carcinoma
  4. All of these

Answer. 4. All of these

Question 38. Which GMO is now being developed in order to be used in testing the safety of polio vaccines before they are used in humans?

  1. Transgenic sheep
  2. Transgenic cow
  3. Transgenic mice
  4. Transgenic viruses

Answer. 3. Transgenic mice

Question 39. Which method of cellular defense is common in all eukaryotic organisms?

  1. RNA interference
  2. Reverse transcription
  3. VNTR
  4. Phagocytosis

Answer. 1. RNA interference

importance of biotechnology

Question 40. “Silencing” of mRNA molecule in order to control the production of a harmful protein has been used in the protection of plants from

  1. Nematodes
  2. Beetles
  3. Mosquitoes
  4. Flies

Answer. 1. Nematodes

Question 41. Mark the odd one with respect to the advantages of genetically modified plants:

  1. Production of food with better nutritional value.
  2. Decrease in post harvest losses.
  3. Decreased dependence on fertilizers.
  4. Decreased usage of minerals.

Answer. 4. Decreased usage of minerals.

Question 42. In which disease has the advancement of genetic engineering still not been used as clinical cure?

  1. Emphysema
  2. Cystic fibrosis
  3. Phenylketonuria
  4. Anencephaly

Answer. 4. Anencephaly

Question 43. Which substance is tested in case of toxicity/safety testing using transgenic animals?

  1. Chemicals
  2. Pathogen
  3. The amount of DNA in the cell
  4. The amount of tolerable radiation levels of an organism

Answer. 1. Chemicals

Question 44. Which step proved to be the main challenging obstacle in the production of human insulin by genetic engineering?

  1. Removal of C-peptide from active insulin.
  2. Getting insulin assembled into a mature form.
  3. Addition of C-peptide to pro-insulin.
  4. Splitting A and B polypeptide chains.

Answer. 2. Getting insulin assembled into a mature form.

Question 45. What is the disadvantage of using processed insulin (from pig pancreas) in diabetic patients?

  1. It leads to hypercalcaemia.
  2. It may cause allergic reactions.
  3. It is expensive.
  4. It can lead to mutations in human recipients.

Answer. 2. It may cause allergic reactions.

Question 46. Why are repeated transfusions of genetically engineered cells required in SCID patients?

  1. The transfused cells have limited lifespan.
  2. The introduced gene is mutated.
  3. The enzyme required is degraded after 20 days of transfusion.
  4. Both (2) and (3).

Answer. 1. The transfused cells have limited lifespan.

Question 47. Which Indian plants have either been patented or attempts have been made to patent them by the Western nations for their commercial use?

  1. Basmati rice
  2. Turmeric
  3. Neem
  4. All of these have been targeted

Answer. 4. All of these have been targeted

Question 48. Why is insulin usually not administered orally to a diabetic patient?

  1. Insulin is bitter in taste.
  2. Insulin is a peptide.
  3. Insulin will lead to a sudden decrease in blood sugar if given orally.
  4. Insulin leads to peptic ulcer orally.

Answer. 2. Insulin is a peptide.

Question 49. Which technique would you expect to be completely curative in SCID?

  1. Gene therapy in adult stage.
  2. Gene therapy in embryonic stage.
  3. Bone marrow transplantation.
  4. Enzyme replacement therapy.

Answer. 2. Gene therapy in embryonic stage.

Question 50. A doctor while operating on an HIV+ patient accidentally cut himself with a scalpel. He comes to you, suspecting himself to have contracted the virus. Which test will you advise him to rule out/confirm his suspicion?

  1. PCR
  2. Routine urine examination
  3. TLC
  4. DLC

Answer. 1. PCR

Question 51. Match the following genes in column 1 with the insects that can be protected from with their coded proteins in column 2.

Column 1                    Column 2

a. cry I Ac                   (1) Cotton bollworm

b.cry I Ab                  (2) Beetles

c. Bt toxin gene        (3) Corn borer

  1. a (1), b (3), c (2)
  2. a (2), b (1), c (3)
  3. a (1), b (2), c (3)
  4. a (2), b (3), c (1)

Answer. 1. a (1), b (3), c (2)

Question 52. Which protein would you like to be produced by genetic engineering as cure for diseases such as emphysema?

  1. α-1-Antitrypsin
  2. Trypsin
  3. Chymotrypsin
  4. All of the above are required

Answer. 1. α-1-Antitrypsin

Question 53. “Rosie,” a transgenic cow, is known to produce a type of milk which has all the following characteristics, except

  1. Protein content of 2.4 g/L
  2. Has human a-lactalbumin
  3. More balanced diet than normal cow milk for babies
  4. Was produced for the first time in 2001

Answer. 4. Was produced for the first time in 2001

Question 54. According to the latest estimates, how many documented varieties of basmati rice are grown in India?

  1. 30
  2. 27
  3. 118
  4. 125

Answer. 2. 27

Question 55. Which ingredient was present in high concentrations in genetically modified (GM) rice as compared to the usual rice?

  1. Protein
  2. Carbohydrates
  3. Na+ ions
  4. Vitamin A

Answer. 4. Vitamin A

“application of biotechnology “

Question 56. Which of the following cannot be achieved using PCR?

  1. Detect HIV in AIDS suspect.
  2. Detect mutations in cancer patients.
  3. Detect antigen-antibody interactions
  4. Detect specific microorganisms from soil.

Answer. 3. Detect antigen-antibody interactions

Question 57. In electrophoresis, the separation of DNA fragments is based on

  1. Charge
  2. Mass only
  3. Size
  4. Both (1) and (3)

Answer. 4. Both (1) and (3)

Question 58. Pick the odd one out:

  1. DNA microinjection
  2. RNA interference
  3. Retro virus mediated gene transfer
  4. Embryonic stem cell mediated gene transfer

Answer. 2. RNA interference

Question 59. In xenotransplantation, a protein that causes graft rejection usually comes from transgenic

  1. Cow
  2. Mice
  3. Pig
  4. Sheep

Answer. 3. Pig

Question 60. Transgenics has provided many pharmaceuticals in their milk for the treatment of diseases. Which one of the following has not been a successful story?

  1. Phenylketonuria
  2. SCID
  3. Emphysema (hereditary)
  4. CFTR

Answer. 2. SCID

Question 61. Which is not true with respect to transgenic animals and their contribution to human welfare?

  1. Transgenic mice are being tested to ensure safety of polio vaccine.
  2. Rosie’s milk contained human gene insulin.
  3. Transgenic cows produce milk with less lactose.
  4. Transgenic sheep grow more wool.

Answer. 2. Rosie’s milk contained human gene insulin.

Question 62. An antibacterial compound that prevents mastitis in cows is

  1. α-1-Antitrypsin
  2. Lysostaphin
  3. Lysozyme
  4. Alginate lyase

Answer. 2. Lysostaphin

Question 63. Choose the incorrect statement with respect to bioweapons:

  1. They are low-cost weapons.
  2. They cause more casualties than conventional weapons.
  3. They are extremely difficult to detect.
  4. Bacterium E. coli created letter scare in 2001.

Answer. 4. Bacterium E. coli created letter scare in 2001.

“biotechnology notes “

Question 64. A set of standards by which a community regulates its behavior and activities in relation to the biological world is termed as

  1. Biopatent
  2. Biopiracy
  3. Patent
  4. Bioethic

Answer. 4. Bioethic

Question 65. Nexia Biotechnologies spliced spider genes into the cells of lactating

  1. Cow
  2. Sheep
  3. Goat
  4. None of these

Answer. 3. Goat

Question 66. Nif gene for nitrogen fixation in cereal crops such as wheat and jowar is introduced by cloning

  1. Rhizobium meliloti
  2. Bacillus thuringiensis
  3. Rhizopus
  4. Rhizophora

Answer. 1. Rhizobium meliloti

Question 67. VNTRS represent

  1. New terminal regions in DNA
  2. Functional genes in DNA
  3. Split genes in sample DNA
  4. Specific non-coding sequences with unique tandem repeats

Answer. 4. Specific non-coding sequences with unique tandem repeats

Question 68. Sheep Dolly was genetically similar to

  1. The mother from which nucleated fertilized egg was taken
  2. The mother from which the nucleus of udder cell was taken
  3. The surrogate mother
  4. Both surrogate mother and nuclear donor mother

Answer. 2. The mother from which the nucleus of udder cell was taken

Question 69. How does a bacterial cell protect its own DNA from restriction enzymes?

  1. By adding methyl groups to adenines and cystosines.
  2. By reinforcing bacterial DNA structure with covalent phosphodiester bonds.
  3. By adding histones to protect the double-stranded DNA
  4. By forming “sticky ends” of bacterial DNA to prevent the enzyme from attaching.

Answer. 1. By adding methyl groups to adenines and cystosines.

Question 70. All cells contain the same genetic information. Why cannot cells other than stem cells differentiate into various tissues?

  1. As cells develop, their genetic makeup changes.
  2. Stem cells are the only cells that can be implanted.
  3. Stem cells are the only cells that do not have an X or Y chromosome and can, therefore, go into either a male or a female.
  4. As cells develop, some genes are turned off permanently.

Answer. 4. As cells develop, some genes are turned off permanently.

“biotechnology applications “

Question 71. Polymerase chain reaction technology (PCR-technique) is used for

  1. DNA identification
  2. DNA repair
  3. DNA amplification
  4. Cleave DNA

Answer. 3. DNA amplification

Question 72. Which scientists obtained interferon through recombinant DNA technology?

  1. Kohler and Milstein
  2. Charles Weisman
  3. Nathans and Smith
  4. An American firm

Answer. 2. Charles Weisman

Question 73. When the genotype of an organism is improved by the addition of a foreign gene, the process is called

  1. Tissue culture
  2. Genetic diversity
  3. Genetic engineering
  4. Plastic surgery

Answer. 3. Genetic engineering

Question 74. A genetically manipulated organism containing in its genome one or more inserted genes of another species is called

  1. Transposon
  2. Gene expression
  3. Transgenic organism
  4. Retroposons

Answer. 3. Transgenic organism

Question 75. The use of transgenic plants as biological factories for the production of special chemicals is called

  1. Molecular farming
  2. Molecular genetics
  3. Molecular mapping
  4. Dry farming

Answer. 1. Molecular farming

Question 76. Which vector is commonly used in the transfer of gene in a crop plant?

  1. Plasmids of B. subtilis
  2. Bacteriophages
  3. Ti plasmids of Agrobacterium
  4. E. coli phages

Answer. 3. Ti plasmids of Agrobacterium

Question 77. The tumor inducing capacity of Agrobacterium tumaefaciens is located in large extrachromosomal plasmid called

  1. Ti plasmid
  2. Ri plasmid
  3. Lambda phage
  4. Plasmid pBR322

Answer. 1. Ti plasmid

Question 78. Genetic engineering aims at

  1. Destroying wild gene
  2. Preserving defective gene
  3. Curing human disease by introducing new gene (hemophilia)
  4. All the above

Answer. 3. Curing human disease by introducing new gene (hemophilia)

Question 79. Taq polymerase which is used in amplification of DNA is related with

  1. Hybridoma technique
  2. PCR technique
  3. Gene cloning
  4. rDNA technology

Answer. 2. PCR technique

Question 80. DNA fragments separated by gel electrophoresis are shown. Mark the correct statement:

NEET Biology Bio Technology And Its Applications Question 80

  1. Band 3 contains more positively charged DNA molecules than band 1.
  2. Band 3 indicates more charge density than bands 1 and 2.
  3. Band 1 has longer DNA fragment than bands 2 and 3.
  4. All bands have equal length and charges but differ in base composition.

Answer. 3. Band 1 has longer DNA fragment than bands 2 and 3.

Question 81. Thermal cycle takes place in which technique?

  1. Gel electrophoresis
  2. PCR technique
  3. Centrifugation
  4. Southern blotting

Answer. 2. PCR technique

“give one commercial use of biotechnology 7 “

Question 82. Cry gene, which synthesizes crystal protein, is isolated from

  1. Bacillus thuringiensis
  2. Rhizobium
  3. Bacillus polymyxa
  4. Clostridium

Answer. 1. Bacillus thuringiensis

Question 83. Which of the following risks is associated with genetically modified food?

  1. Toxicity
  2. Allergic reaction
  3. Antibiotic resistance in microorganisms present in alimentary canal
  4. All of the above

Answer. 4. All of the above

Question 84. PCR technique is used in

  1. Production of transgenic microbes
  2. Production of genetically modified food
  3. Forensic investigation
  4. rDNA technique

Answer. 3. Forensic investigation

Question 85. TDF gene is a

  1. Gene present on X-chromosome
  2. Segment of RNA
  3. Proteinaceous factor
  4. Gene present on Y-chromosome

Answer. 4. Gene present on Y-chromosome

Question 86. BACS and YACs are

  1. Natural DNA obtained from bacteria and yeast
  2. Useful vectors for eukaryotic gene transfer
  3. Artificial DNA obtained from bacteria and yeast
  4. (2) and (3) both

Answer. 4. (2) and (3) both

Question 87. Gene therapy was first used in the treatment of

  1. Albinism
  2. Hemophilia
  3. SCID
  4. LIQID

Answer. 3. SCID

Question 88. DNA probe is used for

  1. DNA fingerprinting
  2. Detection of pathogenic bacteria
  3. Medical genetics to find whether a person carries a particular gene or not
  4. All of the above

Answer. 4. All of the above

Question 89. Bt cotton is resistant to

  1. Roundworm
  2. Flukeworm
  3. Bollworm
  4. Pinworm

Answer. 3. Bollworm

Question 90. A genetically engineered microorganism used successfully in the bioremediation of oil spills is a species of

  1. Pseudomonas
  2. Trichoderma
  3. Xanthomonas
  4. Bacillus

Answer. 1. Pseudomonas

Question 91. The first transgenic plant is

  1. Potato
  2. Tomato
  3. Tobacco
  4. Maize

Answer. 3. Tobacco

Question 92. Sheep Dolly was obtained by

  1. Cloning the udder cell (somatic cell) fused with uninucleated oocyte
  2. Cloning of gametes
  3. Tissue culture
  4. None

Answer. 1. Cloning the udder cell (somatic cell) fused with uninucleated oocyte

Question 93. E. coli are used in the production of

  1. Rifampicin
  2. LH
  3. Ecdyson
  4. Interferon

Answer. 4. Interferon

Question 94. A gaint rat is formed in the laboratory. What is the reason?

  1. Gene mutation
  2. Gene synthesis
  3. Gene manipulation
  4. Gene replication

Answer. 3. Gene manipulation

Question 95. The first cloned animal was

  1. Dolly sheep
  2. Polly sheep
  3. Molly sheep
  4. Dog

Answer. 1. Dolly sheep

Question 96. Introduction of food plants developed by genetic engineering is not desirable because

  1. Economy of developing countries may suffer
  2. These products are less tasty as compared to the already existing products
  3. This method is costly
  4. There is danger of introduction of viruses and toxins with introduced crop

Answer. 4. There is danger of introduction of viruses and toxins with introduced crop

Question 97. Which one of the following has found extensive use in genetic engineering work in plants?

  1. Bacillus coagulans
  2. Agrobacterium tumefaciens
  3. Clostridium septicum
  4. Xanthomonas citri

Answer. 2. Agrobacterium tumefaciens

Question 98. The maximum application of animal cell culture technology today is in the production of

  1. Vaccines
  2. Edible protein
  3. Insulin
  4. Interferon

Answer. 1. Vaccines

Question 99. Ti plasmid is often used for making transgenic plants. This plasmid is found in

  1. Yeast as a 2-mm plasmid
  2. Azotobacter
  3. Rhizobium of the roots of leguminous plants
  4. Agrobacterium

Answer. 4. Agrobacterium

Question 100. The cultivation of Bt cotton has been much in the news. Prefix “Bt” means

  1. “Barium-treated” cotton seeds
  2. “Bigger thread” variety of cotton with better tensile strength
  3. Produced by “biotechnology” using restriction enzymes and ligases
  4. Carrying an endotoxin gene from Bacillus thuringienisis

Answer. 4. Carrying an endotoxin gene from Bacillus thuringienisis

Question 101. An example of gene therapy is

  1. Production of injectable hepatitis B vaccine
  2. Production of vaccines in food crops such as potatoes which can be eaten
  3. Introduction of gene for adenosine deaminase in persons suffering from severe combined immunodeficiency (SCID)
  4. Production of test-tube babies by artificial insemination and implantation of fertilized eggs

Answer. 3. Introduction of gene for adenosine deaminase in persons suffering from severe combined immunodeficiency (SCID)

Question 102. Bacteria Pseudomonas is useful because of its ability to

  1. Transfer genes from one plant to another
  2. Decompose a variety of organic compounds
  3. Fix atmospheric nitrogen in the soil
  4. Produce a wide variety of antibiotics

Answer. 2. Decompose a variety of organic compounds

Question 103. Bacillus thuringiensis (Bt) strains have been used for designing novel

  1. Bioinsecticidal plants
  2. Bio-mineralization processes
  3. Biofertilizers
  4. Bio-metallurgical techniques

Answer. 1. Bioinsecticidal plants

“biotechnology example “

Question 104. Which one of the following is a correct statement?

  1. “Bt” in Bt-cotton indicates that it is a genetically modified organism produced through biotechnology.
  2. Somatic hybridization involves the fusion of two complete plant cells carrying desired genes.
  3. The anticoagulant hirudin is being produced from transgenic Brassica napus seeds.
  4. “Flavr Savr” variety of tomato has enhanced the production of ethylene which improves its taste.

Answer. 3. The anticoagulant hirudin is being produced from transgenic Brassica napus seeds.

Question 105. The approximate number of genes contained in the genome of Kalpana Chowla was

  1. 40,000
  2. 30,000
  3. 80,000
  4. 1,00,000

Answer. 2. 30,000

Question 106. In transgenics, the expression of transgene in target tissue is determined by

  1. Reporter
  2. Enhancer
  3. Transgene
  4. Promoter

Answer. 4. Promoter

Question 107. Golden rice is a promising transgenic crop. When released for cultivation, it will help in

  1. Alleviation of vitamin A deficiency
  2. Pest resistance
  3. Herbicide tolerance
  4. Producing a petrol-like fuel from rice

Answer. 1. Alleviation of vitamin A deficiency

Question 108. Agrobacterium tumefaciens contains a large plasmid, which induces tumor in plants. It is termed as

  1. Ti plasmid
  2. Ri plasmid
  3. Recombinant plasmid
  4. Shine-Dalgarno sequence

Answer. 1. Ti plasmid

Question 109. Transgenic crops are modified through genetic engineering to develop natural resistance to insect pests. Which one is a transgenic plant?

  1. Tobacco and cotton
  2. Tomato and rice
  3. Maize and sugarcane
  4. Tomato and wheat

Answer. 1. Tobacco and cotton

Question 110. Genetically engineered human insulin is called

  1. Humulin
  2. Haematin
  3. Hybriodoma
  4. Hybrid

Answer. 1. Humulin

Question 111. Abzymes are

  1. Abnormal enzymes
  2. Enzymes acting on antibodies
  3. Antibodies acting as enzymes
  4. All of these

Answer. 3. Antibodies acting as enzymes

Question 112. Hybridoma technology was developed by

  1. Taggart, 1982
  2. Prie and Saxton, 1987
  3. Vitella et. al., 1982
  4. Kohler and Milstein

Answer. 4. Kohler and Milstein

Question 113. The technique for monoclonal antibody production was discovered by

  1. Steward and Skoog
  2. Arban and Haberlan
  3. Kohler and Milstein
  4. Lister and Koach

Answer. 3. Kohler and Milstein

Question 114. The first clinical gene therapy was given for treating

  1. Both sense and anti-sense RNA
  2. A particular hormone
  3. An antifeedant
  4. A toxic protein

Answer. 1. Both sense and anti-sense RNA

Question 115. Tobacco plants resistant to nematode have been developed by the introduction of DNA that produced (in the host cells)

  1. Diabetes mellitus
  2. Chicken pox
  3. Rheumatoid arthritis
  4. Adenosine deaminase deficiency

Answer. 4. Adenosine deaminase deficiency

Question 116. Which of the following Bt crops is being grown in India by the farmers?

  1. Cotton
  2. Brinjal
  3. Soybean
  4. Maize

Answer. 1. Cotton

NEET Biology Notes – Bio Technology And Its Applications

by

BioTechnology And Its Applications

NEET Biology Notes For Biotechnological Applications In Agriculture

  • Food production can be enhanced by
    • Agro-chemical based agriculture,
    • Organic agriculture, and
    • Genetically engineered crop-based agriculture.
  • The Green Revolution resulted in increasing the food supply almost three times.
  • It refers to the great increase in the production of food grains (especially wheat and rice) that resulted in large part from the introduction of new, high yielding varieties beginning in the mid 20th century.
  • Its early dramatic successes were in Mexico and the Indian subcontinent.
  • The new varieties required large amount of chemical fertilizers and pesticides to produce high yields, raising concern about cost and potentially harmful environmental effects.
  • This demands an alternate pathway that can result in maximum yield from the fields but the use of chemicals and fertilizers is minimum, i.e., harmful effects on the environment are reduced.
  • Genetically modified organisms or GMO can be the plants, bacteria, fungi, and animals whose genes have been altered by genetic manipulation.

Read and Learn More NEET Biology Notes

NEET Biology Notes For Genetically Modified Crops

  • A transgenic crop is a crop that contains and expresses a transgene.
  • A popular term for transgenic crops is genetically modified crops or GM crops.
  • The techniques used for the production of transgenic crops offer the following two unique advantages: (a) any gene (from any organism or a gene synthesized chemically) can be used for transfer and (b) the change in genotype can be precisely controlled since only transgene is added into the crop genome.
  • In contrast, breeding activities can use only those genes which are present in the species that can be hybridized within them.
  • In addition, changes occur in all those traits for which the parents used in hybridization differ from each other.
  • When a transgene is introduced into the genome of an organism, it achieves one of the following:
    • Produces a protein (that is the product in which we are interested)
    • Produces a protein (that on its own produces the desired phenotype)
    • Modifies an existing biosynthetic pathway (so that a new end-product is obtained)
    • Prevents the expression of an existing native gene
  • Hirudin is a protein that prevents blood clotting. The gene encoding hirudin was chemically synthesized. This gene was then transferred into Brassica napus, where hirudin accumulates in seeds. Hirudin is purified and used as medicine. In this case, the transgene product itself is the product of interest.

 

NEET Biology Bio Technology And Its Applications Simplified representation of the production of hirudin from transgenic Brassica napus seeds

  • The tomato variety “Flavr Savr” presents an example where the expression of a native tomato gene has been blocked.
  • The expression of a native gene can be stopped by many different methods.
  • Fruit softening is promoted by the enzyme polygalacturonase which degrades pectin.
  • The production of polygalacturonase was blocked in the transgenic tomato variety Flavr Savr.
  • Therefore, the fruits of this tomato variety remain fresh and retain their flavor much longer than do the fruits of normal tomato varieties. In addition, the fruits have a superior taste and increased total soluble solids-these are unexpected bonus.

NEET Biology Notes For Genetically Modified Food

  • Food prepared from the produce of genetically modified (transgenic) crops is called genetically modified food or, in short, GM food. GM food differs from the food prepared from the produce of conventionally developed varieties mainly in the following aspects.
    • Firstly, GM food contains the protein produced by the transgene in question, e.g., cry protein in case of insect-resistant varieties.
    • Secondly, it contains the enzyme produced by the antibiotic resistance gene that was used during gene transfer by genetic engineering.
    • Finally, it contains the antibiotic resistance gene itself.
  • It has been argued that the above features of GM foods can lead to the following problems when they are consumed.
    • Firstly, the transgene product may cause toxicity and/or produce allergies.
    • Secondly, the enzyme produced by the antibiotic resistance gene can cause allergies, since it is a foreign protein.
    • Finally, the bacteria present in the alimentary canal of humans can take up the antibiotic resistance gene that is present in the GM food.
    • These bacteria would then become resistant to the concerned antibiotic.
    • As a result, these bacteria can become difficult to manage.
  • Scientists involved in the production of transgenic crops are addressing these concerns.
    • Efforts are being made to use other genes in place of antibiotic resistance genes.
    • The toxic and allergenic actions of the transgene product can be adequately examined by detailed assays using suitable animal models.

