NEET Biology Notes – Bio Technology And Its Applications

BioTechnology And Its Applications

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.

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.

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• 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.

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

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.

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.

• 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.

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.

• 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

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.

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.)

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.

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.

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.

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.

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.

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.

Choose the correct answer:

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

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

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

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:

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

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).