9th class Biology, Chapter 6: Biomolecules MCQs

1. What is the primary function of carbohydrates?

1. (A) Provide energy ✓
2. (B) Act as enzymes
3. (C) Regulate processes
4. (D) Make membranes

2. How will you differentiate between monosaccharides and polysaccharides?

1. (A) Monosaccharides are single sugars. ✓
2. (B) Polysaccharides are sweet in taste.
3. (C) Monosaccharides are present in plant cell wall.
4. (D) Polysaccharides dissolve easily.

3. What is true about cellulose?

1. (A) It is sweet in taste.
2. (B) It is digestible by human digestive system.
3. (C) It provides structural support in plants. ✓
4. (D) It is soluble in water.

4. Which of the following proteins is involved in oxygen transport?

1. (A) Insulin
2. (B) Haemoglobin ✓
3. (C) Collagen
4. (D) Keratin

5. Which component of an amino acid determines its unique properties?

1. (A) Amino group
2. (B) Carboxyl group
3. (C) R group (side group) ✓
4. (D) Hydrogen group

6. Which proteins are involved in defence against pathogens?

1. (A) Antibodies ✓
2. (B) Myosin
3. (C) Fibrinogen
4. (D) Haemoglobin

7. Which of the following are the units of most lipids?

1. (A) Amino acids
2. (B) Fatty acids and glycerol ✓
3. (C) Nucleotides
4. (D) Simple sugars

8. How do unsaturated fatty acids differ from saturated fatty acids?

1. (A) They have more hydrogen atoms.
2. (B) They contain double bonds in their hydrocarbon chains. ✓
3. (C) They are solid at room temperature.
4. (D) They are found only in animal fats.

9. Which of the following is NOT a function of proteins?

1. (A) Transport oxygen in the blood.
2. (B) Carry genetic information. ✓
3. (C) Help in digesting food.
4. (D) Fight against pathogens.

10. Which components make up a nucleotide?

1. (A) Sugar, phosphate, nitrogenous base ✓
2. (B) Amino acid, sugar, nitrogenous base
3. (C) Fatty acid, phosphate, nitrogenous base
4. (D) Protein, sugar, nitrogenous base

11. Which nitrogenous base is found in RNA but not in DNA?

1. (A) Adenine
2. (B) Thymine
3. (C) Uracil ✓
4. (D) Guanine

12. The molecules produced by organisms are called:

1. (A) Inorganic compounds
2. (B) Minerals
3. (C) Biomolecules ✓
4. (D) Macroions

13. Biochemistry is the study of:

1. (A) The chemical processes within living organisms ✓
2. (B) Structure of animals
3. (C) Classification of plants
4. (D) Rocks and minerals

14. Which of the following is NOT a biomolecule?

1. (A) Nucleic acids
2. (B) Sodium chloride ✓
3. (C) Carbohydrates
4. (D) Lipids

15. Which biomolecule makes the largest part (50 %) of the dry mass of protoplasm?

1. (A) Nucleic acids
2. (B) Lipids
3. (C) Carbohydrates
4. (D) Proteins ✓

16. Biomolecules make what percentage of the dry mass of protoplasm?

1. (A) 50 %
2. (B) 75 %
3. (C) 93 % ✓
4. (D) 100 %

17. The type of metabolism in which simpler substances are combined to form complex substances is:

1. (A) Catabolism
2. (B) Anabolism ✓
3. (C) Digestion
4. (D) Excretion

18. In eukaryotic cells DNA is found in the nucleus, mitochondria and:

1. (A) Lysosomes
2. (B) Golgi apparatus
3. (C) Cell wall
4. (D) Chloroplasts ✓

19. The ratio of hydrogen to oxygen in carbohydrates is:

1. (A) 1:2
2. (B) 3:1
3. (C) 1:1
4. (D) 2:1 ✓

20. The general formula of carbohydrates is:

1. (A) Cn(H2O)n ✓
2. (B) CnH2n
3. (C) C2nHn
4. (D) CHO2