Biological Transcription

NEET Biology Notes For Biotechnological Applications GM Products: Benefits And Controversies

Benefits

Crops

  • Enhanced taste and quality.
  • Reduced maturation time.
  • Increased nutrients, yields, and stress tolerance.
  • Improved resistance to disease, pests, and herbicides.
  • New products and growing techniques.

Animals

  • Increased resistance, productivity, hardiness, and feed efficiency.
  • Better yields of meat, eggs, and milk.
  • Improved animal health and diagnostic methods.

Environment

  • “Friendly” bioherbicides and bioinsecticides.
  • Conservation of soil, water, and energy.
  • Bioprocessing for forestry products.
  • Better natural waste management.
  • More efficient processing.

Society

  • Increased food security for growing populations.

Controversies in Terms of Safety

  • Potential human health impact: Allergens, transfer of antibiotic resistance markers, and unknown effects.
  • Potential environmental impact: Unintended transfer of transgenes through cross-pollination, unknown effects on other organisms (e.g., soil microbes), and loss of flora and fauna biodiversity.

NEET Biology Notes For Biotechnological Applications BT Cotton

  • DNA technology makes it possible to locate the genes that produce Bt proteins lethal to insects and transfer the genes into crop plants.
  • First, scientists identify a strain of Bt that kills the targeted insect.
  • Then they isolate the gene that produces the lethal protein.
  • This gene is removed from the Bt bacterium and a gene conferring resistance to a chemical (usually antibiotic or herbicide) is attached (which proves useful in later steps).
  • The Bt gene with the resistance gene attached is inserted in plant cells.
  • These modified or genetically transformed cells are then grown into a complete plant by tissue culture.
  • The modified plant produces the same lethal protein as produced by the Bt bacteria because plants now have the same gene.
  • B. thuringiensis form protein crystals during a particular phase of their growth.
  • These crystals contain a toxic insecticidal protein.
  • Why does this toxin not kill the Bacillus? Actually, the Bt toxin protein exists as inactive protoxin; but once an insect ingests the inactive toxin, it is converted into an active form of toxin due to the alkaline pH of the gut which solubilizes the crystals.
  • The activated toxin binds to the surface of midgut epithelial cells and creates pores that cause cell swelling and lysis and, eventually, cause the death of the insect.
  • Bt is not harmful to humans, other mammals, birds, fish, or beneficial insects.
  • Specific Bt toxin genes were isolated from B. thuringiensis and incorporated into several crop plants such as cotton.
  • The choice of genes depends upon the crop and the targeted pest, as most Bt toxins are insect-group specific.
  • The toxin is coded by a gene named cry. There are a number of them. For example, the proteins encoded by genes cry I Ac and cry II Ab control the cotton bollworm and that by cry I Ab control corn borer.

NEET Biology Bio Technology And Its Applications Cotton boll

” short notes on biotechnology “

  • Although Bt genes have been introduced into tobacco, tomatoes, cotton, and other broadleaf plants, gene transfer technology for corn is a recent achievement.
  • The development of corn plants expressing Bt proteins requires substantial changes in the Bt genes, including the creation of synthetic versions of the genes, rather than the microbial Bt gene itself.

NEET Biology Notes For Biotechnological Applications Pest – Resistant Plants

  • Root-knot nematode is the most economically important group of plant-parasitic nematodes worldwide. It attacks nearly every food and fiber crop grown (about 2000 plant species in all).
  • Nematodes invade plant roots. By feeding on the roots’ cells, they cause the roots to grow large and form galls, or knots, damaging the crop and reducing its yield.
  • The most cost-effective and sustainable management tactic for preventing root-knot nematode damage and reducing growers’ losses is to develop resistant plants that prevent the nematode from feeding on the roots. Because root-knot nematode resistance does not come naturally in most crops, bioengineering is required. Four common root-knot nematode species (mainly Meloidegyne incognitia) account for 95% of all infestations in agricultural land.
  • By discovering a root-knot nematode parasitism gene that is essential for the nematode to infect crops, scientists have developed a resistance gene effective against all four species.
  • Using a technique called RNA interference (RNAi), researchers have effectively turned nematode’s biology against itself.
  • They genetically modified Arabidopsis, a model plant, to produce double-stranded RNA (dsRNA) to knock out the specific parasitism gene in the nematode when it feeds on the plant roots.
  • RNAi takes place in all eukaryotic organisms as a method of cellular defense.
  • This method involves the silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents the translation of the mRNA (silencing).
  • The source of this complementary RNA could be an infection by viruses having RNA genomes or mobile genetic elements (transposons) that replicate via an RNA intermediate.
  • Using Agrobacterium vectors, nematode-specific genes were introduced into the host plant.
  • The introduction of DNA was such that it produced both sense and anti-sense RNA in the host cells.

NEET Biology Bio Technology And Its Applications Host plant generated dsRNA

  • These two RNAS being complementary to each other formed a dsRNA that initiated RNAi and, thus, silenced the specific mRNA of the nematode.
  • The consequence was that the parasite could not survive in a transgenic host expressing siRNA.
  • The transgenic plant, therefore, got itself protected from the parasite.
  • This knocked out the parasitism gene in the nematode and disrupted its ability to infect plants. (No natural root-knot resistance gene has this effective range of root-knot nematode resistance.)
  • Efforts have been directed primarily at understanding the molecular tools the nematode uses to infect plants.
  • This is a prerequisite for bioengineering durable resistance to these nematodes in crop plants.

Biological Transcription

NEET Biology Notes For Biotechnological Applications Biotechnological Application In Medicine

Therapeutic Agents

  • Proteins with potential as pharmaceutical agents are produced by using genetically engineered organisms.
  • Enzymes have also been used for this purpose, e.g., DNase I and alginate lyase have been used in aerosols. Some known examples are as follows:
    • Human growth hormone obtained from E. coli is used for the treatment of dwarfness.
    • Chorionic gonadotropin hormone produced by genetic engineering is used for the treatment of infertility.
    • Interferons produced by E. coli are commercially used for the treatment of viral infections and cancer. These were first obtained through DNA recombinant technique by Charles Weisman in 1980. He inserted the gene for interferon production in E. coli.
    • Interleukins produced by E. coli are used for stimulating immunity system.
    • Tissue plasminogen activator (tPA)-an enzyme is used for dissolving blood clot after heart attack and stroke.
    • Antihemophilic human factor VIII is used by people with hemophilia to prevent and control bleeding or to prepare them for surgery.
    • Platelet-derived growth factor produced by recombinant DNA technology is useful for stimulating wound healing.
    • Penicillin G acylase is also produced by genetic engineering. This enzyme is used for converting penicillin into 6-aminopenicillin acid for the formation of new antibiotics.

Genetically Engineered Insulin

  • Since the discovery of insulin by Banting and Best (in 1921) and its use for the treatment of diabetes, it was derived from the pancreatic glands of abattoir animals.
  • This hormone, produced and secreted by the beta cells of the pancreas islets of Langerhans, regulates the use and storage of food, particularly carbohydrates.
  • Although bovine and porcine insulin are similar to human insulin, their composition is slightly different. It, therefore, causes adverse effects due to regular injection, being a foreign substance.
  • This observation led to the synthesis of human insulin which is chemically identical to its naturally-produced counterpart.
  • Insulin consists of 51 amino acids forming two short polypeptide chains: chain A with 21 amino acids and chain B with 30 amino acids.
  • The two chains are linked by disulfide bond. In animals, including humans, insulin occurs as proinsulin.
  • It is made of chain A, chain B, and chain C (30 amino acids). As the insulin matures, chain C is removed.
  • The genetic engineering of insulin begins with the identification and separation of DNA sequences coding for chain A and chain B.
  • This was found to be present at the top of the short arm of the 11th chromosome.
  • It contains 153 nucleotides-63 nucleotides for chain A and 90 nucleotides for chain B.
  • These sequences were introduced into the plasmid (pBR322) of E. coli-common human colon bacterium.
  • It is said to be the factory used in the genetic engineering of insulin.
  • In E. coli, B-galactosidase controls the transcription of these genes. Therefore, the insulin gene needs to be tied to this enzyme.
  • The protein formed by E. coli consists partly of B-galactosidase joined to either A or B chain of insulin.
  • These are then extracted from ẞ-galactosidase fragment and purified.
  • The two chains are mixed and reconnected in a reaction that forms disulfide bridges resulting in pure humulin–the synthetic human insulin.

NEET Biology Bio Technology And Its Applications Proteins with therapeutic and industrial value that have been produced in the milk

NEET Biology Notes For Biotechnological Applications Gene Therapy

  • Much attention has been focused on the so-called genetic metabolic diseases in which a defective gene causes an enzyme to be either absent or ineffective in catalyzing a particular metabolic reaction effectively.
  • A potential approach to the treatment of genetic disorders in man is gene therapy.
  • This is a technique in which the absent or faulty gene is replaced by a working gene, so that the body can make the correct enzyme or protein and, consequently, eliminate the root cause of the disease.
  • The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency.
  • This enzyme is crucial for the immune system to function.
  • The disorder is caused due to the deletion of the gene for adenosine deaminase.
  • In some children, ADA deficiency can be cured by bone marrow transplantation; in others, it can be treated by enzyme replacement therapy, in which functional ADA is given to the patient by injection.
  • But the problem with both these approaches is that they are not completely curative.
  • As a first step towards gene therapy, lymphocytes from the blood of the patient are grown in a culture outside the body.
  • A functional ADA cDNA (using a retroviral vector) is then introduced into these lymphocytes, which are subsequently returned to the patient.
  • However, as these cells are not immortal, the patient requires periodic infusion of such genetically engineered lymphocytes.
  • However, if the gene isolated from marrow cells producing ADA is introduced into cells at early embryonic stages, it could be a permanent cure.
  • Before the treatment of a genetic disease begins, an accurate diagnosis of the genetic defect needs to be made.
  • It is here that biotechnology is also likely to have a great impact in the near future.
  • Genetic engineering research has produced a powerful tool for pinpointing specific diseases rapidly and accurately.
  • Short pieces of DNA called DNA probes can be de- signed to stick very specifically to certain other pieces of DNA.
  • The technique relies upon the fact that complementary pieces of DNA stick together.
  • DNA probes are more specific and have the potential to be more sensitive than conventional diagnostic methods. It should be possible in the near future to distinguish between defective genes and their normal counterparts. (This is an important development.)

NEET Biology Notes For Biotechnological Applications Biological Transcription

Molecular Diagnosis

  • For the effective treatment of a disease, early diagnosis and understanding its pathophysiology are very important.
  • Using the conventional methods of diagnosis (serum and urine analysis, etc.), early detection is not possible.
  • Recombinant DNA technology, polymerase chain reaction (PCR), and enzyme linked immuno-sorbent assay (ELISA) are some of the techniques that serve the purpose of early diagnosis.
  • The presence of a pathogen (bacteria, virus, etc.) is normally suspected only when the pathogen has produced a disease symptom.
  • By this time, the concentration of pathogen is already very high in the body.
  • However, very low concentration of a bacteria or virus (at a time when the symptoms of the disease are not yet visible) can be detected by the amplification of its nucleic acid by PCR, which is now routinely used to detect HIV in suspected AIDS patients.
  • It is being used to detect mutations in genes in suspected cancer patients too.
  • It is a powerful technique to identify many other genetic disorders.
  • DNA is usually isolated from white blood cells and has to be cut into smaller pieces to be analyzed.
  • This is accomplished by restriction enzymes. Eco RI (a restriction enzyme from E. coli) will cut DNA wherever the sequence “GAA TTC” appears.
  • An exposure to this enzyme results in the DNA being chopped into millions of fragments (called restriction fragments) of varying size.
  • Once cut, the DNA is loaded into a well on one end of a slab of gel.
  • The fragments are then separated according to size by electrophoresis.
  • As electric current passes through the gel, the fragments move according to size.
  • Bigger fragments stay close to the origin and smaller fragments move farther down the length of the gel.
  • The DNA is then denatured (by exposure to alkaline solutions) to render the DNA single stranded (instead of the natural double-stranded form).
  • Since the gel is difficult to handle, the DNA is transferred to a nitro cellulose paper to create a Southern blot (named after the researcher who developed the procedure).
  • The DNA probe which is radioactively labeled (or fluorescently labeled) is then applied to the Southern blot.
  • Since the probe is also single-stranded, it will seek the single-stranded DNA fragments that are complementary, and undergo hybridization.
  • The excess probe is washed out and only the bound probe will remain on the Southern blot paper.
  • This is then laid on an X-ray film.
  • The radioactive probe will leave bands on the X-ray film.
  • Depending on the type of probe used, there can be hundreds of bands (much like barcodes) or only a few bands present on the X-ray film.
  • By having several wells on the end of the gel, several samples can be loaded and DNA fragments in the corresponding lanes can be analyzed concurrently.
  • By running control samples, with known DNA fragment sizes, on the same gel with patient samples, it is possible to identify changes in the size of a DNA fragment and, therefore, the change in a specific gene.
  • Since each step takes about a day and since samples are batched, the procedure ordinarily takes one to two weeks to complete.
  • ELISA is based on the principle of antigen-antibody interaction. Infection by pathogen can be detected either by the presence of antigens (proteins, glycoproteins, etc.) or by detecting the antibodies synthesized against the pathogen.

” importance of biotechnology “

NEET Biology Notes For Biotechnological Applications Transgenic Animal

  • There are various definitions for the term “transgenic animal.”
  • A transgenic animal is one whose genome has been changed to carry genes from other species.
  • The nucleus of all cells in every living organism contains genes made up of DNA.
  • These genes store information that regulates how our bodies form and function.
  • Genes can be altered artificially, so that some characteristics of an animal are changed.
  • For example, an embryo can have an extra, functioning gene from another source artificially introduced into it, or it can have a gene introduced which can knock out the functioning of another particular gene in the embryo.
  • Animals that have their DNA manipulated in this way are known as transgenic animals.
  • The majority of transgenic animals produced so far are mice the animal that pioneered the technology.
  • The first successful transgenic animal was a mouse. A few years later, it was followed by rabbits, pigs, sheep, and cattle.

How are Transgenic Animals Produced?

  • To date, there are three basic methods of producing transgenic animals:
    • DNA microinjection
    • Retrovirus-mediated gene transfer
    • Embryonic stem cell-mediated gene transfer
  • Gene transfer by microinjection is the predominant method used to produce transgenic farm animals.
  • Since the insertion of DNA results in a random process, transgenic animals are mated to ensure that their offsprings acquire the desired transgene.
  • However, the success rate of producing transgenic animals individually by these methods is very low and it may be more efficient to use cloning techniques to increase their numbers.
  • For example, gene transfer studies revealed that only 0.6% of transgenic pigs were born with a desired gene after 7,000 eggs were injected with a specific transgene.

How do Transgenic Animals Contribute to Human Welfare?

  • The benefits of these animals to human welfare can be grouped into the following areas:
    • Agriculture
    • Medicine
    • Industry
  • The following examples are not intended to be complete but only to provide a sampling of the benefits.

NEET Biology Notes For Biotechnological Applications Agricultural Applications

  • Breeding: Farmers have always used selective breeding to produce animals that exhibit desired traits (e.g., increased milk production and high growth rate). Traditional breeding is a time consuming, difficult task. When technology using molecular biology was developed, it became possible to develop traits in animals in a shorter time and with more precision. In addition, it offers the farmer an easy way to increase yields.
  • Quality: Transgenic cows exist that produce more milk or milk with less lactose or cholesterol, pigs and cattle that have more meat on them, and sheep that grow more wool. In the past, farmers used growth hormones to spur the development of animals; but this technique was problematic, especially since the residue of the hormones remained in the animal product.
  • Disease resistance: Scientists are attempting to produce disease-resistant animals, such as influenza-resistant pigs, but a very limited number of genes are currently known to be responsible for resistance to dis- eases in farm animals.

Medical Applications

  • Xenotransplantation: Patients die every year for the lack of a replacement heart, liver, or kidney. For example, about 5,000 organs are needed each year in the United Kingdom alone. Transgenic pigs may provide the transplant organs needed to alleviate the shortfall. Currently, xenotransplantation is hampered by a pig protein that can cause donor rejection but research is underway to remove the pig protein and replace it with a human protein.
  • Nutritional supplements and pharmaceuticals: Products such as insulin, growth hormone, and blood anti-clotting factors may soon be or have already been obtained from the milk of transgenic cows, sheep, or goats. Research is also underway to manufacture milk through transgenics for the treatment of debilitating diseases such as phenylketonuria (PKU), hereditary emphysema, and cystic fibrosis.
  • In 1997, the first transgenic cow, Rosie, produced hu- man protein-enriched milk (2.4 g/L). This transgenic milk is a more nutritionally balanced product than the natural bovine milk and can be given to babies or the elderly with special nutritional or digestive needs. Rosie’s milk contains the human gene a-lactalbumin.
  • Vaccine safety: Transgenic mice are being developed for use in testing the safety of vaccines before the vaccines are used on humans. These mice are being used to test the safety of the polio vaccine. If successful and found to be reliable, they can replace the use of monkeys to test the safety of batches of the vaccine.

NEET Biology Notes For Biotechnological Applications Biological Transcription

Industrial Applications

  • In 2001, two scientists at Nexia Biotechnologies in Canada spliced spider genes into the cells of lactating goats.
  • The goats began to manufacture silk along with their milk and secrete tiny silk strands from their body by the bucketful.
  • By extracting polymer strands from the milk and weaving them into thread, scientists can create a light, tough, flexible material that can be used in applications such as military uniforms, medical microsutures, and tennis racket strings.
  • Toxicity-sensitive transgenic animals have been produced for chemical safety testing.
  • Microorganisms have been engineered to produce a wide variety of proteins, which in turn can produce enzymes that can speed up industrial chemical reactions. The anthrax bacterium is sent through letters after September 2001.
  • Mass-produced pathogens or their toxins are delivered either as powder or in the form of spray, using a variety of delivery devices.
  • Bioweapons are low-cost weapons. These cause far more casualties than chemical or conventional weapons. Bioweapon agents are invisible and extremely difficult to detect.
  • These features make bioweapon agents very convenient for use by terrorists and even governments. (Both have used them on a limited scale.)
  • The possible defenses against bioweapons include the use of respirator or gas mask, vaccination, administration of appropriate antibiotics, and decontamination. In addition, sensitive detection systems should be developed to control and minimize damage.

NEET Biology Notes For Biotechnological Applications Bioethics

  • Ethics include a set of standards by which a community regulates its behavior and decides as to which activity is legitimate and which is not.
  • Therefore, bioethics may be viewed as a set of standards that may be used to regulate our activities in relation to the biological world.
  • Biotechnology, particularly recombinant DNA tech- nology, is focused on exploiting the biological world in ways that are usually unprecedented.
  • Therefore, biotechnology has been labeled variously, ranging from “unnatural” to “detrimental” to “biodiversity.”
  • The major bioethical concerns pertaining to biotechnology are as follows:
    • The use of animals in biotechnology causes great suffering to them.
    • When animals are used for the production of pharmaceutical proteins, they are virtually reduced to the status of a “factory.”
    • Introduction of a transgene from one species into another species violates the “integrity of species.”
    • The transfer of human genes into animals (and vice versa) dilutes the concept of “humanness.”
    • Biotechnology is disrespectful to living beings; it only exploits them for the benefit of human be- ings.
    • Biotechnology may pose unforeseen risks to the environment, including risk to biodiversity.
  • These arguments may seem quite attractive.
  • It may be pointed out that biotechnology usually does only what was being done before.
  • However, biotechnologies do these things on a much larger scale and at a much faster rate.
  • Each society has to evaluate for itself the validity of these and other arguments related to biotechnology.
  • It also has to decide the kinds of activities that it considers acceptable and those that it does not.
  • Going beyond the morality of such issues, the biological significance of such things is also important.
  • Genetic modification of organisms can have unpredictable results when such organisms are introduced into the ecosystem.
  • Therefore, the Indian Government has set up organizations such as GEAC (Genetic Engineering Approval Committee), which will make decisions regarding the validity of GM research and the safety of introducing GM-organisms for public services.
  • The modification/usage of living organisms for public services (as food and medicine sources, for example) has also created problems with patents granted for the same.

NEET Biology Notes For Biotechnological Applications Biopatent

  • A patent is a right granted by a government to an inventor to prevent others from the commercial use of his invention.
  • A patent is granted for (a) an invention (including a product), b) an improvement in an earlier invention, (c) the process of generating a product, and (d) a concept or design.
  • Initially, patents were granted for industrial inventions, etc.
  • But at present, patents are being granted for biological entities and for products derived from them; these patents are called biopatents.
  • Primarily, industrialized countries such as the USA, Japan, and the members of European Union are awarding biopatents.
  • Biopatents are awarded for the following:
    • Strains of microorganisms
    • Cell lines
    • Genetically modified strains of plants and animals
    • DNA sequences
    • The proteins encoded by DNA sequences
    • Various biotechnological procedures
    • Production processes
    • Products
    • Product applications
  • There has been a great deal of opposition from the various social groups to the patenting of life forms.
  • The nature of these objections is mainly ethical and political.
  • The arguments in favor of biopatents are primarily of increased economic growth.
  • Many biotechnology patents are very broad in their coverage.
  • For example, one patent covers “all transgenic plants of Brassica family.”
  • Such broad patents are considered morally unacceptable and fundamentally inequitable, since these would enable financially powerful corporations to acquire monopoly control over biotechnological processes.
  • They may, in the end, even come to control the direction of agricultural research, including plant breeding.
  • Such a position would pose a threat to global food security.
  • Many organizations and multinational companies exploit and/or patent biological resources, or bioresources, of other nations without proper authorization from the countries concerned; this is known as biopiracy.
  • Industrialized nations are rich in technology and financial resources but poor in biodiversity and traditional knowledge related to the utilization of bioresources.
  • In contrast, developing nations are poor in technology and financial resources, but are rich in biodiversity and traditional knowledge related to bioresources.
  • Biological resources (or bioresources) include all those organisms that can be used to derive commercial benefits.
  • Traditional knowledge related to bioresources is the knowledge developed by various communities over long periods of history regarding the utilization of bioresources, e.g., the use of herbs, etc., as drugs.
  • Often, this traditional knowledge can be exploited to develop modern commercial processes.
  • The traditional knowledge suggests the direction to be followed, and saves considerable time, effort, and expenditure for their commercialization.
  • Institutions and companies of industrialized nations are collecting and exploiting the bioresources as follows:
    • They are collecting and patenting the genetic resources themselves. For example, a patent granted in the USA covers the entire basmati rice germplasm indigenous to our country.
    • The bioresources are being analyzed for the identification of valuable biomolecules. (A bio-molecule is a compound produced by a living organism.) The biomolecules are then patented and used for commercial activities.
    • Useful genes are isolated from the bioresources and patented. These genes are then used to generate commercial products.
    • The traditional knowledge related to bioresources is utilized to achieve these objectives. In some cases, the traditional knowledge itself may be the subject of patent.
  • A West African plant, Pentadiplandra brazzeana, produces a protein called brazzein, which is approximately 2000 times as sweet as sugar.
  • In addition, brazzein is a low-calorie sweetener.
  • Local people have known and used the super-sweet berries of this plant for centuries.
  • But the protein brazzein was patented in the USA.
  • Subsequently, the gene encoding brazzein was also isolated, sequenced, and patented in the USA.
  • It is proposed to transfer the brazzein gene into maize and express it in maize kernels.
  • These kernels will then be used for the extraction of brazzein.
  • This development can have serious implications for countries exporting large quantities of sugar.
  • Bioresources of the developing world have always been commercially exploited by the industrialized nations without an adequate compensation to the developing world.
  • This exploitation has dramatically increased in pace with the development of powerful analytical tools and techniques.
  • There has been a growing realization of this injustice and demands are being made for adequate compensation and benefit sharing.
  • Some nations are developing comprehensive laws to prevent unauthorized exploitation of their bioresources and traditional knowledge.
  • The Indian Parliament has recently cleared the second amendment of the Indian Patents Bill, which takes such issues into consideration, including patent terms, emergency provisions, and research and development initiative.

