UP Board Class 9 Science Chapter 5 The Fundamental Unit Of Life Multiple Choice Questions

The Fundamental Unit Of Life Multiple Choice Questions

Question 1. The word ‘cell’ is derived from

1. The Greek word that means ‘small box-like structure’
2. The Latin word that means a little room’
3. The Greek word that means a little room’
4. The Latin word that means ‘small box-like structure’

Answer: 2. The Latin word that means a little room’

Robert Hooke in 1665, while examining a thin slice of cork, discovered dead cells. He used the word’ cell, which is derived from Latin, and means a little room’ to describe these units of cork slice.

Question 2. Choose the incorrect statement from the following options.

1. All cells arise from pre-existing cells only
2. Rudolf Virchow proposed the cell theory
3. The nucleus was discovered by Robert Brown in 1831
4. The nucleus and cytoplasm of a living cell, all together form the protoplasm

Answer: 3. Nucleus was discovered by Robert Brown in 1831

• The nucleus was discovered by Robert Brown in 1831. The cell theory was proposed by
  Schleiden and Schwann in 1839, postulated that all living beings are composed of cells and their products.
• In 1855, Rudolf Virchow modified the cell theory with his postulate, ‘Omnis cellula-e-cellula, which means, a new cell is derived from a pre-existing cell only.

Question 3. Every living animal cell is enclosed by an outermost thin and delicate covering that separates the contents of the cell from the external environment, is primarily composed of

1. Glycolipids
2. Glycoproteins
3. Lipids
4. Phospholipids

Answer: 4. Phospholipids

• The outermost thin and delicate covering of animal cells that separates the contents of a cell from the external environment is called the plasma membrane or cell membrane.
• The chemical analysis of the plasma membrane revealed that it is primarily composed of phospholipids. While the remaining minor fraction is constituted by proteins embedded in the phospholipid layer, polysaccharides glycolipids, etc.

Question 4. While preparing a temporary mount of onion peel, the peel taken from the onion bulb is placed immediately into the Petri dish containing water, because

1. It is an experimental procedure
2. It brings out plasmolysis due to osmosis of water into the cell
3. It prevents the peel from getting folded and dehydrated
4. It removes the impurities from the peel

Answer: 3. It prevents the peel from getting folded and dehydrated

While preparing a temporary mount of plant cells or animal cells, the specimen collected is immediately placed into the Petri dish/watch glass containing water, to prevent the cells from dehydrating and the peel from getting folded.

Question 5. Which one of the following terms describes a nucleus without a nuclear membrane?

1. Nucleolus
2. Primitive nucleus
3. Nucleoid
4. All of these

Answer: 3. Nucleoid

The primitive type of undeveloped nucleus which lacks a nuclear membrane is called nucleoid. A nucleoid is found in prokaryotic cells, for example., bacteria.

Question 6. Which one of the following cellular functions is performed by the endoplasmic reticulum?

1. Production of hydrolytic enzymes
2. Supply of energy to the cell
3. Formation of lysosomes
4. Production of vacuoles

Answer: 1. Production of hydrolytic enzymes

The digestive or hydrolytic enzymes (proteins) are produced by the rough endoplasmic reticulum for the synthesis of lysosomes.

Question 7. The function of biosynthesis of the plasma membrane and metabolism of toxic or poisonous substances is carried out by

1. Rough endoplasmic reticulum
2. Golgi apparatus
3. Smooth endoplasmic reticulum
4. Both (1) and (3)

Answer: 3. Smooth endoplasmic reticulum

Smooth endoplasmic reticulum is involved in the detoxification of drugs, insecticides, etc., inside a cell. It also carries out the biogenesis of plasma membranes and various steroid hormones.

Question 8. Which one of the following is not a functional role of the plasma membrane?

1. It forms the microvilli in the intestines of human beings
2. It maintains the cellular homeostasis
3. It protects the cell from plasmolysis
4. It projects small finger-like projects called pseudopodia for endocytosis

Answer: 3. It protects the cell from plasmolysis

Plasmolysis is the phenomenon of contraction or shrinkage of protoplasm in a plant cell, away from the cell wall, due to exosmosis of water, when the cell is placed in a hypertonic solution.

The plasma membrane cannot restrict the osmosis of water, thus it cannot protect cells from plasmolysis.

Question 9. Choose the incorrect statement in context with the cell.

1. A cell can replicate independently to produce daughter cells
2. They can perform all the metabolic activities of an individual
3. Every organism starts its life as a single-cell
4. Mycoplasma is the smallest cell but is larger than bacterial cell

Answer: 4. Mycoplasma is the smallest cell, but is larger than bacterial cell

Mycoplasma (PPLO) is the smallest cell, which is smaller than bacteria, but larger than viruses.

Question 10. Select the correct functional role of the vacuole in a cell.

1. Vacuoles do not help in maintaining the rigidity of the cell
2. Vacuoles form thread-like tails in sperms of many mammals
3. Vacuoles expel excess water and waste products from the cell
4. Vacuoles store only excretory products of a cell

Answer: 3. Vacuoles expel excess water and waste products from the cell

In unicellular organisms, vacuoles carry out the role of expelling excess water and wastes from the cell. They also store food and water in cells and help maintain the rigidity of cells by controlling osmosis. Thus, they are also known as dustbins or storehouses of cells.

Question 11. Choose the incorrect statement

1. Lysosomes from the garbage disposal system of animal cells
2. Ribosome carries out the synthesis of proteins
3. Liquid content of the vacuole in a plant cell is called cell sap
4. The colorless plastid that stores proteins, lipids, and starch is named xanthophyll

Answer: 4. The colorless plastid that stores proteins, lipids, and starch is named xanthophyll

Leucoplast is a colorless plastid that stores proteins, lipids, and starch, while xanthophylls are yellow, red, or orange pigments of green plants.

Question 12. Who coined the term ‘protoplasm’?

1. Purkinje
2. Robert Brown
3. Virchow
4. Palate

Answer: 1. Purkinje

Question 13. The longest cell of the human body is

1. RBC
2. Nerve cell
3. Muscle cell
4. Sperm

Answer: 2. Nerve cell

Question 14. The outermost thin, living membrane that separates the contents of the cell from its external environment is called as

1. Slime layer
2. Cell wall
3. Cell membrane
4. Capsule

Answer: 3. Cell membrane

Question 15. Select the incorrect pair.

1. Powerhouse of cell—Mitochondria
2. Kitchen of cell—Chloroplast
3. Brain of cell—Ribosomes
4. Suicidal bag—Lysosomes

Answer: 3. Brain of cell—Ribosomes

Question 16. The example(s) of prokaryotic cells is/are

1. Blue-green algae
2. Fungi
3. Bacteria
4. Both (1) and (3)

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

Question 17. Name the scientist who discovered the Golgi apparatus.

1. Camillo Golgi
2. Robert Brown
3. Leeuwenhoek
4. None of these

Answer: 1. Camillo Golgi

Question 18. Which of the following is/are semi-autonomous organelle(s)?

1. Nucleus
2. Mitochondria
3. Chloroplast
4. Both (2) and (3)

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

Question 19. Which one of the following is known as the energy currency of the cell?

1. ATP
2. GTP
3. FTP
4. None of these

Answer: 1. ATP

Question 20. Oil or fat-storing plastids are called as

1. Elaioplast
2. Amyloplast
3. Aleuroplast
4. Tonoplast

Answer: 1. Elaioplast

Question 21. The function(s) of vacuoles is/are

1. To provide turgidity or rigidity to plant cell
2. Storage of food material
3. To expel excess of water
4. All of the above

Answer: 4. All of the above