NEET Biology Bio-Technology And Its Applications Multiple Question and Answers

Question 1. Which one of the following can be used as a permanent cure for ADA deficiency?

  1. Bone marrow transplantation on detection of disorder in adults.
  2. Enzyme replacement therapy at any point in life.
  3. Both (1) and (2).
  4. Gene therapy at early embryonic stages.

Answer. 4. Gene therapy at early embryonic stages.

Question 2. Which one of the following is a transgenic product useful for the treatment of hemophilia?

  1. Factor VIII
  2. Antithrombin II
  3. α-1-antitrypsin
  4. Lysostaphin

Answer. 1. Factor VIII

” application of biotechnology”

Question 3. Who is responsible for obtaining interferons through re- combinant DNA technique?

  1. A.R. Bounting
  2. Eli Lily
  3. Charles Weissmann
  4. A. Tiselius

Answer. 3. Charles Weissmann

Question 4. Select the incorrect statement:

  1. RNAi silencing takes place in all eukaryotic organ- isms as a method of cellular defense.
  2. RNAi requires silencing of mRNA by binding of complementary ssDNA molecule.
  3. Complementary nucleic acid could be from mobile genetic elements (transposons).
  4. Ti plasmid with nematode-specific genes has been used in RNAi.

Answer. 2. RNAi requires silencing of mRNA by binding of complementary ssDNA molecule.

Question 5. Which gene controls the transcription of chain A and chain B required for humulin synthesis in E. coli?

  1. B-Lactamase
  2. B-Galactosidase
  3. Polygalacturonase
  4. Chitinase

Answer. 2. B-Galactosidase

Question 6. Transgenic Brassica napus has been used for the synthesis of

  1. Hirudin
  2. Heparin
  3. Polygalacturonase
  4. Cry protein

Answer. 1. Hirudin

Question 7. Which genes encode the protein to control bollworm infection in cotton plants?

  1. Cry II Ab
  2. Cry I Ac
  3. Both (1) and (2)
  4. Amp

Answer. 3. Both (1) and (2)

Question 8. Which is incorrect with respect to GM food?

  1. It contains the protein produced by the transgene in question.
  2. GM food contains antibiotic resistance gene itself.
  3. The enzyme produced by antibiotic resistance gene will not cause allergies.
  4. The bacteria in gut of humans could take by antibiotic resistance gene.

Answer. 3. The enzyme produced by antibiotic resistance gene will not cause allergies.

Question 9. Golden rice-a transgenic variety of rice is principally richer than normal rice in

  1. Cry I Ab
  2. Hirudin
  3. TPA
  4. B-carotene

Answer. 4. B-carotene

Question 10. Southern blotting cannot be performed without

  1. Restriction endonucleases
  2. Agarose
  3. Monoclonal antibodies
  4. Both (1) and (2)

Answer. 4. Both (1) and (2)

Question 11. Plants, bacteria, fungi, and animals whose genes have been altered by manipulation are called genetically modified organisms (GMO). Which of the following statement is not applicable to GM plants?

  1. Reduced reliance on chemical pesticides.
  2. Prevent early exhaustion of fertility of soil.
  3. Crops less tolerant to abiotic stress (cold, drought, salt, and heat).
  4. Enhanced nutritional value of food.

Answer. 3. Crops less tolerant to abiotic stress (cold, drought, salt, and heat).

Question 12. In case of Bacillus thuringiensis, Bacillus itself is not killed by toxic protein crystals produced by it because

  1. Bt toxin protein is not produced in Bacillus
  2. Bt toxin protein is produced in very less amount in Bacillus
  3. Bt toxin exists as inactive toxin
  4. Bt toxin cannot cause any damage to Bacillus

Answer. 3. Bt toxin exists as inactive toxin

Question 13. Bt toxin kills the insect by

  1. Blocking nerve conduction
  2. Damaging the surface of trachea
  3. Creating pores in the tracheal system
  4. Creating pores in the mid gut

Answer. 4. Creating pores in the mid gut

Question 14. Which of the following cry gene codes for the protein which can control the corn borer effectively?

  1. cry I Ac
  2. cry II Ab
  3. cry I Ab
  4. cry II Ac

Answer. 3. cry I Ab

Question 15. RNA interference (RNAi) technique has been devised to protect plants from nematode. In this technique, the mRNA of nematode is silenced by _______ produced by the host plant.

  1. dsDNA
  2. ssDNA
  3. dsRNA
  4. Target proteins

Answer. 3. dsRNA

Question 16. Which of the following peptide chain is removed during the maturation of pro-insulin into insulin?

  1. A peptide
  2. B peptide
  3. C peptide
  4. A and C peptides

Answer. 3. C peptide

Question 17. Eli Lilly, an American company, prepared two DNA se- quences corresponding to A and B chains of human insulin and introduced them in the plasmids of E. coli to produce insulin chains. Chains A and B were produced separately, extracted, and combined by creating

  1. Peptide bonds
  2. Ionic bonds
  3. H-bonds
  4. Disulfide bonds

Answer. 4. Disulfide bonds

Question 18. The first clinical gene therapy was given in 1990 to a 4-year old girl with which of the following enzyme deficiency?

  1. Adenosine deaminase
  2. Tyrosine oxidase
  3. Monamine oxidase
  4. Glutamate dehydrogenase

Answer. 1. Adenosine deaminase

Question 19. Which of the following could be a permanent cure for the treatment of severe combined immunodeficiency (SCID)?

  1. Bone marrow transplantation
  2. Enzyme replacement therapy
  3. Both (1) and (2)
  4. Gene therapy

Answer. 4. Gene therapy

Question 20. Which of the following technique is being used to detect mutations in genes in suspected cancer patients?

  1. PCR
  2. ELISA
  3. Blood analysis
  4. PAGE

Answer. 1. PCR

Question 21. Animals that have had their DNA manipulated to possess and express an extra gene are known as

  1. Foreign animals
  2. Superior animals
  3. Transgenic animals
  4. Intergenic animals

Answer. 3. Transgenic animals

Question 22. About 95% of all existing transgenic animals are

  1. Rabbits
  2. Pigs
  3. Cows
  4. Mice

Answer. 4. Mice

Question 23. Today, transgenic models exist for many human diseases which includes

A. Cancer

B. Cystic fibrosis

C. Rheumatoid arthritis

D. Alzheimer’s disease

  1. (A) and (C) only
  2. (B) and (C) only
  3. (A), (B), and (C) only
  4. All of these

Answer. 4. All of these

Question 24. Which of the following is not a true statement with respect to Bt cotton?

  1. Bt toxin is produced by a bacterium Bacillus thuringiensis.
  2. It is an example of biopesticide.
  3. Bt toxin gene has been cloned in plants to provide resistance to insects.
  4. Bt cotton could decrease the amount of pesticide used.

Answer. 3. Bt toxin gene has been cloned in plants to provide resistance to insects.

Question 25. How many recombinant therapeutics have been approved for human use all over the world?

  1. 12
  2. 30
  3. 20
  4. 18

Answer. 2. 30

Question 26. Which of the following techniques serve the purpose of early diagnosis?

A. Recombinant DNA technology

B. PCR

C. ELISA

  1. (A) only
  2. (A) and (C) only
  3. (A) and (B) only
  4. All of these

Answer. 4. All of these

Question 27. Which of the following technique is based upon the principle of antigen-antibody interaction?

  1. PCR
  2. ELISA
  3. Recombinant DNA technology
  4. RNA interference

Answer. 2. ELISA

Question 28. Which of the following transgenic protein product has been used to treat emphysema?

  1. α-l-Antitrypsin
  2. α-Lactalbumin
  3. Cry protein
  4. C-peptide

Answer. 1. α-l-Antitrypsin

Question 29. How many varieties of rice have been estimated to be present in India?

  1. 2000
  2. 20,000
  3. 2,00,000
  4. 20,00,000

Answer. 3. 2,00,000

Question 30. The use of bioresources by multinational companies and other organizations without proper authorization from the countries and people concerned without compensatory payment is called

  1. Bioethics
  2. Biopiracy
  3. Bioterror
  4. Bioweapon

Answer. 2. Biopiracy

Question 31. Amongst the following, which characteristic is not applicable to Bt cotton?

  1. Bt is the abbreviated term for botulinum toxin.
  2. Such cotton is resistant to armyworms and beetles.
  3. The toxin is activated in the body of the insect.
  4. The toxin is coded by a gene called “cry.”

Answer. 1. Bt is the abbreviated term for botulinum toxin.

Question 32. Which biotechnology company is credited with the synthesis of genetically engineered human insulin for the first time?

  1. Celera genomics
  2. Cipla
  3. Eli Lily
  4. Ranbaxy

Answer. 3. Eli Lily

Question 33. Functional ADA cDNA can be introduced into the cells of the patient receiving gene therapy by using a vector constituted by

  1. E. coli
  2. Reovirus
  3. Retrovirus
  4. Agrobacterium

Answer. 3. Retrovirus

Question 34. Which variety of rice was patented by a US company even though the highest number of varieties of this rice is found in India?

  1. Shamati Sonara
  2. Co-667
  3. Basmati
  4. Lerma Roja

Answer. 3. Basmati

Question 35. Which step has the Government of India taken to cater to the requirement of patent terms and other emergency provisions in this regard?

  1. Biopiracy Act
  2. Indian Patents Bill
  3. RTI Act
  4. Negotiable Instruments Act

Answer. 2. Indian Patents Bill

Question 36. What is another term used for GMO (genetically modified organisms)?

  1. Cybrid organisms
  2. Genomorphic organisms
  3. Transgenic organisms
  4. Conjoint twins

Answer. 3. Transgenic organisms

Question 37. Transgenic models can be used to investigate several human diseases such as

  1. Alzheimer’s disease
  2. Cystic fibrosis
  3. Carcinoma
  4. All of these

Answer. 4. All of these

Question 38. Which GMO is now being developed in order to be used in testing the safety of polio vaccines before they are used in humans?

  1. Transgenic sheep
  2. Transgenic cow
  3. Transgenic mice
  4. Transgenic viruses

Answer. 3. Transgenic mice

Question 39. Which method of cellular defense is common in all eukaryotic organisms?

  1. RNA interference
  2. Reverse transcription
  3. VNTR
  4. Phagocytosis

Answer. 1. RNA interference

Question 40. “Silencing” of mRNA molecule in order to control the production of a harmful protein has been used in the protection of plants from

  1. Nematodes
  2. Beetles
  3. Mosquitoes
  4. Flies

Answer. 1. Nematodes

Question 41. Mark the odd one with respect to the advantages of genetically modified plants:

  1. Production of food with better nutritional value.
  2. Decrease in post harvest losses.
  3. Decreased dependence on fertilizers.
  4. Decreased usage of minerals.

Answer. 4. Decreased usage of minerals.

Question 42. In which disease has the advancement of genetic engineering still not been used as clinical cure?

  1. Emphysema
  2. Cystic fibrosis
  3. Phenylketonuria
  4. Anencephaly

Answer. 4. Anencephaly

biotechnology notes

Question 43. Which substance is tested in case of toxicity/safety testing using transgenic animals?

  1. Chemicals
  2. Pathogen
  3. The amount of DNA in the cell
  4. The amount of tolerable radiation levels of an organism

Answer. 1. Chemicals

Question 44. Which step proved to be the main challenging obstacle in the production of human insulin by genetic engineering?

  1. Removal of C-peptide from active insulin.
  2. Getting insulin assembled into a mature form.
  3. Addition of C-peptide to pro-insulin.
  4. Splitting A and B polypeptide chains.

Answer. 2. Getting insulin assembled into a mature form.

Question 45. What is the disadvantage of using processed insulin (from pig pancreas) in diabetic patients?

  1. It leads to hypercalcaemia.
  2. It may cause allergic reactions.
  3. It is expensive.
  4. It can lead to mutations in human recipients.

Answer. 2. It may cause allergic reactions.

Question 46. Why are repeated transfusions of genetically engineered cells required in SCID patients?

  1. The transfused cells have limited lifespan.
  2. The introduced gene is mutated.
  3. The enzyme required is degraded after 20 days of transfusion.
  4. Both (2) and (3).

Answer. 1. The transfused cells have limited lifespan.

Question 47. Which Indian plants have either been patented or attempts have been made to patent them by the Western nations for their commercial use?

  1. Basmati rice
  2. Turmeric
  3. Neem
  4. All of these have been targeted

Answer. 4. All of these have been targeted

Question 48. Why is insulin usually not administered orally to a diabetic patient?

  1. Insulin is bitter in taste.
  2. Insulin is a peptide.
  3. Insulin will lead to a sudden decrease in blood sugar if given orally.
  4. Insulin leads to peptic ulcer orally.

Answer. 2. Insulin is a peptide.

Question 49. Which technique would you expect to be completely curative in SCID?

  1. Gene therapy in adult stage.
  2. Gene therapy in embryonic stage.
  3. Bone marrow transplantation.
  4. Enzyme replacement therapy.

Answer. 2. Gene therapy in embryonic stage.

Question 50. A doctor while operating on an HIV+ patient accidentally cut himself with a scalpel. He comes to you, suspecting himself to have contracted the virus. Which test will you advise him to rule out/confirm his suspicion?

  1. PCR
  2. Routine urine examination
  3. TLC
  4. DLC

Answer. 1. PCR

Question 51. Match the following genes in column 1 with the insects that can be protected from with their coded proteins in column 2.

Column 1                    Column 2

a. cry I Ac                   (1) Cotton bollworm

b.cry I Ab                  (2) Beetles

c. Bt toxin gene        (3) Corn borer

  1. a (1), b (3), c (2)
  2. a (2), b (1), c (3)
  3. a (1), b (2), c (3)
  4. a (2), b (3), c (1)

Answer. 1. a (1), b (3), c (2)

Question 52. Which protein would you like to be produced by genetic engineering as cure for diseases such as emphysema?

  1. α-1-Antitrypsin
  2. Trypsin
  3. Chymotrypsin
  4. All of the above are required

Answer. 1. α-1-Antitrypsin

Question 53. “Rosie,” a transgenic cow, is known to produce a type of milk which has all the following characteristics, except

  1. Protein content of 2.4 g/L
  2. Has human a-lactalbumin
  3. More balanced diet than normal cow milk for babies
  4. Was produced for the first time in 2001

Answer. 4. Was produced for the first time in 2001

Question 54. According to the latest estimates, how many documented varieties of basmati rice are grown in India?

  1. 30
  2. 27
  3. 118
  4. 125

Answer. 2. 27

Question 55. Which ingredient was present in high concentrations in genetically modified (GM) rice as compared to the usual rice?

  1. Protein
  2. Carbohydrates
  3. Na+ ions
  4. Vitamin A

Answer. 4. Vitamin A

Question 56. Which of the following cannot be achieved using PCR?

  1. Detect HIV in AIDS suspect.
  2. Detect mutations in cancer patients.
  3. Detect antigen-antibody interactions
  4. Detect specific microorganisms from soil.

Answer. 3. Detect antigen-antibody interactions

Question 57. In electrophoresis, the separation of DNA fragments is based on

  1. Charge
  2. Mass only
  3. Size
  4. Both (1) and (3)

Answer. 4. Both (1) and (3)

Question 58. Pick the odd one out:

  1. DNA microinjection
  2. RNA interference
  3. Retro virus mediated gene transfer
  4. Embryonic stem cell mediated gene transfer

Answer. 2. RNA interference

Question 59. In xenotransplantation, a protein that causes graft rejection usually comes from transgenic

  1. Cow
  2. Mice
  3. Pig
  4. Sheep

Answer. 3. Pig

Question 60. Transgenics has provided many pharmaceuticals in their milk for the treatment of diseases. Which one of the following has not been a successful story?

  1. Phenylketonuria
  2. SCID
  3. Emphysema (hereditary)
  4. CFTR

Answer. 2. SCID

Question 61. Which is not true with respect to transgenic animals and their contribution to human welfare?

  1. Transgenic mice are being tested to ensure safety of polio vaccine.
  2. Rosie’s milk contained human gene insulin.
  3. Transgenic cows produce milk with less lactose.
  4. Transgenic sheep grow more wool.

Answer. 2. Rosie’s milk contained human gene insulin.

Question 62. An antibacterial compound that prevents mastitis in cows is

  1. α-1-Antitrypsin
  2. Lysostaphin
  3. Lysozyme
  4. Alginate lyase

Answer. 2. Lysostaphin

Question 63. Choose the incorrect statement with respect to bioweapons:

  1. They are low-cost weapons.
  2. They cause more casualties than conventional weapons.
  3. They are extremely difficult to detect.
  4. Bacterium E. coli created letter scare in 2001.

Answer. 4. Bacterium E. coli created letter scare in 2001.

Question 64. A set of standards by which a community regulates its behavior and activities in relation to the biological world is termed as

  1. Biopatent
  2. Biopiracy
  3. Patent
  4. Bioethic

Answer. 4. Bioethic

Question 65. Nexia Biotechnologies spliced spider genes into the cells of lactating

  1. Cow
  2. Sheep
  3. Goat
  4. None of these

Answer. 3. Goat

Question 66. Nif gene for nitrogen fixation in cereal crops such as wheat and jowar is introduced by cloning

  1. Rhizobium meliloti
  2. Bacillus thuringiensis
  3. Rhizopus
  4. Rhizophora

Answer. 1. Rhizobium meliloti

Question 67. VNTRS represent

  1. New terminal regions in DNA
  2. Functional genes in DNA
  3. Split genes in sample DNA
  4. Specific non-coding sequences with unique tandem repeats

Answer. 4. Specific non-coding sequences with unique tandem repeats

Question 68. Sheep Dolly was genetically similar to

  1. The mother from which nucleated fertilized egg was taken
  2. The mother from which the nucleus of udder cell was taken
  3. The surrogate mother
  4. Both surrogate mother and nuclear donor mother

Answer. 2. The mother from which the nucleus of udder cell was taken

” biotechnology applications”

Question 69. How does a bacterial cell protect its own DNA from restriction enzymes?

  1. By adding methyl groups to adenines and cystosines.
  2. By reinforcing bacterial DNA structure with covalent phosphodiester bonds.
  3. By adding histones to protect the double-stranded DNA
  4. By forming “sticky ends” of bacterial DNA to prevent the enzyme from attaching.

Answer. 1. By adding methyl groups to adenines and cystosines.

Question 70. All cells contain the same genetic information. Why cannot cells other than stem cells differentiate into various tissues?

  1. As cells develop, their genetic makeup changes.
  2. Stem cells are the only cells that can be implanted.
  3. Stem cells are the only cells that do not have an X or Y chromosome and can, therefore, go into either a male or a female.
  4. As cells develop, some genes are turned off permanently.

Answer. 4. As cells develop, some genes are turned off permanently.

Question 71. Polymerase chain reaction technology (PCR-technique) is used for

  1. DNA identification
  2. DNA repair
  3. DNA amplification
  4. Cleave DNA

Answer. 3. DNA amplification

Question 72. Which scientists obtained interferon through recombinant DNA technology?

  1. Kohler and Milstein
  2. Charles Weisman
  3. Nathans and Smith
  4. An American firm

Answer. 2. Charles Weisman

Question 73. When the genotype of an organism is improved by the addition of a foreign gene, the process is called

  1. Tissue culture
  2. Genetic diversity
  3. Genetic engineering
  4. Plastic surgery

Answer. 3. Genetic engineering

Question 74. A genetically manipulated organism containing in its genome one or more inserted genes of another species is called

  1. Transposon
  2. Gene expression
  3. Transgenic organism
  4. Retroposons

Answer. 3. Transgenic organism

Question 75. The use of transgenic plants as biological factories for the production of special chemicals is called

  1. Molecular farming
  2. Molecular genetics
  3. Molecular mapping
  4. Dry farming

Answer. 1. Molecular farming

Question 76. Which vector is commonly used in the transfer of gene in a crop plant?

  1. Plasmids of B. subtilis
  2. Bacteriophages
  3. Ti plasmids of Agrobacterium
  4. E. coli phages

Answer. 3. Ti plasmids of Agrobacterium

Question 77. The tumor inducing capacity of Agrobacterium tumaefaciens is located in large extrachromosomal plasmid called

  1. Ti plasmid
  2. Ri plasmid
  3. Lambda phage
  4. Plasmid pBR322

Answer. 1. Ti plasmid

Question 78. Genetic engineering aims at

  1. Destroying wild gene
  2. Preserving defective gene
  3. Curing human disease by introducing new gene (hemophilia)
  4. All the above

Answer. 3. Curing human disease by introducing new gene (hemophilia)

Question 79. Taq polymerase which is used in amplification of DNA is related with

  1. Hybridoma technique
  2. PCR technique
  3. Gene cloning
  4. rDNA technology

Answer. 2. PCR technique

Question 80. DNA fragments separated by gel electrophoresis are shown. Mark the correct statement:

NEET Biology Bio Technology And Its Applications Question 80

  1. Band 3 contains more positively charged DNA molecules than band 1.
  2. Band 3 indicates more charge density than bands 1 and 2.
  3. Band 1 has longer DNA fragment than bands 2 and 3.
  4. All bands have equal length and charges but differ in base composition.

Answer. 3. Band 1 has longer DNA fragment than bands 2 and 3.

Question 81. Thermal cycle takes place in which technique?

  1. Gel electrophoresis
  2. PCR technique
  3. Centrifugation
  4. Southern blotting

Answer. 2. PCR technique

Question 82. Cry gene, which synthesizes crystal protein, is isolated from

  1. Bacillus thuringiensis
  2. Rhizobium
  3. Bacillus polymyxa
  4. Clostridium

Answer. 1. Bacillus thuringiensis

Question 83. Which of the following risks is associated with genetically modified food?

  1. Toxicity
  2. Allergic reaction
  3. Antibiotic resistance in microorganisms present in alimentary canal
  4. All of the above

Answer. 4. All of the above

Question 84. PCR technique is used in

  1. Production of transgenic microbes
  2. Production of genetically modified food
  3. Forensic investigation
  4. rDNA technique

Answer. 3. Forensic investigation

Question 85. TDF gene is a

  1. Gene present on X-chromosome
  2. Segment of RNA
  3. Proteinaceous factor
  4. Gene present on Y-chromosome

Answer. 4. Gene present on Y-chromosome

Question 86. BACS and YACs are

  1. Natural DNA obtained from bacteria and yeast
  2. Useful vectors for eukaryotic gene transfer
  3. Artificial DNA obtained from bacteria and yeast
  4. (2) and (3) both

Answer. 4. (2) and (3) both

Question 87. Gene therapy was first used in the treatment of

  1. Albinism
  2. Hemophilia
  3. SCID
  4. LIQID

Answer. 3. SCID

Question 88. DNA probe is used for

  1. DNA fingerprinting
  2. Detection of pathogenic bacteria
  3. Medical genetics to find whether a person carries a particular gene or not
  4. All of the above

Answer. 4. All of the above

Question 89. Bt cotton is resistant to

  1. Roundworm
  2. Flukeworm
  3. Bollworm
  4. Pinworm

Answer. 3. Bollworm

Question 90. A genetically engineered microorganism used successfully in the bioremediation of oil spills is a species of

  1. Pseudomonas
  2. Trichoderma
  3. Xanthomonas
  4. Bacillus

Answer. 1. Pseudomonas

Question 91. The first transgenic plant is

  1. Potato
  2. Tomato
  3. Tobacco
  4. Maize

Answer. 3. Tobacco

Question 92. Sheep Dolly was obtained by

  1. Cloning the udder cell (somatic cell) fused with uninucleated oocyte
  2. Cloning of gametes
  3. Tissue culture
  4. None

Answer. 1. Cloning the udder cell (somatic cell) fused with uninucleated oocyte

Question 93. E. coli are used in the production of

  1. Rifampicin
  2. LH
  3. Ecdyson
  4. Interferon

Answer. 4. Interferon

Question 94. A gaint rat is formed in the laboratory. What is the reason?

  1. Gene mutation
  2. Gene synthesis
  3. Gene manipulation
  4. Gene replication

Answer. 3. Gene manipulation

Question 95. The first cloned animal was

  1. Dolly sheep
  2. Polly sheep
  3. Molly sheep
  4. Dog

Answer. 1. Dolly sheep

Question 96. Introduction of food plants developed by genetic engineering is not desirable because

  1. Economy of developing countries may suffer
  2. These products are less tasty as compared to the already existing products
  3. This method is costly
  4. There is danger of introduction of viruses and toxins with introduced crop

Answer. 4. There is danger of introduction of viruses and toxins with introduced crop

Question 97. Which one of the following has found extensive use in genetic engineering work in plants?

  1. Bacillus coagulans
  2. Agrobacterium tumefaciens
  3. Clostridium septicum
  4. Xanthomonas citri

Answer. 2. Agrobacterium tumefaciens

Question 98. The maximum application of animal cell culture technology today is in the production of

  1. Vaccines
  2. Edible protein
  3. Insulin
  4. Interferon

Answer. 1. Vaccines

Question 99. Ti plasmid is often used for making transgenic plants. This plasmid is found in

  1. Yeast as a 2-mm plasmid
  2. Azotobacter
  3. Rhizobium of the roots of leguminous plants
  4. Agrobacterium

Answer. 4. Agrobacterium

” biotechnology in industry”

Question 100. The cultivation of Bt cotton has been much in the news. Prefix “Bt” means

  1. “Barium-treated” cotton seeds
  2. “Bigger thread” variety of cotton with better tensile strength
  3. Produced by “biotechnology” using restriction enzymes and ligases
  4. Carrying an endotoxin gene from Bacillus thuringienisis

Answer. 4. Carrying an endotoxin gene from Bacillus thuringienisis

Question 101. An example of gene therapy is

  1. Production of injectable hepatitis B vaccine
  2. Production of vaccines in food crops such as potatoes which can be eaten
  3. Introduction of gene for adenosine deaminase in persons suffering from severe combined immunodeficiency (SCID)
  4. Production of test-tube babies by artificial insemination and implantation of fertilized eggs

Answer. 3. Introduction of gene for adenosine deaminase in persons suffering from severe combined immunodeficiency (SCID)

Question 102. Bacteria Pseudomonas is useful because of its ability to

  1. Transfer genes from one plant to another
  2. Decompose a variety of organic compounds
  3. Fix atmospheric nitrogen in the soil
  4. Produce a wide variety of antibiotics

Answer. 2. Decompose a variety of organic compounds

Question 103. Bacillus thuringiensis (Bt) strains have been used for designing novel

  1. Bioinsecticidal plants
  2. Bio-mineralization processes
  3. Biofertilizers
  4. Bio-metallurgical techniques

Answer. 1. Bioinsecticidal plants

Question 104. Which one of the following is a correct statement?

  1. “Bt” in Bt-cotton indicates that it is a genetically modified organism produced through biotechnology.
  2. Somatic hybridization involves the fusion of two complete plant cells carrying desired genes.
  3. The anticoagulant hirudin is being produced from transgenic Brassica napus seeds.
  4. “Flavr Savr” variety of tomato has enhanced the production of ethylene which improves its taste.

Answer. 3. The anticoagulant hirudin is being produced from transgenic Brassica napus seeds.

Question 105. The approximate number of genes contained in the genome of Kalpana Chowla was

  1. 40,000
  2. 30,000
  3. 80,000
  4. 1,00,000

Answer. 2. 30,000

Question 106. In transgenics, the expression of transgene in target tissue is determined by

  1. Reporter
  2. Enhancer
  3. Transgene
  4. Promoter

Answer. 4. Promoter

Question 107. Golden rice is a promising transgenic crop. When released for cultivation, it will help in

  1. Alleviation of vitamin A deficiency
  2. Pest resistance
  3. Herbicide tolerance
  4. Producing a petrol-like fuel from rice

Answer. 1. Alleviation of vitamin A deficiency

Question 108. Agrobacterium tumefaciens contains a large plasmid, which induces tumor in plants. It is termed as

  1. Ti plasmid
  2. Ri plasmid
  3. Recombinant plasmid
  4. Shine-Dalgarno sequence

Answer. 1. Ti plasmid

Question 109. Transgenic crops are modified through genetic engineering to develop natural resistance to insect pests. Which one is a transgenic plant?

  1. Tobacco and cotton
  2. Tomato and rice
  3. Maize and sugarcane
  4. Tomato and wheat

Answer. 1. Tobacco and cotton

Question 110. Genetically engineered human insulin is called

  1. Humulin
  2. Haematin
  3. Hybriodoma
  4. Hybrid

Answer. 1. Humulin

Question 111. Abzymes are

  1. Abnormal enzymes
  2. Enzymes acting on antibodies
  3. Antibodies acting as enzymes
  4. All of these

Answer. 3. Antibodies acting as enzymes

Question 112. Hybridoma technology was developed by

  1. Taggart, 1982
  2. Prie and Saxton, 1987
  3. Vitella et. al., 1982
  4. Kohler and Milstein

Answer. 4. Kohler and Milstein

Question 113. The technique for monoclonal antibody production was discovered by

  1. Steward and Skoog
  2. Arban and Haberlan
  3. Kohler and Milstein
  4. Lister and Koach

Answer. 3. Kohler and Milstein

Question 114. The first clinical gene therapy was given for treating

  1. Both sense and anti-sense RNA
  2. A particular hormone
  3. An antifeedant
  4. A toxic protein

Answer. 1. Both sense and anti-sense RNA

Question 115. Tobacco plants resistant to nematode have been developed by the introduction of DNA that produced (in the host cells)

  1. Diabetes mellitus
  2. Chicken pox
  3. Rheumatoid arthritis
  4. Adenosine deaminase deficiency

Answer. 4. Adenosine deaminase deficiency

Question 116. Which of the following Bt crops is being grown in India by the farmers?

  1. Cotton
  2. Brinjal
  3. Soybean
  4. Maize

Answer. 1. Cotton

Assertion-Reasoning Questions

In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R).

  1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark (1).
  2. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
  3. If Assertion is true but Reason is false, then mark (3).
  4. If both Assertion and Reason are false, then mark (4).

Question 91. Assertion: RNAi takes place in all eukaryotic organisms as a method of cellular defense.

Reason: Complementary dsRNA molecule binds to specific mRNA and prevents its translation (silencing).

Answer. 2. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark (2).

Question 92. Assertion: Bt toxin is a protein crystal containing insecticidal protein.

Reason: B. thuringiensis forms these protein crystals continuously throughout its growth period.

Answer. 3. If Assertion is true but Reason is false, then mark (3).

Question 93. Assertion: Recombinant DNA technology has been less effective in therapeutic drug production.

Reason: Recombinant therapeutics induces unwanted immunological responses.

Answer. 4. If both Assertion and Reason are false, then mark (4).

Question 94. Assertion: Transgenic mice are being used to test the safety of the polio vaccine.

Reason: It could replace the use of monkeys to test the safety of batches of the vaccine.

Answer. 2. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark (2).

Question 95. Assertion: Indian Government has set up organizations such as GEAC (Genetic Engineering Approval Committee), which will make decisions regarding the validity of GM research and the safety of introducing GM organisms for public services.

Reason: Genetic modification of organisms can have unpredictable results when such organisms are introduced into the ecosystem.

Answer. 1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark (1).

NEET Biology Multiple Choice Questions – Biotechnology: Principles and Processes

by

NEET Biology – Biotechnology: Principles and Processes

Question 1. 3′-5′ exonucleolytic degradation of DNA is performed by which enzyme?

  1. DNA polymerase
  2. Alkaline phosphatase
  3. DNA ligase
  4. RNA polymerase

Answer. 1. DNA polymerase

Question 2. The technique of gel electrophoresis was developed by

  1. Kary Mullis
  2. J.S. Chamberlain
  3. A. Tiselius
  4. F. Sanger

Answer. 3. A. Tiselius

Question 3. Which of the following dyes can be used to visualize nucleic acid after electrophoresis?

  1. Acridine orange
  2. Ethidium bromide
  3. Bromophenol blue
  4. Both (1) and (2)

Answer. 4. Both (1) and (2)

Question 4. Which of the following bonds are formed by the action of DNA ligase?

  1. Sugar-phosphate bond
  2. Phosphodiester bond
  3. Both (1) and (2)
  4. Phosphate-phosphate bond

Answer. 3. Both (1) and (2)

Question 5. Who were responsible for the isolation of “methylase” kind of enzyme from E. coli in 1960’s?

  1. Cohen and Boyer
  2. Banting and Best
  3. Linn and Arber
  4. Smith and Wilcox

Answer. 3. Linn and Arber

Question 6. The specific sequence recognized by “molecular scissors” is called

  1. Isomer
  2. Isobar
  3. Misnomer
  4. Palindrome

Answer. 4. Palindrome

Question 7. When a piece of DNA is digested with Eco RI, what kind of ends are created?

  1. Blunt ends
  2. Flush ends
  3. Cohesive ends
  4. Non-staggered ends

Answer. 3. Cohesive ends

” biotechnology principles and processes “

Question 8. The sticky ends generated by the action of Eco RI on insert DNA facilitate the action of which enzyme?

  1. DNA polymerase
  2. Taq polymerase
  3. Alkaline phosphatase
  4. DNA ligase

Answer. 4. DNA ligase

Question 9. Which is incorrect with respect to DNA polymerase III?

  1. It requires ATP for polymerase action.
  2. It is required for PCR.
  3. It is more active than DNA polymerases I and II.
  4. It requires a pre-formed DNA template to work on.

Answer. 2. It is required for PCR.

Question 10. Which is not an application of modern biotechnology?

  1. Production of humulin
  2. Developing a DNA vaccine
  3. Gene therapy
  4. Production of cheese and butter

Answer. 4. Production of cheese and butter

Question 11. Which of the following cannot be related to biotechnology?

  1. Integration of natural science and organisms.
  2. Techniques to alter the chemistry of DNA.
  3. Introducing undesirable genes into the target organism.
  4. Maintenance of sterile ambience to enable the growth of only the desired microbes.

Answer. 3. Introducing undesirable genes into the target organism.

Question 12. Which of the following specific DNA sequence is responsible for initiating replication?

  1. Vector site
  2. Restriction enzymes action site
  3. Ori site
  4. Palindromic site

Answer. 3. Ori site

Question 13. Autonomously replicating, circular, extra chromosomal DNA of prokaryotic cell is called

  1. Satellite DNA
  2. Plasmid
  3. Recombinant DNA
  4. Nucleoid

Answer. 2. Plasmid

Question 14. Key tools to be involved in recombinant DNA technology are

A. Restriction enzymes

B. Polymerase enzyme

C. Ligase enzymes

D. Vectors

  1. (A) only
  2. (A) and (C) only
  3. (A), (B), and (C)
  4. (A), (B), (C), and (D)

Answer. 4. (A), (B), (C), and (D)

Question 15. The first restriction endonuclease to be discovered was

  1. Hind II
  2. Eco RI
  3. Bam HI
  4. Pst I

Answer. 1. Hind II

” short notes on biotechnology”

Question 16. Approximately, how many restriction enzymes have been isolated from the different (over 230) strains of bacteria?

  1. 300
  2. 600
  3. 750
  4. 900

Answer. 4. 900

Question 17. The conventional method for naming restriction enzymes is followed. In case of Eco RI, the “R” indicates

  1. Genus
  2. Species
  3. Name of the scientist
  4. Strain

Answer. 4. Strain

Question 18. The restriction endonuclease enzyme binds to the DNA and cuts

  1. Any one strand of the double helix
  2. Each of the two strands at specific points in their base-sugar bonds
  3. Each of the two strands at specific points in their base-phosphate bonds
  4. Each of the two strands at specific points in their sugar-phosphate backbones

Answer. 4. Each of the two strands at specific points in their sugar-phosphate backbones

Question 19. During gel electrophoresis, for the separation of DNA fragment, the

  1. Smallest fragment will move to the farthest point towards cathode
  2. Smallest fragment will move to the farthest point towards anode
  3. Largest fragment will move to the farthest point towards cathode
  4. Largest fragment will move to the farthest point towards anode

Answer. 2. Smallest fragment will move to the farthest point towards anode

Question 20. After electrophoresis, the separated DNA fragment can be visualized in ethidium bromide gel exposed to UV light. These DNA fragments appear as _________ colored bands.

  1. Orange
  2. Blue
  3. Silver
  4. Green

Answer. 1. Orange

Question 21. The procedure through which a piece of DNA is introduced in a host bacterium is called

  1. Cloning
  2. Transformation
  3. PCR
  4. Clonal selection

Answer. 2. Transformation

Question 22. After completing the transformation experiment involving the coding sequence of enzyme a-galactosidase, the recombinant colonies should

  1. Give blue color
  2. Not give blue color
  3. Have active α-galactosidase
  4. Both (2) and (3)

Answer. 2. Not give blue color

Question 23. Which of the following has the ability to transform normal cells into cancerous cells in animals?

  1. Agrobacterium tumifaciens
  2. Retroviruses
  3. DNA viruses
  4. Plasmids

Answer. 2. Retroviruses

Question 24. Which of the following is not applicable to Agrobacterium tumifaciens?

  1. Pathogen of several dicot plants.
  2. Has the ability to transform normal plant cells.
  3. Delivers gene of our interest.
  4. Ti plasmid of it is always pathogenic to plants with out any exception.

Answer. 4. Ti plasmid of it is always pathogenic to plants with out any exception.

Question 25. Insertional inactivation is related to

  1. Microinjection
  2. Gene gun
  3. Gel electrophoresis
  4. Selection of recombinants

Answer. 4. Selection of recombinants

Question 26. For transformation with recombinant DNA, the bacterial cells must first be made competent, which means

  1. Should increase their metabolic reactions
  2. Should decrease their metabolic reactions
  3. Increase efficiency with which DNA enters the bacterium
  4. Ability to divide fast

Answer. 3. Increase efficiency with which DNA enters the bacterium

Question 27. Which of the following method can be used for making the bacterial cell competent?

  1. Treating with specific concentration of divalent cation (Ca2+).
  2. Treating with specific concentration of monovalent cation (K).
  3. Heat shock.
  4. Both (1) and (3).

Answer. 4. Both (1) and (3).

“biotechnology notes “

Question 28. Which of the following techniques can be used to introduce foreign DNA into cell?

  1. Using disarmed pathogen
  2. Microinjection
  3. Gene gun
  4. All of these

Answer. 4. All of these

Question 29. During heat shock, the temperature used for giving thermal shock to the bacterium is

  1. 82°C
  2. 100°C
  3. Liquid nitrogen
  4. 42°C

Answer. 4. 42°C

Question 30. Which of the following enzymes is used in case of fungus to cause the release of DNA along with other macromolecules?

  1. Lysozyme
  2. Cellulase
  3. Chitinase
  4. Amylase

Answer. 3. Chitinase

Question 31. During the isolation of DNA, the addition of which of the following causes the precipitation of purified DNA?

  1. Chilled ethanol
  2. Ribonuclease enzyme
  3. DNA polymerase
  4. Proteases

Answer. 1. Chilled ethanol

Question 32. Which of the following is the correct sequence of PCR (polymerase chain reaction)?

  1. Denaturation → Annealing → Extension
  2. Extension → Denaturation → Annealing
  3. Annealing → Extension → Denaturation
  4. Denaturation → Extension → Annealing

Answer. 1. Denaturation → Annealing → Extension

Question 33. The most commonly used bioreactor is of stirring type. The stirrer facilitates

  1. Temperature control
  2. pH control
  3. Oxygen availability
  4. Product removal

Answer. 3. Oxygen availability

Question 34. After the completion of biosynthetic stage, the separation and purification of product is called

  1. Upstream processing
  2. Downstream processing
  3. Modern biotechnology
  4. Gene amplification

Answer. 2. Downstream processing

Question 35. From isolated DNA from a cell culture with seven de- sired genes, DNA segment can be excised by molecular scissors or chemical scalpels what biotechnologists call as

  1. Polymerase enzymes
  2. DNA ligase
  3. Restriction enzymes
  4. Helicase

Answer. 3. Restriction enzymes

Question 36. All the following statements about Stanley Cohen and Herbert Boyer are correct but one is wrong. Which one is wrong?

  1. They discovered recombinant DNA (rDNA) technology, and this marks the birth of modern biotechnology.
  2. They first produced healthy sheep clone, a Finn Dorset lamb, Dolly, from the differentiated adult mammary cells.
  3. They invented genetic engineering by combining a piece of foreign DNA containing a gene from a bacterium with a bacterial plasmid using the enzyme restriction endonuclease.
  4. They isolated the antibiotic resistance gene by cutting out a piece of DNA from the plasmid which was responsible for conferring antibiotic resistance.

Answer. 2. They first produced healthy sheep clone, a Finn Dorset lamb, Dolly, from the differentiated adult mammary cells.

Question 37. What is the fate of a piece of DNA which is somehow transferred into an alien organism?

  1. This piece of DNA would not be able to multiply itself in the progeny cells of the organism if not integrated into the genome of the organism.
  2. If the alien piece of DNA has become a part of the chromosome, it will replicate.
  3. If the alien piece of DNA is linked with the origin of replication in chromosome, it will replicate.
  4. All of these.

Answer. 4. All of these.

Question 38. In the year 1963, the two enzymes responsible for restricting the growth of bacteriophage in Escherichia coli were isolated. These were and, respectively.

  1. Ligase, restriction endonuclease
  2. Helicase, restriction endonuclease
  3. Methylase, restriction endonuclease
  4. DNA polymerase, restriction endonuclease

Answer. 3. Methylase, restriction endonuclease

“process of biotechnology “

Question 39. The cutting of DNA by restriction endonucleases results in fragments of DNA. These fragments are generally separated by a technique known as

  1. Gel-filtration chromatography
  2. Centrifugation
  3. Gel electrophoresis
  4. Thin-layer chromatography

Answer. 3. Gel electrophoresis

Question 40. Which of the following bacteria are known as natural genetic engineers of plants, as gene transfer is happening in nature without human interference?

  1. Azotobacter
  2. Agrobacterium tumefaciens
  3. Escherichia coli
  4. Rhizobium

Answer. 2. Agrobacterium tumefaciens

Question 41. The technique in which a foreign DNA is precipitated on the surface of tungsten or gold particles and shot into the target cells is known as

  1. Microinjection
  2. Chemical-mediated genetic transformation
  3. Electroporation
  4. Biolistics

Answer. 4. Biolistics

Question 42. The isolation of the genetic material in pure form-free from other macromolecules can be achieved by treating the bacterial cells/plant or animal tissues with the following enzymes, except

  1. Lysozyme
  2. Cellulase
  3. Chitinase
  4. Ligase

Answer. 4. Ligase

Question 43. Which of the following is not a recombinant protein used in medical practice?

  1. TPA (tissue plasminogen activator)
  2. Interferon (α, B, and 7)
  3. Vaccine (for hepatitis B)
  4. Heparin

Answer. 4. Heparin

Question 44. cDNA is

  1. Circular DNA in bacteria
  2. Complementary DNA
  3. Copy DNA
  4. Both (2) and (3)

Answer. 4. Both (2) and (3)

Question 45. The Noble Prize of 1978 for restriction endonuclease technology was given to

  1. Temin and Baltimore
  2. Milstein and Kohler
  3. Arber, Nathans, and Smith
  4. Holley, Khorana, and Nirenberg

Answer. 3. Arber, Nathans, and Smith

Question 46. Plasmids are used in genetic engineering because they

  1. Are easily available
  2. Are able to integrate with host chromosome
  3. Are able to replicate along with chromosomal DNA
  4. Contain DNA sequence coding for drug resistance

Answer. 3. Are able to replicate along with chromosomal DNA

Question 47. Which of the following processes and techniques are included under biotechnology?

A. In vitro fertilization leading to a test-tube baby.

B. Synthesizing gene and using it.

C. Developing DNA vaccine.

D. Correcting a defective gene.

  1. (B) and (D) only (3)
  2. (B), (C), and (D)
  3. (A) and (B)
  4. (A), (B), (C), and (D)

Answer. 4. (A), (B), (C), and (D)

Question 48. The tumor-inducing (Ti) plasmid has now been modified to a cloning vector which is no more pathogenic to plants but is still able to use mechanisms to deliver genes of our interest into a variety of plants because Ti plasmid has been modified by

  1. Adding tumor-forming genes
  2. Deleting tumor-forming genes
  3. Adding genes resistant to endonucleases
  4. Deleting endonuclease

Answer. 2. Deleting tumor-forming genes

“biotechnology principles and processes class 12 “

Question 49. Which of the following statements is incorrect?

  1. Plasmids have the ability to replicate within the bacterial cells independent of the control of chromosomal DNA.
  2. Some plasmids have only one or two copies per cell whereas others may have 15-100 copies per cell.
  3. Bacteriophages have the ability to replicate within the bacterial cell independent of the control of chromosomal DNA.
  4. Transformation is a procedure of separation and isolation of DNA fragments.

Answer. 4. Transformation is a procedure of separation and isolation of DNA fragments.

Question 50. Which of the following is the first artificial cloning vector that has two selectable markers-tetracycline (tetR) and antibiotic restriction enzymes (ampR)?

  1. YAC
  2. BAC
  3. pBR322
  4. Cosmid vectors

Answer. 3. pBR322

Question 51. Restriction endonucleases are most widely used in recombinant DNA technology. They are obtained from

  1. Bacteriophage
  2. Bacterial cells
  3. Plasmids
  4. All prokaryotic cells

Answer. 2. Bacterial cells

Question 52. All the following statements are correct about genetic engineering, but one is wrong. Which one is wrong?

  1. It is a technique for artificially and deliberately modifying DNA (genes) to suit human needs.
  2. It is often referred as gene splicing.
  3. The organism carrying the foreign genes is termed as transgenic or GMO.
  4. Alec Jeffrey is the father of genetic engineering.

Answer. 4. Alec Jeffrey is the father of genetic engineering.

Question 53. All the following are the properties of enzyme Taq polymerase, except

  1. It is thermostable DNA polymerase
  2. It is isolated from a bacterium, Thermus aquaticus
  3. It is used for the amplification of gene of interest using PCR
  4. It is thermostable RNA polymerase

Answer. 4. It is thermostable RNA polymerase

Question 54. Which of the following is incorrect match?

  1. Gene therapy: An abnormal gene is replaced by normal gene
  2. Cloning: Ability to multiply copies of antibiotic resistance gene in E. coli
  3. Restriction enzymes: Molecular scissors
  4. Exonucleases: Molecular glue

Answer. 4. Exonucleases: Molecular glue

Question 55. Appropriate techniques have been developed for large- scale cell culture using bioreactors for producing

  1. Foreign gene product
  2. Vaccines
  3. Hormones
  4. All of these

Answer. 4. All of these

Question 56. The uptake of genes by cells in microbes and plants is termed as

  1. Insertional inactivation
  2. Transformation
  3. Selectable markers
  4. Cloning vectors

Answer. 2. Transformation

Question 57. If we ligate a foreign DNA at the BamHI site of tetracycline resistance gene in pBR322, the recombinant plasmid will

  1. Show ampicillin resistance only
  2. Show tetracycline resistance
  3. Will grow well on tetracycline-containing medium
  4. Will not grow on ampicillin-containing medium

Answer. 1. Show ampicillin resistance only

Question 58. Polyethylene glycol can help in the uptake of foreign DNA into the host cell. This type of gene transfer is called

  1. Electroporation
  2. Chemical mediated genetic transformation
  3. Microinjection
  4. Particle gun

Answer. 2. Chemical mediated genetic transformation

Question 59. The normal E. coli cells carry resistance against which of the following antibiotics?

  1. Ampicillin
  2. Chloramphenicol
  3. Tetracycline or kanamycin
  4. None of these

Answer. 4. None of these

Question 60. The isolation of genetic material from fungal cells does not involve the use of

  1. Agarose
  2. Chitinase
  3. Ethanol
  4. Water

Answer. 1. Agarose

“biotechnology process “

Question 61. In a restriction digestion experiment, the sticky ends of vector rejoined forming a circular vector without insert. Which enzyme can be used to eliminate this possibility?

  1. DNA ligase
  2. Alkaline phosphatase
  3. DNA polymerase
  4. RNA polymerase

Answer. 2. Alkaline phosphatase

Question 62. Denaturation can be achieved at which temperature during PCR?

  1. 72°C
  2. 95°C
  3. 40°C
  4. 25°C

Answer. 2. 95°C

Question 63. Choose the incorrect statement with respect to Agrobacterium tumefaciens.

  1. It is a Gram-negative soil bacterium.
  2. It produces crown gall disease in dicot plants.
  3. The foreign DNA is inserted at the ori site of Ti plasmid.
  4. Ti plasmid becomes incorporated into the plant chromosomal DNA.

Answer. 3. The foreign DNA is inserted at the ori site of Ti plasmid.

Question 64. Which is not a method for the introduction of recombinant DNA into host cells?

  1. Electroporation
  2. Biolistics
  3. Transfection
  4. Restriction digestion

Answer. 4. Restriction digestion

Question 65. The essential requirements for a gene amplification reaction are

  1. 20 mg of DNA template
  2. Forward and reverse primers
  3. Mg2+
  4. All of these

Answer. 4. All of these

Question 66. Choose the incorrect statement with respect to PCR reaction:

  1. It requires Taq polymerase.
  2. It requires dNTP’s.
  3. It generates 2n molecules after n number of cycles.
  4. The optimum temperature for polymerization step is greater than or equal to 90°C.

Answer. 4. The optimum temperature for polymerization step is greater than or equal to 90°C.

Question 67. Which is not an application of PCR?

  1. DNA fingerprinting
  2. DNA foot-printing
  3. Detection of mutation
  4. Prenatal diagnosis

Answer. 2. DNA foot-printing

Question 68. Rejoining of vector molecule after restriction enzyme digestion can be avoided by

  1. Using different enzymes for insert and vector
  2. Using same enzyme for insert and vector
  3. Using DNA ligase immediately after digestion
  4. Using alkaline phosphatase on only vector

Answer. 4. Using alkaline phosphatase on only vector

biotechnology processes

Question 69. If the target gene is inserted at Sal 1 site of the recombinant, plasmid will show resistance for pBR322

  1. Ampicillin
  2. Tetracyline
  3. Both (1) and (2)
  4. Kanamycin

Answer. 1. Ampicillin

Question 70. It is theoretically possible for a gene from any organism to function in any other organism. Why is this possible?

  1. All organisms have ribosomes.
  2. All organisms have the same genetic code.
  3. All organisms are made up of cells.
  4. All organisms have similar nuclei.

Answer. 2. All organisms have the same genetic code.

Question 71. If you discovered a bacterial cell that contained no restriction enzymes, which of the following would you except to happen?

  1. The cell would create incomplete plasmids.
  2. The cell would be unable to replicate its DNA.
  3. The cell would become an obligate parasite.
  4. The cell would be easily infected by bacteriophages.

Answer. 4. The cell would be easily infected by bacteriophages.

Question 72. Assume that you are trying to insert a gene into a plasmid and someone gives you a preparation of DNA cut with restriction enzyme X. The gene you wish to insert has sites on both ends for cutting by restriction enzyme Y. You have a plasmid with a single site for Y, but not for X. Your strategy should be to

  1. Cut the plasmid with restriction enzyme X and insert the fragments cut with Y into the plasmid
  2. Cut the plasmid with restriction enzyme X and insert the gene into the plasmid
  3. Cut the plasmid twice with restriction enzyme Y and ligate the two fragments into the plasmid cut with the same enzyme
  4. Cut the plasmid twice with restriction enzyme Y and ligate the two fragments onto the ends of the human DNA fragments cut with restriction enzyme X

Answer. 3. Cut the plasmid twice with restriction enzyme Y and ligate the two fragments into the plasmid cut with the same enzyme

Question 73. 1. Transform bacteria with recombinant DNA molecule.

2. Cut the plasmid DNA using restriction enzymes.

3. Extract plasmid DNA from bacterial cells.

4. Hydrogen-bond the plasmid DNA to non-plasmid DNA fragments.

5. Use ligase to seal plasmid DNA to non-plasmid DNA.

From the given list, which of the following is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium?

  1. 4, 5, 1, 2, 3
  2. 3, 2, 4, 5, 1
  3. 3, 4, 5, 1, 2
  4. 2, 3, 5, 4, 1

Answer. 2. 3, 2, 4, 5, 1

Question 74. A eukaryotic gene has sticky ends produced by restriction endonuclease Eco RI. The gene is added to a mixture containing Eco RI and a bacterial plasmid that carries two genes, which make it resistant to ampicillin and tetracyline. The plasmid has one recognition site for Eco RI located in the tetracycline resistance gene. This mixture is incubated for several hours and then added to bacteria growing in nutrient broth. The bacteria are allowed to grow overnight and are streaked on a plate using a technique which produces isolated colonies that are clones of the original. Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient broth plus ampicillin and tetracycline, and nutrient broth containing no antibiotics.

The bacteria containing the engineered plasmid would grow in

  1. The ampicillin and tetracycline broth only
  2. The nutrient broth, the ampicillin broth, and the tetracycline broth
  3. The nutrient broth and the ampicillin broth only
  4. The nutrient broth only

Answer. 3. The nutrient broth and the ampicillin broth only

Question 75. Agrobacterium tumefaciens is used in genetic engineering for

  1. DNA mapping
  2. DNA modification
  3. Vector
  4. DNA fingerprinting

Answer. 3. Vector

Question 76. A genetically engineered bacteria used for clearing oil spills is

  1. Escherischia coli
  2. Bacillus subtilis
  3. Agrobacterium tumefaciens
  4. Pseudomonas putida

Answer. 4. Pseudomonas putida

Question 77. Who isolated the first restriction endonucleases?

  1. Temin and Baltimore
  2. Sanger
  3. Nathans and Smith
  4. Paul Berg

Answer. 3. Nathans and Smith

Question 78. Genetic engineering is

  1. Study of extra-nuclear gene
  2. Manipulation of genes by artificial method
  3. Manipulation of RNA
  4. Manipulation of enzymes

Answer. 2. Manipulation of genes by artificial method

Question 79. Which of the following enzymes cut the DNA molecule at specific nucleotide sequence?

  1. Restriction endonuclease
  2. DNA ligase
  3. RNA polymerase
  4. Exonuclease

Answer. 1. Restriction endonuclease

Question 80. DNA fingerprinting was invented by

  1. Karl Mullis
  2. Alec Jeffery
  3. Dr. Paul Berg
  4. Francis Collins

Answer. 2. Alec Jeffery

Question 81. Which structure is involved in genetic engineering?

  1. Plastid
  2. Plasmid
  3. Codon
  4. None

Answer. 2. Plasmid

Question 82. Which of the following is the example of chemical scissors?

  1. Eco RI
  2. HindIII
  3. Bam I
  4. All of the above

Answer. 4. All of the above

Question 83. Restriction endonucleases are used in genetic engineering because

  1. They can degrade harmful proteins
  2. They can join DNA fragments
  3. They can cut DNA at variable sites
  4. They can cut DNA at specific base sequences

Answer. 4. They can cut DNA at specific base sequences

Question 84. Chimeric DNA is

  1. DNA which contains uracil
  2. DNA synthesized from RNA
  3. Recombinant DNA
  4. DNA which contains single strand

Answer. 3. Recombinant DNA

Question 85. A piece of nucleic acid used to find out a gene by forming hybrid with it is called

  1. cDNA
  2. DNA probe
  3. Sticky end
  4. Blunt end

Answer. 2. DNA probe

Question 86. Which of the following is the example of direct gene transfer?

  1. Microinjection
  2. Electroporation
  3. Particle gun
  4. All the above

Answer. 4. All the above

Question 87. How many copies of DNA sample are produced in PCR technique after 6 cycles?

  1. 4
  2. 32
  3. 16
  4. 64

Answer. 3. 16

Question 88. The basic procedure involved in the synthesis of recombinant DNA molecule is depicted. The mistake in the cedure is procedure is

NEET Biology Bio-Technology Principles And Process Question 89

  1. Enzyme polymerase is not included
  2. The mammalian DNA is shown double stranded
  3. Only one fragment is inserted
  4. Two different restriction enzymes are used

Answer. 4. Two different restriction enzymes are used

Question 89. Western blotting is used for the identification of

  1. DNA
  2. RNA
  3. Protein
  4. All the above

Answer. 3. Protein

Question 90. In rDNA technique, which of the following technique is not used in introducing DNA into host cell?

  1. Transduction
  2. Conjugation
  3. Transformation
  4. Electroporation

Answer. 2. Conjugation

Question 91. Which of the following techniques are used in analyzing restriction fragment length polymorphism (RFLP)?

(a) Electrophoresis

(b) Electroporation

(c) Methylation

(d) Restriction digestion

  1. (a) and (c)
  2. (c) and (d)
  3. (a) and (d)
  4. (b) and (d)

Answer. 3. (a) and (d)

Question 92. Restriction enzymes are

  1. Not always required in genetic engineering
  2. Essential tool in genetic engineering
  3. Nucleases that cleave DNA at specific sites
  4. (2) and (3) both

Answer. 4. (2) and (3) both

Question 93. The function of restriction endonuclease enzyme is

  1. It is useful in genetic engineering
  2. It protects the bacterial DNA against foreign DNA
  3. It is helpful in transcription
  4. It is helpful in protein synthesis

Answer. 2. It protects the bacterial DNA against foreign DNA

Question 94. A bacterium modifies its DNA by adding methyl groups to the DNA. It does so to

  1. Clone its DNA
  2. Be able to transcribe many genes simultaneously
  3. Turn its gene on
  4. Protect its DNA from its own restriction enzyme

Answer. 4. Protect its DNA from its own restriction enzyme

Question 95. Plasmid has been used as vector because

  1. It is circular DNA which has capacity to join eukaryotic DNA
  2. It can move between prokaryotic and eukaryotic cells
  3. Both ends show replication
  4. It has antibiotic resistance gene

Answer. 1. It is circular DNA which has capacity to join eukaryotic DNA

Question 96. Which of the following cuts the DNA from specific places?

  1. Restriction endonuclease (Eco RI)
  2. Ligase
  3. Exonuclease
  4. Alkaline phosphate

Answer. 1. Restriction endonuclease (Eco RI)

Question 97. The manipulation of DNA in genetic engineering becomes possible due to the discovery of

  1. Restriction endonuclease
  2. DNA ligase
  3. Transcriptase
  4. Primase

Answer. 1. Restriction endonuclease

Question 98. Restriction enzymes

  1. Are endonucleases which cleave DNA at specific sites
  2. Make DNA complementary to an existing DNA or RNA
  3. Cut or join DNA fragments
  4. Are required in vector-less direct gene transfer

Answer. 1. Are endonucleases which cleave DNA at specific sites

Question 99. DNA fingerprinting refers to

  1. Techniques used for the identification of fingerprints of individuals
  2. Molecular analysis of profiles of DNA samples
  3. Analysis of DNA samples using imprinting devices
  4. Techniques used for molecular analysis of different specimens of DNA

Answer. 2. Molecular analysis of profiles of DNA samples

Question 100. Restriction endonucleases

  1. Are synthesized by bacteria as part of their defense compound
  2. Are present in mammalian cells for degradation of DNA when the cell dies
  3. Are used in genetic engineering for ligating two DNA molecules
  4. Are used for in vitro DNA synthesis

Answer. 1. Are synthesized by bacteria as part of their defense compound

Question 101. What is the first step in the Southern blot technique?

  1. Denaturation of DNA on the gel for hybridization with specific probe.
  2. Production of a group of genetically identical cells.
  3. Digestion of DNA by restriction enzyme.
  4. Isolation of DNA from a nucleated cell such as the one from the scene of crime.

Answer. 1. Denaturation of DNA on the gel for hybridization with specific probe.

Question 102. Which of the following is not produced by E. coli in lactose?

  1. B-galactosidase
  2. Thiogalactoside transacetylase
  3. Lactose dehydrogenase
  4. Lactose permease

Answer. 3. Lactose dehydrogenase

Question 103. The technique of transferring DNA fragment separated on agarose gel to a synthetic membrane such as nitrocellulose is known as

  1. Northern blotting
  2. Southern blotting
  3. Western blotting
  4. Dot blotting

Answer. 2. Southern blotting

Question 104. The production of a human protein in bacteria in genetic engineering is possible because

  1. Bacterial cell can carry out RNA splicing reactions
  2. The mechanism of gene regulation is identical in humans and bacteria
  3. Human chromosome can replicate in bacterial cell
  4. Genetic code is universal

Answer. 4. Genetic code is universal

Question 105. Electroporation procedure involves

  1. Fast passage of food through sieve pores in phloem elements with the help of electric stimulation
  2. Opening of stomatal pores during night by artificial light
  3. Making transient pores in the cell membrane to introduce gene constructs
  4. Purification of saline water with the help of a membrane system

Answer. 3. Making transient pores in the cell membrane to introduce gene constructs

Question 106. The total number of nitrogenous bases in human genome is estimated to be about

  1. 3.5 million
  2. 35 thousand
  3. 35 million
  4. 3.1 billion

Answer. 4. 3.1 billion

Question 107. Two microbes found to be very useful in genetic engineering are

  1. Escherichia coli and Agrobacterium tumefaciens
  2. Vibro cholerae and a tailed bacteriophage
  3. Diplococcus sp. and Pseudomonas sp.
  4. Crown gall bacterium and Caenorhabdits elegans

Answer. 1. Escherichia coli and Agrobacterium tumefaciens

Question 108. Restriction endonuclease

  1. Cuts the DNA molecule randomly
  2. Cuts the DNA molecule at specific sites
  3. Restricts the synthesis of DNA inside the nucleus
  4. Synthesizes DNA

Answer. 2. Cuts the DNA molecule at specific sites

Question 109. The restriction enzyme Eco RI has the property of

  1. Endonuclease activity
  2. Exonuclease activity
  3. Ligation activity
  4. Correcting the topology of replicating DNA

Answer. 1. Endonuclease activity

Question 110. DNA ligase is an enzyme that catalyzes the

  1. Splitting of DNA threads into small bits
  2. Joining of the fragments of DNA
  3. Denaturation of DNA
  4. Synthesis of DNA

Answer. 2. Joining of the fragments of DNA

Question 111. More advancement in genetic engineering is due to

  1. Restriction endonuclease
  2. Reverse transcriptase
  3. Protease
  4. Zymase

Answer. 1. Restriction endonuclease

Question 112. The function of PCR is

  1. Translation
  2. Transcription
  3. DNA amplification
  4. None of these

Answer. 3. DNA amplification

Question 113. Which of the following is used as the best genetic vector?

  1. Bacillus thuriengenesis
  2. Agrobacterium tumefaciens
  3. Pseudomonas putida
  4. All of these

Answer. 2. Agrobacterium tumefaciens

Question 114. The transfer of protein from electrophoretic gel to nitrocellulose membrane is known as

  1. Transferase
  2. Northern blotting
  3. Western blotting
  4. Southern blotting

Answer. 3. Western blotting

Question 115. DNA fingerprinting was first discovered by

  1. Alec Jeffery
  2. Cark Mullis
  3. C. Milstein
  4. Dr. Paul Berg

Answer. 1. Alec Jeffery

Question 116. Which of the following enzyme is used to join DNA fragments?

  1. Terminase
  2. Endonuclease
  3. Ligase
  4. DNA polymerase

Answer. 3. Ligase

Question 117. Restriction endonucleases are enzymes which

  1. Make cuts at specific positions within the DNA molecule
  2. Recognize a specific nucleotide sequence for binding of DNA ligase
  3. Restrict the action of enzyme DNA polymerase
  4. Remove nucleotides from the ends of the DNA molecule

Answer. 1. Make cuts at specific positions within the DNA molecule

Question 118. Satellite DNA is a useful tool in

  1. Organ transplantation
  2. Sex determination
  3. Forensic science
  4. Genetic engineering

Answer. 3. Forensic science

Question 119. PCR and restriction fragment length polymorphism are the methods for

  1. Genetic transformation
  2. DNA sequencing
  3. Genetic fingerprinting
  4. Study of enzymes

Answer. 3. Genetic fingerprinting

Question 120. Which one is a true statement regarding DNA polymerase used in PCR?

  1. It serves as a selectable marker.
  2. It is isolated from a virus.
  3. It remains active at high temperature.
  4. It is used to ligate introduced DNA in recipient cells.

Answer. 3. It remains active at high temperature.

Question 121. For transformation, microparticles coated with DNA to be bombarded with gene gun are made up of

  1. Platinum or zinc
  2. Silicon or platinum
  3. Gold or tungsten
  4. Silver or platinum

Answer. 3. Gold or tungsten

Question 122. A single strand of nucleic acid tagged with a radioactive molecule is called

  1. Selectable marker
  2. Plasmid
  3. Probe
  4. Vector

Answer. 3. Probe

Question 123. The following figure is the diagrammatic representation of the E. coli vector PBR 322. Which one of the given options correctly identifies its certain component(s)? 

  1. rop-reduced osmotic pressure
  2. Hind III, Eco RI-selectable markers
  3. ampR, tetR-antibiotic resistance genes
  4. ori-original restriction enzyme

Answer. 3. ampR, tetR-antibiotic resistance genes

NEET Biology Bio-Technology Principles And Process Question 29

Question 124. Which one of the following is a case of wrong matching?

  1. Vector DNA: Site for tRNA synthesis
  2. Micropropagation: In vitro production of plants in large numbers
  3. Callus: Unorganized mass of cells produced in tissue culture
  4. Somatic hybridization: Fusion of two diverse cells

Answer. 1. Vector DNA: Site for tRNA synthesis

Question 125. Biolistics (gene gun) is suitable for

  1. Disarming pathogen vectors
  2. Transformation of plant cells
  3. Constructing recombinant DNA by joining with vectors
  4. DNA fingerprinting

Answer. 3. Constructing recombinant DNA by joining with vectors

Question 126. In genetic engineering, the antibiotics are used

  1. As selectable markers
  2. To select healthy vectors
  3. As sequences from where replication starts
  4. To keep the cultures free of infection

Answer. 1. As selectable markers

Question 127. What is it that forms the basis of DNA fingerprinting?

  1. The relative proportions of purines and pyrimidines in DNA.
  2. The relative difference in the DNA occurrence in blood, skin, and saliva.
  3. The relative amount of DNA in the ridges and grooves of fingerprints.
  4. Satellite DNA occurring as highly repeated short DNA segments.

Answer. 4. Satellite DNA occurring as highly repeated short DNA segments.

Question 128. The following figure shows three steps (A)-(C) of PCR. Select the option giving correct identification together with what it represents?

NEET Biology Bio-Technology Principles And Process Question 34

Options:

  1. B-Denaturation at a temperature of about 98°C separating the two DNA strands
  2. A-Denaturation at a temperature of about 50°C
  3. C-Extension in the presence of heat stable DNA polymerase
  4. A-Annealing with two sets of primers

Answer. 3. C-Extension in the presence of heat stable DNA polymerase

Question 129. Which one of the following represents a palindromic sequence in DNA?

  1. 5′-GAATTC-3′; 3′- CTTAAG-5′
  2. 5′-CCATCC-3′; 3′-GAATCC-5′
  3. 5′-CATTAG-3′; 3′-GATAAC-5′
  4. 5′-GATACC-3′; 3′-CCTAAG-5′

Answer. 1. 5′-GAATTC-3′; 3′- CTTAAG-5′

Question 130. DNA fragments generated by restriction endonucleases in a chemical reaction can be separated by

  1. Polymerase chain reaction
  2. Electrophoresis
  3. Restriction mapping
  4. Centrifugation

Answer. 2. Electrophoresis

Question 131. The colonies of recombinant bacteria appear white in contrast to the blue colonies of non-recombinant bacteria because of

  1. Insertional inactivation of alpha-galactosidase in non-recombinant bacteria
  2. Insertional inactivation of alpha-galactosidase in recombinant bacteria
  3. Inactivation of glycosidase enzyme in recombinant bacteria
  4. Non-recombinant bacteria containing beta-galactosidase

Answer. 4. Non-recombinant bacteria containing beta-galactosidase

NEET Biology Notes – Biotechnology: Principles and Processes

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BioTechnology: Principles And Processes

Principles Of Biotechnology

  • Biotechnology can be broadly defined as “using living organisms or their products for commercial purposes.”
  • As such, biotechnology has been practiced by human society since the beginning of recorded history in activities such as baking bread, brewing alcoholic beverages, and breeding food crops or domestic animals.
  • A narrower and more specific definition of biotechnology is “the commercial application of living organisms or their products, which involves deliberate manipulation of their DNA molecules.”
  • This definition implies a set of laboratory techniques developed within the last 20 years that have been responsible for the tremendous scientific and commercial interest in biotechnology.
  • Some other available definitions of biotechnology are as follows:
    • “The application of biological organisms, systems, or processes to manufacturing and service industries.” British Biotechnologist
    • “The integrated use of biochemistry, microbiology, and genetic engineering sciences in order to achieve technological (industrial) application of capabilities of microorganisms, cultured tissue cells, and parts thereof.”-European Federation of Biotechnology
    • “Controlled use of biological agents such as microorganisms and cellular components for beneficial use.” US National Science Foundation
  • The development of biotechnology can be studied considering its growth that occurred in two phases: (a) Traditional (old) biotechnology and (b) new (modern) biotechnology.

Read and Learn More NEET Biology Notes

Traditional Biotechnology

  • Traditional biotechnology includes processes that are based on the natural capabilities of microorganisms.
  • It is also called conventional technology; it has been used for many centuries.
  • Curd; vinegar; ghee; wine, beer, and other alcoholic beverages; and idli, dosa, cheese, paneer, and some other foods have been produced using traditional bio-technology.
  • In Indian Ayurveda, the production of asva, arista, etc., is done through traditional biotechnology.
  • According to some people, traditional biotechnology is, therefore, an art rather than a science.

Modern Biotechnology

  • When extremely new and useful traits in crop varieties and animal breeds are created with the help of genetic engineering, it is called modern biotechnology.
  • It was developed in 1970.
  • For example, in vitro fertilization leading to a “test tube baby,” synthesizing a gene and using it, developing a DNA vaccine, or correcting a defective gene are all parts of modern biotechnology.
  • Among many, the two main techniques that gave birth to modern biotechnology are as follows:
    • Genetic engineering: The techniques which change the chemistry of genetic material (DNA and RNA) to introduce these into host organisms and, thus, alter the phenotype of the host organism are called genetic engineering (recombinant DNA technology).
    • To maintain microbial contamination-free (sterile) surrounding in chemical engineering: Due to such type of maintenance, only desired microorganisms/cells will be formed in large number for the manufacture of biotechnological products such as antibiotics, vaccines, enzymes, hormones, and blood clotting factors. It is essential to have complete aseptic conditions.

Concept of Genetic Engineering

  • Combining DNA from different existing organisms such as plants, animals, and bacteria results in modified organisms with a combination of traits from the parents.
  • This sharing of DNA information occurs naturally through sexual reproduction and has been exploited in plant and animal breeding for a number of years.
  • However, sexual reproduction (recombination) can occur between the individuals of same species. Genetic engineering is the manipulation of prokaryotic as well as eukaryotic DNA.
  • It involves the breakage of a DNA molecule at two de- sired places to isolate a specific DNA segment which is then inserted in another DNA molecule at a desired position.
  • The product, thus, obtained is called recombinant DNA and the technique is often called genetic engineering.
  • The cutting of the DNA at specific locations became possible by so called “molecular scissors,” i.e., restriction enzymes.
  • In chromosomes, there is a specific “ori” site or the origin of replication which initiates the replication.
  • Therefore, for the duplication of any foreign DNA in an organism, it should be linked with the ori sites so that the foreign DNA can duplicate and multiply within the organism.
  • This is called gene cloning. Multiple copies of any template DNA can be produced by using gene cloning.
  • The construction of the first recombinant DNA emerged from the possibility of linking a gene encoding antibiotic resistance with a native plasmid (autonomously replicating circular extra-chromosomal DNA) of Salmonella typhimurium.
  • Stanley Cohen and Herbert Boyer accomplished this in 1972 by isolating the antibiotic resistance gene by cutting out a piece of DNA from a plasmid which was responsible for conferring antibiotic resistance.
  • These plasmid DNA molecules act as vectors to transfer the piece of DNA attached to it.
  • As mosquito acts as an insect vector to transfer the malarial parasite into human body, in the same way, a plasmid can be used as a vector to deliver an alien piece of DNA into the host organism.
  • The linking of antibiotic resistance gene with the plasmid vector became possible with enzyme DNA ligase, which acts on cut DNA molecules and joins their ends.
  • This makes a new combination of circular autonomously replicating DNA created in vitro known as recombinant DNA.
  • When this DNA is transferred into Escherichia coli, a bacterium closely related to Salmonella, it replicates using the new host’s DNA polymerase enzyme and makes multiple copies.
  • The ability to multiply copies of antibiotic resistance gene in E. coli was called cloning of antibiotic resistance gene in E. coli.
  • Therefore, there are three basic steps in genetically modifying an organism:
    • Identification of DNA with desirable genes.
    • Introduction of the identified DNA into the host.
    • Maintenance of introduced DNA in the host and transfer of the DNA to its progeny.

” biological molecules”

Tools Of Recombinant DNA Technology

The technology or genetic engineering involves restriction enzymes, ligase enzymes, polymerase enzymes, vectors, and the host organism.

Restriction Enzymes

  • In the late 1960’s, scientists Stewart Linn and Werner Arber isolated samples of two types of enzymes responsible for phage growth restriction in E. coli bacteria.
  • One of these enzymes was methylated DNA while the other was cleaved unmethylated DNA at a wide variety of locations along the length of the molecule. The first type of enzyme was called methylase while the other was called restriction nuclease.
  • These enzymatic tools were important for scientists who were gathering the tools needed to “cut and paste” DNA molecules.
  • What was needed now was a tool that would cut DNA at specific sites, rather than at random sites along the length of the molecule, so that scientists can cut DNA- molecules in a predictable and reproducible way.

Site-Specific Nuclease

  • This important development came when H.O. Smith, K.W. Wilcox, and T.J. Kelley isolated and characterized the first restriction nuclease whose functioning depended on a specific DNA nucleotide sequence.
  • Working with Haemophilus influenzae bacteria, this group isolated an enzyme called Hind II that always cut DNA molecules at a particular point within a spe- cific sequence of six base pairs.
  • This sequence is
    • 5′ GT (pyrimidine: T or C) (purine: A or G) AC 3′
    • 3′ CA (purine: A or G) (pyrimidine: T or C) TG 5′
  • They found that Hind II enzyme always cuts directly in the center of this sequence.
  • Wherever this particular sequence of six base pairs occurs unmodified in a DNA molecule, Hind II will cleave both DNA strands or backbones between the third and the fourth base pairs of the sequence.
  • Moreover, Hind II will cleave both DNA strands or backbones between the third and the fourth base pairs of the sequence will only cleave a DNA molecule at this particular site. For this reason, this specific base sequence is known as the “recognition sequence” for Hind II.
  • Hind II is just one example of the class of enzymes known as restriction nucleases.
  • In fact, more than 900 restriction enzymes, some sequences specific and some not, have been isolated from over 230 strains of bacteria since the initial discovery of Hind II.
  • These restriction enzymes generally have names that reflect their origin.
  • The first letter (in italics) of the name comes from the genus and the second two letters (in italics) come from the species of the prokaryotic cell from which they were isolated.
  • Next is the strain of the organism and last is the Roman numeral indicating the order of discovery (the order in which the enzymes were isolated from single strains of bacteria).
  • For example, Eco RI comes from Escherichia coli RY strain (and was the first endonuclease isolated from bacteria) while Hind II comes from Haemophilus in- fluenzae strain Rd.
  • Nucleases are further described by the addition of the prefix “endo” or “exo” to the name. The term “endonuclease” applies to sequence-specific nucleases that break nucleic acid chains somewhere in the interior, rather than at the ends of the molecule.
  • Nucleases that function by removing nucleotides from the ends of the molecules are called exonucleases.
  • Three main classes of restriction endonucleases: type 1, type 2, and type 3, have been described, each distinguished by a slightly different mode of action.
  • Out of these three types, type 1 and type 3 restriction enzymes are not used in recombinant DNA technology.
  • Type 2 restriction enzymes are used in recombinant DNA technology, because they can be used in vitro to recognize and cut within the specific DNA sequence typically consisting of 4-8 nucleotides.
  • Type 1 enzymes recognize specific sites within the DNA but do not cut at these sites.
  • Hence, heterogeneous population of DNA fragments is produced. Therefore, type 1 enzymes do not take part in the technology. Type 3 enzymes recognize a specific sequence of DNA molecule. Thus, the products of type 3 enzymes are homogeneous population of DNA fragments; so, they cannot be used for genetic engineering experiments.
  • The DNA segments cut by restriction enzymes are palindromic, i.e., the nucleotide sequences of these DNA pieces read the same both backwards and forward when the orientation of reading is kept same, e.g., madam.
  • Blunt or flush ends are produced by many restriction enzymes which cleave both strands of DNA at exactly the same nucleotide position-in the center of recognition site. For example, Small recognizes six-nucleotide palindromic sequence.
  • It cuts both DNA strands producing blunt ends.
  • Sticky or cohesive ends are produced when restriction enzymes do not cut DNA at the same nucleotide position but cut the recognition sequence unequally. This produces short, single-stranded overhangs at each end. These are known as sticky ends. For example, Eco RI recognizes 6-nucleotide palindromic sequence.

NEET Biology Bio-Technology Principles And Process Action of restriction enzymes

  • This restriction endonuclease cuts both DNA strands unequally, producing 5′ overhangs of four nucleotides.
  • The stickiness helps enzyme ligase to make the DNA pieces join.

” biomolecules structure”

NEET Biology Bio-Technology Principles And Process Action of restriction enzyme

Other Enzymes Used in Recombinant DNA Technology

  • In addition to restriction enzymes, there are several other enzymes that play an important role in DNA technology.
  • Three of the important ones are DNA ligase, alkaline phosphatase, and DNA polymerase.
    • DNA ligase: This enzyme forms phosphodiester bonds between adjacent nucleotides and covalently links two individual fragments of double-stranded DNA. The action of ligase enzyme requires a phosphate group at the 5′ carbon of one nucleotide and a hydroxyl group at the 3′ carbon of the adjacent nucleotide to form phosphodiester bond between these two nucleotides. The enzyme used most often in the rDNA technology is T4 DNA ligase, which is encoded by phage T4.
    • Alkaline phosphatase (AP): As mentioned above, ligation absolutely requires the presence of 5′ phosphate group at the DNA site to be ligated. If this phosphate group is removed, this DNA can- not be ligated. The enzyme alkaline phosphatase is used to remove the phosphate group from the 5′ end of a DNA molecule, leaving a free 5′ hy- droxyl group. This enzyme can be isolated from bacteria (BAP) or calf intestine (CAP). It is used to prevent unwanted self-ligation of vector DNA molecules in the procedures of rDNA technology.
      However, the ligation of the vector to the insert can occur as the insert still has its 5′ phosphate.
    • DNA polymerase: DNA polymerase I (DNA Pol I) enzyme polymerizes DNA synthesis on DNA template or complementary DNA (cDNA). It also catalyzes 5′ 3′ and 3′ 5′ exonucleolytic degradation of DNA. The other two enzymes are DNA Pol II and DNA Pol III. These have almost similar catalytic activity. DNA Pol III is about several times more active than the other two. Where there is preformed DNA template, it pro- duces a parallel strand in the presence of ATP.

Separation and Isolation of DNA Fragments

  • After the cutting of DNA by restriction enzymes, fragments of DNA are formed.
  • These fragments can be separated by a technique called gel electrophoresis.
  • Electrophoresis is a technique of separation of charged molecules under the influence of an electrical field so that they migrate in the direction of the electrode bearing opposite charge, i.e., positively charged molecules move towards cathode (-ve electrode) and negatively charged molecules travel towards anode (+ve electrode), through a medium/matrix.
  • This technique was developed by A. Tiselius in 1937.
  • Nowadays, the most commonly used matrix is agarose which is a polysaccharide extracted from sea weeds.
  • DNA fragments separate according to size through the pores of agarose gel.
  • Hence, the smaller the fragment size, the farther it moves.
  • Agarose dissolves in hot water. When this solution is cooled, double helices form. These become arranged laterally and produce thick filaments.
  • These filaments become cross-linked to form the gel.
  • Pore size depends on agarose concentration.

NEET Biology Bio-Technology Principles And Process Formation of pores in agarose gel

  • Separated DNA fragments can be seen only after staining the DNA with a compound ethidium bromide followed by exposure to UV radiations as bright orange colored bands. The separated bands of DNA are cut out from the agarose gel and extracted from the gel piece. This step is called elution. Several techniques are used for eluting the DNA from the gel piece. These purified DNA fragments are used in the formation of recombinant DNA by linking them with cloning vectors.

NEET Biology Bio-Technology Principles And Process A typical agarose gel electrophoresis

  • Cloning vectors: Another important tool for genetic engineering is the vehicle for cloning, called vector. A vector carries a foreign DNA sequence into a given host cell. Bacterial plasmids and bacteriophages are considered the most useful. This is because of the following reasons:
    • These are independent of the control of chromosomal DNA.
    • Bacteriophage genomes occur in very large numbers in bacterial cells.
    • The copies of plasmids per cell range from only a few to hundred or even more.

NEET Biology Bio-Technology Principles And Process Joining of DNA fragments

  • Certain essential features should be present in a DNA molecule to act as a cloning vector.
    • Origin of replication (ori): This is a DNA sequence which serves as a starting point for replication. When a DNA fragment gets associated with ori, foreign DNA into the vector would also replicate inside the host cell. Some vectors possess origin which favors the formation of high copy numbers and, hence, are preferred.
    • Selectable marker: A vector should also include a selectable marker. This is a gene which would permit the selection of host cells containing vector from amongst those which do not possess vector. Common selectable markers include genes encoding antibiotic resistance such as ampicillin resistance or enzymes such as ẞ-galactosidase (product of lac Z gene of lac operon). These genes can be identified by a color reaction.
    • Recognition sites: A vector should possess a unique restriction site that would allow a particular enzyme to cut the vector only once. This site would be recognized by the commonly used restriction enzymes. If there are more than one recognition sites in a vector, several fragments would be produced. Generally, the vectors used possess unique recognition sites for several restriction enzymes in a small region of DNA. This is known as polylinker or multiple cloning site (MCS). Such cloning site offers a choice of restriction enzymes. Unique restriction endonuclease recognition site enables the insertion of foreign DNA into the vector for the production of recombinant DNA. The foreign DNA is inserted and made to join (ligate) at a specific restriction site, generally, in antibiotic resistance gene.
    • pBR322 has genes for resistance against two antibiotics (tetracycline and ampicillin). An origin of replication and a variety of restriction sites for cloning of restriction fragments are obtained through cleavage with a specific enzyme. Foreign DNA is inserted at a site located in one of the two genes for resistance against antibiotics, so that it will inactivate one of the two resistance genes.
    • The insert bearing plasmids can be selected by their ability to grow in a medium containing only one of the two antibiotics and their failure to grow in a medium containing both antibiotics. The plasmids carrying no insert, on the other hand, will be able to grow in a media containing one or both antibiotics. In this way, the presence of resistance genes against ampicillin and tetracycline allows the selection of Escherichia coli colonies transformed with plasmids carrying the desired foreign cloned DNA fragment.
    • Size of the vector: The cloning vector should be small in size. Large molecules have a tendency to break down during purification. These are also difficult to manipulate.

Different Types Of Vectors

Several types of vectors satisfying the above characters have been developed. The following are some of the commonly used vectors.

Plasmids

  • These are extra-chromosomal, non-essential self-replicating, usually circular, and double-stranded DNA molecules occurring in some bacteria and also a few yeasts.
  • Some of the characters carried by plasmids may not be required for normal bacterial metabolism but may be of great advantage, e.g., antibiotic resistance.
  • pBR322 is one of the standard cloning vectors widely used in gene cloning experiments.
  • This vector has been restructured by inserting genes for antibiotic resistance.
  • It is named after Boliver and Rodriguez who prepared this vector.

” types of biomolecules “

NEET Biology Bio-Technology Principles And Process Different types of vectors

  • PUC (named after the University of California) is another such reconstructed plasmid vector.
  • The vectors mentioned above are able to replicate only in E. coli.
  • Therefore, many vectors constructed for eukaryotic cells are also functional in E. coli.
  • These vectors are called shuttle vectors.
  • The vectors contain two types of origin of replication and selectable marker genes one for the eukaryotic cell and the other for E. coli.
  • The common example of this type is yeast episomal plasmid (Yep).
  • In plants, tumor-inducing (Ti) plasmid of bacterium Agrobacterium tumfaciens has been modified to function as a vector.

Vectors Based on Bacteriophages

Bacteriophages are viruses which infect bacterial cells, produce new phages inside the host bacterium, and are released from the host cell to again infect other bacterial cells. M13 and lambda (2) phages are in common use.

Cosmids

Cosmids combine some features of plasmid and cos (cohesive end sites) of phage lambda (cosmid = cos + plasmid).

Yeast Artificial Chromosome Vectors

Yeast artificial chromosome (YAC) contains telomeric sequence, centromere, and autonomously replicating sequence from yeast chromosomes. It also has suitable restriction enzyme sites and genes useful as selectable markers.

Bacterial Artificial Chromosome Vectors

  • Bacterial artificial chromosome (BAC) is based on the F-plasmid (fertility) of E. coli. It contains genes for the replication and maintenance of F-factor, selectable marker, and cloning sites.
  • Color reaction: Due to the inactivation of antibiotics, the selection of recombinants becomes a burdensome process because it requires simultaneous plating on two plates having different antibiotics. Thus, an alternative selectable marker is developed to differentiate recombinants and non-recombinants on the basis of their ability to produce color in the presence of a chromogenic substance. Now, a recombinant DNA is inserted in the coding sequence of enzyme ẞ-galac-tosidase. This causes the inactivation of the enzyme; it is called insertional inactivation. If the plasmid in the bacterium does not have an insert, the presence of a chromogenic substrate gives blue-colored colonies. The presence of insert results in the insertional inac- tivation of B-galactosidase. Therefore, the colonies do not produce any color. These colonies are marked as recombinant colonies.

Vectors for Cloning Genes in Plants and Animals

  • We know the procedure of transferring genes into plants and animals from bacteria and viruses.
  • The procedure to transfer genes to transform eukaryotic cells and force them to do what the bacteria or viruses require is also known.
  • For example, Agrobacterium tumifaciens, a pathogen (disease causing agent) of several dicot plants, is able to transfer a piece of DNA known as T-DNA to convert normal plant cells into tumor and direct these tumor cells to secrete the chemicals required by the pathogen. Similarly, retroviruses (cause leukosis or sarcoma types of cancer) in animals including humans are able to change normal cells into cancerous cells.
  • The Ti plasmid of Agrobacterium tumifaciens has been modified into a cloning vector which is not pathogenic to plants. However, it is still able to use the procedure to deliver genes of our interest into various plants.
  • Similarly, retroviruses are used to carry desirable genes into animal cells.
  • Thus, once a gene or DNA fragment is joined to a suitable vector, it is transferred into a bacterial plant or animal host where it undergoes multiplication.

Host Cell

  • Competent host cell is required for transformation with recombinant DNA.
  • After the formation of recombinant DNA, propagation of it must occur inside a living system or a host.
  • Different types of available host cells are E. coli, yeast, and animal and plant cells.
  • The type of host cell to be used depends on the aim of cloning experiment.
  • Eukaryotic cells will be the preferred host for the expression of some eukaryotic proteins.
  • Yeast cells are preferred because these are the simplest eukaryotic organisms and, like bacteria, are single celled, genetically well characterized, and easy to grow and manipulate.
  • Plant and animal cells can be used for protein expression either in tissue culture or as cells in the whole organism to create genetically modified (GM) crops and animals.
  • As DNA is a hydrophilic molecule, it cannot pass through cell membrane.
  • Therefore, the bacterial cells should be capable of up- taking DNA.
  • This is accomplished by treating them with specific concentration of a divalent cation, e.g., Ca2+, making them competent which causes an efficient entry of DNA into the bacterium through the pores in its cell wall.
  • Recombinant DNA can be forced into such cells by incubating the cells with recombinant DNA on ice, followed by placing them briefly at 42°C (heat shock), and then putting them back on ice. As a result, bacteria get enabled to pick up recombinant DNA.
  • There are other methods to introduce foreign DNA into host cells. These are briefly described in the following subsections.

Microinjection

  • In the microinjection method, the recombinant DNA is directly injected into the nucleus of animal cell by using micro-needles or micro-pipettes. It is used in oocytes, eggs, and embryo. Jeffey S. Chamberlain et. al. (1993) of Human Genome Center, Michigan University, USA, have cured mice that inherited a neuromuscular disease which is like the muscular dystrophy of humans.

Direct DNA Injection

Direct injection of DNA into skeletal muscle led to the possibility of using gene as vaccines. Due to low level of expression, therapeutic benefits for the treatment of genetic disorder could not be derived. This method gave birth to the concept of DNA vaccine or genetic immunization.

Gene Gun or Biolistics

New technologies such as gene gun are also available for vector-less direct gene transfer. DNA coated onto microscopic pellets is literally shot into target cells. Although it is developed for plants, it is also used for animal cells for promoting tissue repair or reducing healing time. This method made great impact in the field of vaccine development.

NEET Biology Bio-Technology Principles And Process Gene gun

Process Of Recombinant DNA Technology

Recombinant technology is a complicated process. Several steps lead to the desired goal. The major steps are as follows:

  • Isolation of DNA
  • Digestion of DNA by restriction endonuclease enzyme
  • Gene amplification
  • Introduction of recombinant DNA into host cells.
  • Identification of recombinants
  • Gene product manufacture
  • Processing

” introduction to biomolecules “

Isolation of DNA: Isolation of the Genetic Material (DNA)

  • Nucleic acid (DNA or RNA) is the genetic material of all organisms. It is DNA in majority of organisms.
  • For cutting the DNA with restriction enzymes, it needs to be pure and free from other macromolecules.
  • Because DNA is covered with membranes, it has to break the cell open to release DNA and other macro-molecules such as RNA, proteins, polysaccharides, and lipids.
  • It is obtained by treating the bacterial cells/plant or animal tissues with enzymes such as lysozyme (bacteria), cellulase (plant cells), and chitinase (fungus).
  • As we know that genes are present on long molecules of DNA intertwined with proteins such as histones, RNA can be removed by treating with ribonuclease while proteins can be removed by treating with protease.
  • Other molecules are removed by proper treatments. Purified DNA finally precipitates out after the addition of chilled ethanol.
  • This is seen as a collection of fine threads in suspension.

NEET Biology Bio-Technology Principles And Process Isolation of DNA

DNA Digestion by Restriction Enzymes

  • The vector and the target DNA fragment can be separately digested with the same restriction enzyme.
  • The digested vector and the target DNA fragment are then incubated together in the presence of DNA ligase enzyme.

NEET Biology Bio-Technology Principles And Process DNA digestion by ECO RI ligase

  • Incubation results in bonding of two types of DNA by phosphodiester bonds between them.
  • Thus, the deoxyribose-phosphate backbones of vector molecule and the target DNA fragment are covalently linked, forming a recombinant DNA molecule.
  • Another possibility in this experiment is the rejoining of the sticky ends of the vector molecule itself, forming a circular vector DNA molecule that is without foreign DNA molecule.
  • This possibility is eliminated by treating digested vector with alkaline phosphatase or by using different restriction enzymes.

biomolecules protein

Gene Amplification

  • Gene amplification is the process of selective multiplication of a specific region of DNA molecule.
  • The process has also been used to produce DNA fragments for cloning.
  • Amplification is achieved by a special method known as polymerase chain reaction (PCR) developed by Kary Mullis in 1985 for which he shared Nobel Prize in 1993.
  • The principle underlying the technique is to heat double-stranded DNA molecule to a high temperature so that the two DNA strands separate into single-stranded DNA molecules.
  • If these single-stranded molecules are copied by a DNA polymerase, it would lead to the duplication of the original DNA molecule; if these events are repeated many times, then multiple copies of the original DNA sequence can be generated.
  • The basic requirements of a PCR reaction are as follows:
    • DNA template: Any source that contains one or more target DNA molecules to be amplified can be taken as a template.
    • Primers: Primers, which are oligo-nucleotides, usually 10-18 nucleotides long, hybridize to the target DNA region, one to each strand of the double helix. Two primers are required and these primers are oriented with their ends facing each other, allowing the synthesis of the DNA towards one another.
    • Enzyme: DNA polymerase which is stable at high temperatures (>90°) is required to carry out the synthesis of new DNA. The polymerase which is generally used in PCR reactions is Taq polymerase (isolated from bacterium Thermus aquaticus). Other thermostable polymerases can also be used.

NEET Biology Bio-Technology Principles And Process Schematic representation of the three steps performed during PCR

Working Mechanism of PCR

  • A single PCR amplification cycle involves three basic steps: denaturation, annealing, and extension (polymerization).
    • Denaturation: In the denaturation step, the tar- get DNA is heated to a high temperature (usually 94°C), resulting in the separation of the two strands. Each single strand of the target DNA then acts as a template for DNA synthesis.
    • Annealing: In this step, the two oligo-nucleotide primers anneal (hybridize) to each of the single- stranded template DNA since the sequence of primers is complementary to the 3′ ends of template DNA. This step is carried out at a lower temperature depending on the length and sequence of the primers.
    • Primer extension (polymerization): The final step is extension, wherein Taq DNA polymerase (of a thermophilic bacterium Thermus acquaticus) synthesizes the DNA region between the primers, using dNTPs (deoxynucleoside triphosphates) and Mg2+. It means the primers are extended towards each other so that the DNA segment lying between the two primers is copied. The optimum temperature for this polymerization step is 72°C. To begin the second cycle, the DNA is again heated to convert all newly synthesized DNA into single strands, each of which can now serve as a template for the synthesis of more new DNA. Thus, the extension product of one cycle can serve as a template for subsequent cycles and each cycle essentially doubles the amount of DNA from the previous cycle. As a result, from a single template molecule, it is possible to generate 2″ molecules after n number of cycles.

Application of PCR

Some of the areas of application of PCR are briefly mentioned here.

  • Diagnosis of pathogens: Pathologists use techniques based on detecting specific enzymes or antibodies against disease-related proteins. But these techniques cannot be used for detecting infectious agents that are difficult to culture or that persist at very low levels in infected cells. To overcome these problems, PCR-based assays have been developed that detect the presence of gene sequences of infectious agents.
  • Diagnosis of specific mutation: PCR can be used to detect the presence of a specific mutation that is r sponsible for causing a particular genetic disease be- fore the actual onset of the disease. By using PCR, phenylketonuria, muscular dystrophy, sickle-cell anemia, AIDS, hepatitis, Chlamydia, and tuberculosis can be diagnosed.
  • DNA fingerprinting: PCR is of immense value in generating abundant amount of DNA for analysis in the DNA fingerprinting technique used in forensic science to link a suspect’s DNA to the DNA recovered at a crime scene.
  • Detection of specific microorganisms: PCR is also used for detecting specific microorganisms from the environment samples of soil, sediments, and water.
  • In prenatal diagnosis: It is useful to detect a genetic disease in fetus before birth. If the disease is not curable, abortion is recommended.
  • Diagnosis of plant pathogens: Many diseases of plants can be detected by using PCR. For example, viroids (associated with apple, grape, citrus, pear, etc.), viruses (such as TMV and bean yellow mosaic virus), bacteria, mycoplasmas, etc.
  • In paleontology: PCR is used to clone the DNA fragments from the mummified remains of humans and extinct animals such as wooly mammoth and dinosaurs.

NEET Biology Bio-Technology Principles And Process Comparison between PCR and gene cloning

NEET Biology Bio-Technology Principles And Process Comparison between PCR and gene cloning 1

NEET Biology Bio-Technology Principle And Processes PCR Techniques for obtaining multiple copies of DNA

Introduction of Recombinant DNA into Host Cells

  • Once the recombinant DNA molecule has been multiplied, it needs to be inserted into host cells.
  • Many methods for introduction are available.
  • The selection of a method depends upon the type of vector and the host cell along with other things.
  • Some common methods are as follows:
    • Transformation: This is a method where cells take up DNA from their surroundings. Since many cells such as those of E. coli, yeast, and mammals do not naturally absorb DNA, they need to be made competent. Mandel and Higa (1970) observed that E. coli cells can be made competent to take up external DNA by suspending them in cold calcium chloride.

” carbohydrates biomolecules”

NEET Biology Bio-Technology Principles And Process Transformation in bacterial cell

    • Transfection: In this method, DNA is mixed with charged substances such as calcium phosphate and cationic liposomes. These are spread on the recipient host cells. Calcium ions carry foreign DNA and release it inside the cell since calcium gets precipitated in the form of calcium phosphate, thus, transferring the DNA by endocytosis.
    • Microinjection and macroinjection: Specially designed micromanipulator is used to inject DNA into cytoplasm or the nucleus of a recipient cell or protoplast. The method is used for the direct introduction of DNA into plant or animal cells without using special eukaryotic vectors.

NEET Biology Bio-Technology Principles And Process Microinjection

    • Microprojection (biolistics or particle gun): Tungsten or gold particles (microparticles) coated with DNA are accelerated to a very high initial velocity. These microprojectiles are carried by other (nylon) microprojectiles or the bullet, causing them to penetrate the cell walls of intact target cells or tissues.

NEET Biology Bio-Technology Principles And Process Schematic representation of microprojectile gun

    • Electroporation: Short electrical impulses of high field strength are given. These increase the permeability of protoplast membrane by creating transient microscopic pores, thus, making the entry of DNA molecules into the cells much easier.
    • Ti plasmid based gene transfer:
      • A more common method of introducing foreign DNA into plant cells is to use the bacterium Agrobacterium tumefaciens and its Ti plasmid.
      • This Gram-negative soil bacterium is a plant pathogen and produces crown gall disease in many dicotyledons including grapes, stone fruits, roses, tomato, sunflower, cotton, soybean, etc.
      • Most strains of this bacterium carry Ti plasmid.
      • In nature, Agrobacterium attaches to the leaves of plants and Ti plasmid is transferred into plant cells.
      • The plasmid becomes incorporated into plant chromosomal DNA.
      • Therefore, Ti plasmid has been used as a vehicle for the introduction of recombinant DNA into plant cells.
      • Ti plasmids cause tumors in plants.
      • Strains of the bacterium have been developed which do not have tumor-inducing genes. However, the T-region of plasmid plays an important role in gene transfer.
      • This specific segment of bacterial plasmid DNA is called T-DNA (transferred DNA).
      • T-DNA has a cloning site into which foreign DNA (DNA insert) is inserted.
      • This recombinant plasmid is now introduced into bacterium Agrobacterium tumefaciens. It is then used to infect cultured cells.
      • The T-region of the plasmid with foreign DNA (or DNA insert) is transferred to plant cells.
      • It gets integrated with the chromosomal DNA of the cell.
      • Cultured cells are induced to grow into plantlets.
      • These are planted into the soil where mature plants are formed.

NEET Biology Bio-Technology Principles And Process Ti plasmid based gene transfer

Identification of Recombinant

  • After the insertion of recombinant DNA into the host cell, these need to be identified from those which do not possess it.
  • The methods used to do so consider expression or non- expression of certain characters especially antibiotic resistance gene (e.g., ampicillin resistance gene) on plasmid vector.
  • Selectable marker usually provides resistance against a substrate which when added to the culture medium inhibits the growth of normal cells or tissues in culture, so that only transformed tissues will grow.

NEET Biology Bio-Technology Principles And Process Selection of transgenic cells

  • Thus, the simplest method for identification is to grow transformed host cells (with ampicillin resistance gene) on medium containing ampicillin.
  • This would enable the cells containing this trans- formed plasmid to grow and form colonies.
  • There are other methods for the detection of recombinants based on the fact that the cloned DNA fragment disturbs the coding sequence of gene.
  • This is known as insertional inactivation.
  • Let us consider a plasmid containing genes resistant for two different antibiotics: ampicillin and tetracycline.
  • If the target DNA fragment is inserted in a site located in ampicillin resistance gene, this gene will then be in-activated.
  • Thus, host cells with such a recombinant plasmid will be sensitive to ampicillin but resistant to tetracycline.
  • These host cells will die when grown on ampicillin containing medium but would grow on medium containing tetracycline.
  • Self-ligated or religated (non-recombinant) vectors would grow on medium containing both ampicillin and tetracycline, being resistant to them.
  • Another, but similar, method involves insertional inactivation of the lac Z gene.
  • It is known as blue-white selection, being color based.

Gene Product Manufacture

  • When recombinant DNA is transferred into a bacterial, plant, or animal cell, the foreign DNA is multiplied.
  • Most of the recombinant technologies are aimed to produce a desirable protein.
  • So, there is a need for expression recombinant DNA. After the cloning of the gene of interest, one has to maintain the optimum conditions to induce the expression of the target protein and consider producing it on a large scale.
  • If any protein encoding gene is expressed in a heterologous host, it is known as a recombinant protein.
  • The cells having cloned genes of interest can be grown on a small scale in the laboratory.
  • Cultures may be used for extracting and purifying the desired protein.
  • The cells can also be multiplied in a continuous system where the used medium is passed out from one side and the fresh medium is added from the other side to maintain the cells in their physiologically most active lag exponential phase (lag phase: no significant increase of cells; exponential phase: rapid multiplication of cells).
  • This type of culturing method produces a larger biomass to get higher yields of the desired protein.
  • Small volume cultures cannot give large quantities of products.
  • To produce large quantities of these products, the development of bioreactors is required where large volumes (100-1000 L) of culture can be processed. Hence, bioreactors are like vessels in which raw materials are biologically converted into specific products (individual enzymes) using microbial, plant, animal, or human cells.
  • A bioreactor provides the optimal conditions for obtaining the desired product by providing optimum growth conditions such as substrate, temperature, pH, vitamins, oxygen, and salts.
  • One of the most commonly used bioreactor is of stirring type.
  • A stirred reactor is usually cylindrical with a curved base to allow mixing of the contents of the reactor.
  • The presence of stirrer makes mixing possible and also makes oxygen available through the reactor.
  • A bioreactor also has an agitatory system, an oxygen delivery system, a foam control system, a temperature control system, pH control system, and sampling ports so that small volumes of culture can be withdrawn periodically.

NEET Biology Bio-Technology Principles And Process Simple stirred tank bioreactor

Downstream Processing

  • Once the product is ready, it has to be processed for commercial use.
  • This requires purification and strict quality control to maintain the efficacy.
  • The products based on biotechnology must ensure that they satisfy the consumer needs and are not harmful.
  • Therefore, a thorough checking of products at each level of manufacture is done.
  • The manufacturing process and the quality control methods vary with each product.

Choose the correct answer:

Question 1. 3′-5′ exonucleolytic degradation of DNA is performed by which enzyme?

  1. DNA polymerase
  2. Alkaline phosphatase
  3. DNA ligase
  4. RNA polymerase

Answer. 1. DNA polymerase

Question 2. The technique of gel electrophoresis was developed by

  1. Kary Mullis
  2. J.S. Chamberlain
  3. A. Tiselius
  4. F. Sanger

Answer. 3. A. Tiselius

Question 3. Which of the following dyes can be used to visualize nucleic acid after electrophoresis?

  1. Acridine orange
  2. Ethidium bromide
  3. Bromophenol blue
  4. Both (1) and (2)

Answer. 4. Both (1) and (2)

Question 4. Which of the following bonds are formed by the action of DNA ligase?

  1. Sugar-phosphate bond
  2. Phosphodiester bond
  3. Both (1) and (2)
  4. Phosphate-phosphate bond

Answer. 3. Both (1) and (2)

Question 5. Who were responsible for the isolation of “methylase” kind of enzyme from E. coli in 1960’s?

  1. Cohen and Boyer
  2. Banting and Best
  3. Linn and Arber
  4. Smith and Wilcox

Answer. 3. Linn and Arber

Question 6. The specific sequence recognized by “molecular scissors” is called

  1. Isomer
  2. Isobar
  3. Misnomer
  4. Palindrome

Answer. 4. Palindrome

Question 7. When a piece of DNA is digested with Eco RI, what kind of ends are created?

  1. Blunt ends
  2. Flush ends
  3. Cohesive ends
  4. Non-staggered ends

Answer. 3. Cohesive ends

Question 8. The sticky ends generated by the action of Eco RI on insert DNA facilitate the action of which enzyme?

  1. DNA polymerase
  2. Taq polymerase
  3. Alkaline phosphatase
  4. DNA ligase

Answer. 4. DNA ligase

Question 9. Which is incorrect with respect to DNA polymerase III?

  1. It requires ATP for polymerase action.
  2. It is required for PCR.
  3. It is more active than DNA polymerases I and II.
  4. It requires a pre-formed DNA template to work on.

Answer. 2. It is required for PCR.

Question 10. Which is not an application of modern biotechnology?

  1. Production of humulin
  2. Developing a DNA vaccine
  3. Gene therapy
  4. Production of cheese and butter

Answer. 4. Production of cheese and butter

Question 11. Which of the following cannot be related to biotechnology?

  1. Integration of natural science and organisms.
  2. Techniques to alter the chemistry of DNA.
  3. Introducing undesirable genes into the target organism.
  4. Maintenance of sterile ambience to enable the growth of only the desired microbes.

Answer. 3. Introducing undesirable genes into the target organism.

Question 12. Which of the following specific DNA sequence is responsible for initiating replication?

  1. Vector site
  2. Restriction enzymes action site
  3. Ori site
  4. Palindromic site

Answer. 3. Ori site

Question 13. Autonomously replicating, circular, extra chromosomal DNA of prokaryotic cell is called

  1. Satellite DNA
  2. Plasmid
  3. Recombinant DNA
  4. Nucleoid

Answer. 2. Plasmid

Question 14. Key tools to be involved in recombinant DNA technology are

A. Restriction enzymes

B. Polymerase enzyme

C. Ligase enzymes

D. Vectors

  1. (A) only
  2. (A) and (C) only
  3. (A), (B), and (C)
  4. (A), (B), (C), and (D)

Answer. 4. (A), (B), (C), and (D)

Question 15. The first restriction endonuclease to be discovered was

  1. Hind II
  2. Eco RI
  3. Bam HI
  4. Pst I

Answer. 1. Hind II

Question 16. Approximately, how many restriction enzymes have been isolated from the different (over 230) strains of bacteria?

  1. 300
  2. 600
  3. 750
  4. 900

Answer. 4. 900

Question 17. The conventional method for naming restriction enzymes is followed. In case of Eco RI, the “R” indicates

  1. Genus
  2. Species
  3. Name of the scientist
  4. Strain

Answer. 4. Strain

Question 18. The restriction endonuclease enzyme binds to the DNA and cuts

  1. Any one strand of the double helix
  2. Each of the two strands at specific points in their base-sugar bonds
  3. Each of the two strands at specific points in their base-phosphate bonds
  4. Each of the two strands at specific points in their sugar-phosphate backbones

Answer. 4. Each of the two strands at specific points in their sugar-phosphate backbones

Question 19. During gel electrophoresis, for the separation of DNA fragment, the

  1. Smallest fragment will move to the farthest point towards cathode
  2. Smallest fragment will move to the farthest point towards anode
  3. Largest fragment will move to the farthest point towards cathode
  4. Largest fragment will move to the farthest point towards anode

Answer. 2. Smallest fragment will move to the farthest point towards anode

Question 20. After electrophoresis, the separated DNA fragment can be visualized in ethidium bromide gel exposed to UV light. These DNA fragments appear as _________ colored bands.

  1. Orange
  2. Blue
  3. Silver
  4. Green

Answer. 1. Orange

Question 21. The procedure through which a piece of DNA is introduced in a host bacterium is called

  1. Cloning
  2. Transformation
  3. PCR
  4. Clonal selection

Answer. 2. Transformation

Question 22. After completing the transformation experiment involving the coding sequence of enzyme a-galactosidase, the recombinant colonies should

  1. Give blue color
  2. Not give blue color
  3. Have active α-galactosidase
  4. Both (2) and (3)

Answer. 2. Not give blue color

Question 23. Which of the following has the ability to transform normal cells into cancerous cells in animals?

  1. Agrobacterium tumifaciens
  2. Retroviruses
  3. DNA viruses
  4. Plasmids

Answer. 2. Retroviruses

Question 24. Which of the following is not applicable to Agrobacterium tumifaciens?

  1. Pathogen of several dicot plants.
  2. Has the ability to transform normal plant cells.
  3. Delivers gene of our interest.
  4. Ti plasmid of it is always pathogenic to plants with out any exception.

Answer. 4. Ti plasmid of it is always pathogenic to plants with out any exception.

Question 25. Insertional inactivation is related to

  1. Microinjection
  2. Gene gun
  3. Gel electrophoresis
  4. Selection of recombinants

Answer. 4. Selection of recombinants

Question 26. For transformation with recombinant DNA, the bacterial cells must first be made competent, which means

  1. Should increase their metabolic reactions
  2. Should decrease their metabolic reactions
  3. Increase efficiency with which DNA enters the bacterium
  4. Ability to divide fast

Answer. 3. Increase efficiency with which DNA enters the bacterium

Question 27. Which of the following method can be used for making the bacterial cell competent?

  1. Treating with specific concentration of divalent cation (Ca2+).
  2. Treating with specific concentration of monovalent cation (K).
  3. Heat shock.
  4. Both (1) and (3).

Answer. 4. Both (1) and (3).

Question 28. Which of the following techniques can be used to introduce foreign DNA into cell?

  1. Using disarmed pathogen
  2. Microinjection
  3. Gene gun
  4. All of these

Answer. 4. All of these

Question 29. During heat shock, the temperature used for giving thermal shock to the bacterium is

  1. 82°C
  2. 100°C
  3. Liquid nitrogen
  4. 42°C

Answer. 4. 42°C

Question 30. Which of the following enzymes is used in case of fungus to cause the release of DNA along with other macromolecules?

  1. Lysozyme
  2. Cellulase
  3. Chitinase
  4. Amylase

Answer. 3. Chitinase

Question 31. During the isolation of DNA, the addition of which of the following causes the precipitation of purified DNA?

  1. Chilled ethanol
  2. Ribonuclease enzyme
  3. DNA polymerase
  4. Proteases

Answer. 1. Chilled ethanol

Question 32. Which of the following is the correct sequence of PCR (polymerase chain reaction)?

  1. Denaturation → Annealing → Extension
  2. Extension → Denaturation → Annealing
  3. Annealing → Extension → Denaturation
  4. Denaturation → Extension → Annealing

Answer. 1. Denaturation → Annealing → Extension

Question 33. The most commonly used bioreactor is of stirring type. The stirrer facilitates

  1. Temperature control
  2. pH control
  3. Oxygen availability
  4. Product removal

Answer. 3. Oxygen availability

Question 34. After the completion of biosynthetic stage, the separation and purification of product is called

  1. Upstream processing
  2. Downstream processing
  3. Modern biotechnology
  4. Gene amplification

Answer. 2. Downstream processing

Question 35. From isolated DNA from a cell culture with seven de- sired genes, DNA segment can be excised by molecular scissors or chemical scalpels what biotechnologists call as

  1. Polymerase enzymes
  2. DNA ligase
  3. Restriction enzymes
  4. Helicase

Answer. 3. Restriction enzymes

Question 36. All the following statements about Stanley Cohen and Herbert Boyer are correct but one is wrong. Which one is wrong?

  1. They discovered recombinant DNA (rDNA) technology, and this marks the birth of modern biotechnology.
  2. They first produced healthy sheep clone, a Finn Dorset lamb, Dolly, from the differentiated adult mammary cells.
  3. They invented genetic engineering by combining a piece of foreign DNA containing a gene from a bacterium with a bacterial plasmid using the enzyme restriction endonuclease.
  4. They isolated the antibiotic resistance gene by cutting out a piece of DNA from the plasmid which was responsible for conferring antibiotic resistance.

Answer. 2. They first produced healthy sheep clone, a Finn Dorset lamb, Dolly, from the differentiated adult mammary cells.

Question 37. What is the fate of a piece of DNA which is somehow transferred into an alien organism?

  1. This piece of DNA would not be able to multiply itself in the progeny cells of the organism if not integrated into the genome of the organism.
  2. If the alien piece of DNA has become a part of the chromosome, it will replicate.
  3. If the alien piece of DNA is linked with the origin of replication in chromosome, it will replicate.
  4. All of these.

Answer. 4. All of these.

Question 38. In the year 1963, the two enzymes responsible for restricting the growth of bacteriophage in Escherichia coli were isolated. These were and, respectively.

  1. Ligase, restriction endonuclease
  2. Helicase, restriction endonuclease
  3. Methylase, restriction endonuclease
  4. DNA polymerase, restriction endonuclease

Answer. 3. Methylase, restriction endonuclease

Question 39. The cutting of DNA by restriction endonucleases results in fragments of DNA. These fragments are generally separated by a technique known as

  1. Gel-filtration chromatography
  2. Centrifugation
  3. Gel electrophoresis
  4. Thin-layer chromatography

Answer. 3. Gel electrophoresis

Question 40. Which of the following bacteria are known as natural genetic engineers of plants, as gene transfer is happening in nature without human interference?

  1. Azotobacter
  2. Agrobacterium tumefaciens
  3. Escherichia coli
  4. Rhizobium

Answer. 2. Agrobacterium tumefaciens

Question 41. The technique in which a foreign DNA is precipitated on the surface of tungsten or gold particles and shot into the target cells is known as

  1. Microinjection
  2. Chemical-mediated genetic transformation
  3. Electroporation
  4. Biolistics

Answer. 4. Biolistics

Question 42. The isolation of the genetic material in pure form-free from other macromolecules can be achieved by treating the bacterial cells/plant or animal tissues with the following enzymes, except

  1. Lysozyme
  2. Cellulase
  3. Chitinase
  4. Ligase

Answer. 4. Ligase

Question 43. Which of the following is not a recombinant protein used in medical practice?

  1. TPA (tissue plasminogen activator)
  2. Interferon (α, B, and 7)
  3. Vaccine (for hepatitis B)
  4. Heparin

Answer. 4. Heparin

Question 44. cDNA is

  1. Circular DNA in bacteria
  2. Complementary DNA
  3. Copy DNA
  4. Both (2) and (3)

Answer. 4. Both (2) and (3)

Question 45. The Noble Prize of 1978 for restriction endonuclease technology was given to

  1. Temin and Baltimore
  2. Milstein and Kohler
  3. Arber, Nathans, and Smith
  4. Holley, Khorana, and Nirenberg

Answer. 3. Arber, Nathans, and Smith

Question 46. Plasmids are used in genetic engineering because they

  1. Are easily available
  2. Are able to integrate with host chromosome
  3. Are able to replicate along with chromosomal DNA
  4. Contain DNA sequence coding for drug resistance

Answer. 3. Are able to replicate along with chromosomal DNA

Question 47. Which of the following processes and techniques are included under biotechnology?

A. In vitro fertilization leading to a test-tube baby.

B. Synthesizing gene and using it.

C. Developing DNA vaccine.

D. Correcting a defective gene.

  1. (B) and (D) only (3)
  2. (B), (C), and (D)
  3. (A) and (B)
  4. (A), (B), (C), and (D)

Answer. 4. (A), (B), (C), and (D)

Question 48. The tumor-inducing (Ti) plasmid has now been modified to a cloning vector which is no more pathogenic to plants but is still able to use mechanisms to deliver genes of our interest into a variety of plants because Ti plasmid has been modified by

  1. Adding tumor-forming genes
  2. Deleting tumor-forming genes
  3. Adding genes resistant to endonucleases
  4. Deleting endonuclease

Answer. 2. Deleting tumor-forming genes

Question 49. Which of the following statements is incorrect?

  1. Plasmids have the ability to replicate within the bacterial cells independent of the control of chromosomal DNA.
  2. Some plasmids have only one or two copies per cell whereas others may have 15-100 copies per cell.
  3. Bacteriophages have the ability to replicate within the bacterial cell independent of the control of chromosomal DNA.
  4. Transformation is a procedure of separation and isolation of DNA fragments.

Answer. 4. Transformation is a procedure of separation and isolation of DNA fragments.

Question 50. Which of the following is the first artificial cloning vector that has two selectable markers-tetracycline (tetR) and antibiotic restriction enzymes (ampR)?

  1. YAC
  2. BAC
  3. pBR322
  4. Cosmid vectors

Answer. 3. pBR322

Question 51. Restriction endonucleases are most widely used in recombinant DNA technology. They are obtained from

  1. Bacteriophage
  2. Bacterial cells
  3. Plasmids
  4. All prokaryotic cells

Answer. 2. Bacterial cells

Question 52. All the following statements are correct about genetic engineering, but one is wrong. Which one is wrong?

  1. It is a technique for artificially and deliberately modifying DNA (genes) to suit human needs.
  2. It is often referred as gene splicing.
  3. The organism carrying the foreign genes is termed as transgenic or GMO.
  4. Alec Jeffrey is the father of genetic engineering.

Answer. 4. Alec Jeffrey is the father of genetic engineering.

Question 53. All the following are the properties of enzyme Taq polymerase, except

  1. It is thermostable DNA polymerase
  2. It is isolated from a bacterium, Thermus aquaticus
  3. It is used for the amplification of gene of interest using PCR
  4. It is thermostable RNA polymerase

Answer. 4. It is thermostable RNA polymerase

Question 54. Which of the following is incorrect match?

  1. Gene therapy: An abnormal gene is replaced by normal gene
  2. Cloning: Ability to multiply copies of antibiotic resistance gene in E. coli
  3. Restriction enzymes: Molecular scissors
  4. Exonucleases: Molecular glue

Answer. 4. Exonucleases: Molecular glue

Question 55. Appropriate techniques have been developed for large- scale cell culture using bioreactors for producing

  1. Foreign gene product
  2. Vaccines
  3. Hormones
  4. All of these

Answer. 4. All of these

Question 56. The uptake of genes by cells in microbes and plants is termed as

  1. Insertional inactivation
  2. Transformation
  3. Selectable markers
  4. Cloning vectors

Answer. 2. Transformation

Question 57. If we ligate a foreign DNA at the BamHI site of tetracycline resistance gene in pBR322, the recombinant plasmid will

  1. Show ampicillin resistance only
  2. Show tetracycline resistance
  3. Will grow well on tetracycline-containing medium
  4. Will not grow on ampicillin-containing medium

Answer. 1. Show ampicillin resistance only

Question 58. Polyethylene glycol can help in the uptake of foreign DNA into the host cell. This type of gene transfer is called

  1. Electroporation
  2. Chemical mediated genetic transformation
  3. Microinjection
  4. Particle gun

Answer. 2. Chemical mediated genetic transformation

Question 59. The normal E. coli cells carry resistance against which of the following antibiotics?

  1. Ampicillin
  2. Chloramphenicol
  3. Tetracycline or kanamycin
  4. None of these

Answer. 4. None of these

Question 60. The isolation of genetic material from fungal cells does not involve the use of

  1. Agarose
  2. Chitinase
  3. Ethanol
  4. Water

Answer. 1. Agarose

Question 61. In a restriction digestion experiment, the sticky ends of vector rejoined forming a circular vector without insert. Which enzyme can be used to eliminate this possibility?

  1. DNA ligase
  2. Alkaline phosphatase
  3. DNA polymerase
  4. RNA polymerase

Answer. 2. Alkaline phosphatase

Question 62. Denaturation can be achieved at which temperature during PCR?

  1. 72°C
  2. 95°C
  3. 40°C
  4. 25°C

Answer. 2. 95°C

Question 63. Choose the incorrect statement with respect to Agrobacterium tumefaciens.

  1. It is a Gram-negative soil bacterium.
  2. It produces crown gall disease in dicot plants.
  3. The foreign DNA is inserted at the ori site of Ti plasmid.
  4. Ti plasmid becomes incorporated into the plant chromosomal DNA.

Answer. 3. The foreign DNA is inserted at the ori site of Ti plasmid.

Question 64. Which is not a method for the introduction of recombinant DNA into host cells?

  1. Electroporation
  2. Biolistics
  3. Transfection
  4. Restriction digestion

Answer. 4. Restriction digestion

Question 65. The essential requirements for a gene amplification reaction are

  1. 20 mg of DNA template
  2. Forward and reverse primers
  3. Mg2+
  4. All of these

Answer. 4. All of these

Question 66. Choose the incorrect statement with respect to PCR reaction:

  1. It requires Taq polymerase.
  2. It requires dNTP’s.
  3. It generates 2n molecules after n number of cycles.
  4. The optimum temperature for polymerization step is greater than or equal to 90°C.

Answer. 4. The optimum temperature for polymerization step is greater than or equal to 90°C.

Question 67. Which is not an application of PCR?

  1. DNA fingerprinting
  2. DNA foot-printing
  3. Detection of mutation
  4. Prenatal diagnosis

Answer. 2. DNA foot-printing

Question 68. Rejoining of vector molecule after restriction enzyme digestion can be avoided by

  1. Using different enzymes for insert and vector
  2. Using same enzyme for insert and vector
  3. Using DNA ligase immediately after digestion
  4. Using alkaline phosphatase on only vector

Answer. 4. Using alkaline phosphatase on only vector

Question 69. If the target gene is inserted at Sal 1 site of the recombinant, plasmid will show resistance for pBR322

  1. Ampicillin
  2. Tetracyline
  3. Both (1) and (2)
  4. Kanamycin

Answer. 1. Ampicillin

Question 70. It is theoretically possible for a gene from any organism to function in any other organism. Why is this possible?

  1. All organisms have ribosomes.
  2. All organisms have the same genetic code.
  3. All organisms are made up of cells.
  4. All organisms have similar nuclei.

Answer. 2. All organisms have the same genetic code.

Question 71. If you discovered a bacterial cell that contained no restriction enzymes, which of the following would you except to happen?

  1. The cell would create incomplete plasmids.
  2. The cell would be unable to replicate its DNA.
  3. The cell would become an obligate parasite.
  4. The cell would be easily infected by bacteriophages.

Answer. 4. The cell would be easily infected by bacteriophages.

Question 72. Assume that you are trying to insert a gene into a plasmid and someone gives you a preparation of DNA cut with restriction enzyme X. The gene you wish to insert has sites on both ends for cutting by restriction enzyme Y. You have a plasmid with a single site for Y, but not for X. Your strategy should be to

  1. Cut the plasmid with restriction enzyme X and insert the fragments cut with Y into the plasmid
  2. Cut the plasmid with restriction enzyme X and insert the gene into the plasmid
  3. Cut the plasmid twice with restriction enzyme Y and ligate the two fragments into the plasmid cut with the same enzyme
  4. Cut the plasmid twice with restriction enzyme Y and ligate the two fragments onto the ends of the human DNA fragments cut with restriction enzyme X

Answer. 3. Cut the plasmid twice with restriction enzyme Y and ligate the two fragments into the plasmid cut with the same enzyme

Question 73. 1. Transform bacteria with recombinant DNA molecule.

2. Cut the plasmid DNA using restriction enzymes.

3. Extract plasmid DNA from bacterial cells.

4. Hydrogen-bond the plasmid DNA to non-plasmid DNA fragments.

5. Use ligase to seal plasmid DNA to non-plasmid DNA.

From the given list, which of the following is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium?

  1. 4, 5, 1, 2, 3
  2. 3, 2, 4, 5, 1
  3. 3, 4, 5, 1, 2
  4. 2, 3, 5, 4, 1

Answer. 2. 3, 2, 4, 5, 1

Question 74. A eukaryotic gene has sticky ends produced by restriction endonuclease Eco RI. The gene is added to a mixture containing Eco RI and a bacterial plasmid that carries two genes, which make it resistant to ampicillin and tetracyline. The plasmid has one recognition site for Eco RI located in the tetracycline resistance gene. This mixture is incubated for several hours and then added to bacteria growing in nutrient broth. The bacteria are allowed to grow overnight and are streaked on a plate using a technique which produces isolated colonies that are clones of the original. Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient broth plus ampicillin and tetracycline, and nutrient broth containing no antibiotics.

The bacteria containing the engineered plasmid would grow in

  1. The ampicillin and tetracycline broth only
  2. The nutrient broth, the ampicillin broth, and the tetracycline broth
  3. The nutrient broth and the ampicillin broth only
  4. The nutrient broth only

Answer. 3. The nutrient broth and the ampicillin broth only

Question 75. Agrobacterium tumefaciens is used in genetic engineering for

  1. DNA mapping
  2. DNA modification
  3. Vector
  4. DNA fingerprinting

Answer. 3. Vector

Question 76. A genetically engineered bacteria used for clearing oil spills is

  1. Escherischia coli
  2. Bacillus subtilis
  3. Agrobacterium tumefaciens
  4. Pseudomonas putida

Answer. 4. Pseudomonas putida

Question 77. Who isolated the first restriction endonucleases?

  1. Temin and Baltimore
  2. Sanger
  3. Nathans and Smith
  4. Paul Berg

Answer. 3. Nathans and Smith

Question 78. Genetic engineering is

  1. Study of extra-nuclear gene
  2. Manipulation of genes by artificial method
  3. Manipulation of RNA
  4. Manipulation of enzymes

Answer. 2. Manipulation of genes by artificial method

Question 79. Which of the following enzymes cut the DNA molecule at specific nucleotide sequence?

  1. Restriction endonuclease
  2. DNA ligase
  3. RNA polymerase
  4. Exonuclease

Answer. 1. Restriction endonuclease

Question 80. DNA fingerprinting was invented by

  1. Karl Mullis
  2. Alec Jeffery
  3. Dr. Paul Berg
  4. Francis Collins

Answer. 2. Alec Jeffery

Question 81. Which structure is involved in genetic engineering?

  1. Plastid
  2. Plasmid
  3. Codon
  4. None

Answer. 2. Plasmid

Question 82. Which of the following is the example of chemical scissors?

  1. Eco RI
  2. HindIII
  3. Bam I
  4. All of the above

Answer. 4. All of the above

Question 83. Restriction endonucleases are used in genetic engineering because

  1. They can degrade harmful proteins
  2. They can join DNA fragments
  3. They can cut DNA at variable sites
  4. They can cut DNA at specific base sequences

Answer. 4. They can cut DNA at specific base sequences

Question 84. Chimeric DNA is

  1. DNA which contains uracil
  2. DNA synthesized from RNA
  3. Recombinant DNA
  4. DNA which contains single strand

Answer. 3. Recombinant DNA

Question 85. A piece of nucleic acid used to find out a gene by forming hybrid with it is called

  1. cDNA
  2. DNA probe
  3. Sticky end
  4. Blunt end

Answer. 2. DNA probe

Question 86. Which of the following is the example of direct gene transfer?

  1. Microinjection
  2. Electroporation
  3. Particle gun
  4. All the above

Answer. 4. All the above

Question 87. How many copies of DNA sample are produced in PCR technique after 6 cycles?

  1. 4
  2. 32
  3. 16
  4. 64

Answer. 3. 16

Question 88. The basic procedure involved in the synthesis of recombinant DNA molecule is depicted. The mistake in the cedure is procedure is

NEET Biology Bio-Technology Principles And Process Question 89

  1. Enzyme polymerase is not included
  2. The mammalian DNA is shown double stranded
  3. Only one fragment is inserted
  4. Two different restriction enzymes are used

Answer. 4. Two different restriction enzymes are used

Question 89. Western blotting is used for the identification of

  1. DNA
  2. RNA
  3. Protein
  4. All the above

Answer. 3. Protein

Question 90. In rDNA technique, which of the following technique is not used in introducing DNA into host cell?

  1. Transduction
  2. Conjugation
  3. Transformation
  4. Electroporation

Answer. 2. Conjugation

Question 91. Which of the following techniques are used in analyzing restriction fragment length polymorphism (RFLP)?

(a) Electrophoresis

(b) Electroporation

(c) Methylation

(d) Restriction digestion

  1. (a) and (c)
  2. (c) and (d)
  3. (a) and (d)
  4. (b) and (d)

Answer. 3. (a) and (d)

Question 92. Restriction enzymes are

  1. Not always required in genetic engineering
  2. Essential tool in genetic engineering
  3. Nucleases that cleave DNA at specific sites
  4. (2) and (3) both

Answer. 4. (2) and (3) both

Question 93. The function of restriction endonuclease enzyme is

  1. It is useful in genetic engineering
  2. It protects the bacterial DNA against foreign DNA
  3. It is helpful in transcription
  4. It is helpful in protein synthesis

Answer. 2. It protects the bacterial DNA against foreign DNA

Question 94. A bacterium modifies its DNA by adding methyl groups to the DNA. It does so to

  1. Clone its DNA
  2. Be able to transcribe many genes simultaneously
  3. Turn its gene on
  4. Protect its DNA from its own restriction enzyme

Answer. 4. Protect its DNA from its own restriction enzyme

Question 95. Plasmid has been used as vector because

  1. It is circular DNA which has capacity to join eukaryotic DNA
  2. It can move between prokaryotic and eukaryotic cells
  3. Both ends show replication
  4. It has antibiotic resistance gene

Answer. 1. It is circular DNA which has capacity to join eukaryotic DNA

Question 96. Which of the following cuts the DNA from specific places?

  1. Restriction endonuclease (Eco RI)
  2. Ligase
  3. Exonuclease
  4. Alkaline phosphate

Answer. 1. Restriction endonuclease (Eco RI)

Question 97. The manipulation of DNA in genetic engineering becomes possible due to the discovery of

  1. Restriction endonuclease
  2. DNA ligase
  3. Transcriptase
  4. Primase

Answer. 1. Restriction endonuclease

Question 98. Restriction enzymes

  1. Are endonucleases which cleave DNA at specific sites
  2. Make DNA complementary to an existing DNA or RNA
  3. Cut or join DNA fragments
  4. Are required in vector-less direct gene transfer

Answer. 1. Are endonucleases which cleave DNA at specific sites

Question 99. DNA fingerprinting refers to

  1. Techniques used for the identification of fingerprints of individuals
  2. Molecular analysis of profiles of DNA samples
  3. Analysis of DNA samples using imprinting devices
  4. Techniques used for molecular analysis of different specimens of DNA

Answer. 2. Molecular analysis of profiles of DNA samples

Question 100. Restriction endonucleases

  1. Are synthesized by bacteria as part of their defense compound
  2. Are present in mammalian cells for degradation of DNA when the cell dies
  3. Are used in genetic engineering for ligating two DNA molecules
  4. Are used for in vitro DNA synthesis

Answer. 1. Are synthesized by bacteria as part of their defense compound

Question 101. What is the first step in the Southern blot technique?

  1. Denaturation of DNA on the gel for hybridization with specific probe.
  2. Production of a group of genetically identical cells.
  3. Digestion of DNA by restriction enzyme.
  4. Isolation of DNA from a nucleated cell such as the one from the scene of crime.

Answer. 1. Denaturation of DNA on the gel for hybridization with specific probe.

Question 102. Which of the following is not produced by E. coli in lactose?

  1. B-galactosidase
  2. Thiogalactoside transacetylase
  3. Lactose dehydrogenase
  4. Lactose permease

Answer. 3. Lactose dehydrogenase

Question 103. The technique of transferring DNA fragment separated on agarose gel to a synthetic membrane such as nitrocellulose is known as

  1. Northern blotting
  2. Southern blotting
  3. Western blotting
  4. Dot blotting

Answer. 2. Southern blotting

Question 104. The production of a human protein in bacteria in genetic engineering is possible because

  1. Bacterial cell can carry out RNA splicing reactions
  2. The mechanism of gene regulation is identical in humans and bacteria
  3. Human chromosome can replicate in bacterial cell
  4. Genetic code is universal

Answer. 4. Genetic code is universal

Question 105. Electroporation procedure involves

  1. Fast passage of food through sieve pores in phloem elements with the help of electric stimulation
  2. Opening of stomatal pores during night by artificial light
  3. Making transient pores in the cell membrane to introduce gene constructs
  4. Purification of saline water with the help of a membrane system

Answer. 3. Making transient pores in the cell membrane to introduce gene constructs

Question 106. The total number of nitrogenous bases in human genome is estimated to be about

  1. 3.5 million
  2. 35 thousand
  3. 35 million
  4. 3.1 billion

Answer. 4. 3.1 billion

Question 107. Two microbes found to be very useful in genetic engineering are

  1. Escherichia coli and Agrobacterium tumefaciens
  2. Vibro cholerae and a tailed bacteriophage
  3. Diplococcus sp. and Pseudomonas sp.
  4. Crown gall bacterium and Caenorhabdits elegans

Answer. 1. Escherichia coli and Agrobacterium tumefaciens

Question 108. Restriction endonuclease

  1. Cuts the DNA molecule randomly
  2. Cuts the DNA molecule at specific sites
  3. Restricts the synthesis of DNA inside the nucleus
  4. Synthesizes DNA

Answer. 2. Cuts the DNA molecule at specific sites

Question 109. The restriction enzyme Eco RI has the property of

  1. Endonuclease activity
  2. Exonuclease activity
  3. Ligation activity
  4. Correcting the topology of replicating DNA

Answer. 1. Endonuclease activity

Question 110. DNA ligase is an enzyme that catalyzes the

  1. Splitting of DNA threads into small bits
  2. Joining of the fragments of DNA
  3. Denaturation of DNA
  4. Synthesis of DNA

Answer. 2. Joining of the fragments of DNA

Question 111. More advancement in genetic engineering is due to

  1. Restriction endonuclease
  2. Reverse transcriptase
  3. Protease
  4. Zymase

Answer. 1. Restriction endonuclease

Question 112. The function of PCR is

  1. Translation
  2. Transcription
  3. DNA amplification
  4. None of these

Answer. 3. DNA amplification

Question 113. Which of the following is used as the best genetic vector?

  1. Bacillus thuriengenesis
  2. Agrobacterium tumefaciens
  3. Pseudomonas putida
  4. All of these

Answer. 2. Agrobacterium tumefaciens

Question 114. The transfer of protein from electrophoretic gel to nitrocellulose membrane is known as

  1. Transferase
  2. Northern blotting
  3. Western blotting
  4. Southern blotting

Answer. 3. Western blotting

Question 115. DNA fingerprinting was first discovered by

  1. Alec Jeffery
  2. Cark Mullis
  3. C. Milstein
  4. Dr. Paul Berg

Answer. 1. Alec Jeffery

Question 116. Which of the following enzyme is used to join DNA fragments?

  1. Terminase
  2. Endonuclease
  3. Ligase
  4. DNA polymerase

Answer. 3. Ligase

Question 117. Restriction endonucleases are enzymes which

  1. Make cuts at specific positions within the DNA molecule
  2. Recognize a specific nucleotide sequence for binding of DNA ligase
  3. Restrict the action of enzyme DNA polymerase
  4. Remove nucleotides from the ends of the DNA molecule

Answer. 1. Make cuts at specific positions within the DNA molecule

Question 118. Satellite DNA is a useful tool in

  1. Organ transplantation
  2. Sex determination
  3. Forensic science
  4. Genetic engineering

Answer. 3. Forensic science

Question 119. PCR and restriction fragment length polymorphism are the methods for

  1. Genetic transformation
  2. DNA sequencing
  3. Genetic fingerprinting
  4. Study of enzymes

Answer. 3. Genetic fingerprinting

Question 120. Which one is a true statement regarding DNA polymerase used in PCR?

  1. It serves as a selectable marker.
  2. It is isolated from a virus.
  3. It remains active at high temperature.
  4. It is used to ligate introduced DNA in recipient cells.

Answer. 3. It remains active at high temperature.

Question 121. For transformation, microparticles coated with DNA to be bombarded with gene gun are made up of

  1. Platinum or zinc
  2. Silicon or platinum
  3. Gold or tungsten
  4. Silver or platinum

Answer. 3. Gold or tungsten

Question 122. A single strand of nucleic acid tagged with a radioactive molecule is called

  1. Selectable marker
  2. Plasmid
  3. Probe
  4. Vector

Answer. 3. Probe

Question 123. The following figure is the diagrammatic representation of the E. coli vector PBR 322. Which one of the given options correctly identifies its certain component(s)? 

  1. rop-reduced osmotic pressure
  2. Hind III, Eco RI-selectable markers
  3. ampR, tetR-antibiotic resistance genes
  4. ori-original restriction enzyme

Answer. 3. ampR, tetR-antibiotic resistance genes

NEET Biology Bio-Technology Principles And Process Question 29

Question 124. Which one of the following is a case of wrong matching?

  1. Vector DNA: Site for tRNA synthesis
  2. Micropropagation: In vitro production of plants in large numbers
  3. Callus: Unorganized mass of cells produced in tissue culture
  4. Somatic hybridization: Fusion of two diverse cells

Answer. 1. Vector DNA: Site for tRNA synthesis

Question 125. Biolistics (gene gun) is suitable for

  1. Disarming pathogen vectors
  2. Transformation of plant cells
  3. Constructing recombinant DNA by joining with vectors
  4. DNA fingerprinting

Answer. 3. Constructing recombinant DNA by joining with vectors

Question 126. In genetic engineering, the antibiotics are used

  1. As selectable markers
  2. To select healthy vectors
  3. As sequences from where replication starts
  4. To keep the cultures free of infection

Answer. 1. As selectable markers

Question 127. What is it that forms the basis of DNA fingerprinting?

  1. The relative proportions of purines and pyrimidines in DNA.
  2. The relative difference in the DNA occurrence in blood, skin, and saliva.
  3. The relative amount of DNA in the ridges and grooves of fingerprints.
  4. Satellite DNA occurring as highly repeated short DNA segments.

Answer. 4. Satellite DNA occurring as highly repeated short DNA segments.

Question 128. The following figure shows three steps (A)-(C) of PCR. Select the option giving correct identification together with what it represents?

NEET Biology Bio-Technology Principles And Process Question 34

Options:

  1. B-Denaturation at a temperature of about 98°C separating the two DNA strands
  2. A-Denaturation at a temperature of about 50°C
  3. C-Extension in the presence of heat stable DNA polymerase
  4. A-Annealing with two sets of primers

Answer. 3. C-Extension in the presence of heat stable DNA polymerase

Question 129. Which one of the following represents a palindromic sequence in DNA?

  1. 5′-GAATTC-3′; 3′- CTTAAG-5′
  2. 5′-CCATCC-3′; 3′-GAATCC-5′
  3. 5′-CATTAG-3′; 3′-GATAAC-5′
  4. 5′-GATACC-3′; 3′-CCTAAG-5′

Answer. 1. 5′-GAATTC-3′; 3′- CTTAAG-5′

Question 130. DNA fragments generated by restriction endonucleases in a chemical reaction can be separated by

  1. Polymerase chain reaction
  2. Electrophoresis
  3. Restriction mapping
  4. Centrifugation

Answer. 2. Electrophoresis

Question 131. The colonies of recombinant bacteria appear white in contrast to the blue colonies of non-recombinant bacteria because of

  1. Insertional inactivation of alpha-galactosidase in non-recombinant bacteria
  2. Insertional inactivation of alpha-galactosidase in recombinant bacteria
  3. Inactivation of glycosidase enzyme in recombinant bacteria
  4. Non-recombinant bacteria containing beta-galactosidase

Answer. 4. Non-recombinant bacteria containing beta-galactosidase

Assertion-Reasoning Questions

In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R).

  1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark (1).
  2. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
  3. If Assertion is true but Reason is false, then mark (3).
  4. If both Assertion and Reason are false, then mark (4).

Question 1. Assertion: DNA ligase plays important role in recombinant DNA technology.

Reason: The linking of antibiotic resistance gene with plasmid vector became possible by enzyme DNA ligase.

Answer. 1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark(1).

Question 2. Assertion: Restriction enzymes belong to a larger class of enzymes called nucleases.

Reason: Each restriction enzyme recognizes a specific palindromic nucleotide sequence in the DNA.

Answer. 2. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark (2).

Question 3. Assertion: During gel electrophoresis, DNA fragments move towards the anode.

Reason: DNA fragments are negatively charged molecules.

Answer. 1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark(1).

Question 4. Assertion: The selection of recombinants due to inacti- vation of antibiotics is a cumbersome procedure.

Reason: It requires simultaneous plating on two plates having different antibiotics.

Answer. 1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark(1).

Question 5. Assertion: Taq polymerase is involved in PCR technique.

Reason: This enzyme remains active during high temperature including denaturation of double-stranded DNA.

Answer. 1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark(1).

Question 6. Assertion: Small DNA fragments will arrange towards the positive end after gel electrophoresis in DNA test.

Reason: DNA is negatively charged.

Answer. 1. If both Assertion and Reason are true and the reason is the correct explanation of the assertion, then mark(1).

Question 7. Assertion: PCR technique is used in the amplification of a specific gene.

Reason: In PCR technique, Taq polymerase enzyme is used, and this enzyme is thermosensitive.

Answer. 3. If Assertion is true but Reason is false, then mark (3).