MCQs

1. At room temperature, which kind of fatty acid exists in solid form?
   a) Unsaturated b) Phosphorylated c) Modified d) Saturated
2. Which biomolecule is the chief constituent of the cell membrane?
   a) Proteins b) Carbohydrates c) Lipids d) DNA
3. The distinctive characteristics of each amino acid are decided by which part?
   a) Amino group b) Carboxyl group c) Hydrogen group d) R group (side chain)
4. Nucleic acids are built from which fundamental units?
   a) Amino acids b) Fatty acids c) Nucleotides d) Monosaccharides
5. In which of the following do lipids dissolve?
   a) Water b) Organic solvents like alcohol c) Glucose solution d) Saltwater
6. The double helix model of DNA was put forward by which scientists?
   a) Mendel and Darwin b) Watson and Crick c) Einstein and Newton d) Pasteur and Koch
7. Which statement about cellulose is correct?
   a) It provides structural support in plants b) It is sweet in taste c) It is digestible by the human digestive system d) It is soluble in water
8. In which parts of the cell are lipids mainly located?
   a) Nucleus and ribosomes b) Endoplasmic reticulum only c) Mitochondria only d) Cell membrane and cytoplasm
9. Which nitrogenous base is absent from RNA?
   a) Adenine b) Cytosine c) Thymine d) Uracil
10. Which of the following is not a role of proteins?
    a) Carry genetic information b) Transport oxygen in the blood c) Help in digesting food d) Fight against pathogens
11. Which of the following provides oils obtained from plants?
    a) Milk b) Meat c) Sunflower seeds d) Eggs
12. Which of these is used by the body for long-term energy storage?
    a) Proteins b) DNA c) Fats d) RNA
13. What distinguishes unsaturated fatty acids from saturated fatty acids?
    a) They are solid at room temperature b) They contain double bonds in their hydrocarbon chains c) They have more hydrogen atoms d) They are found only in animal fats
14. In DNA, adenine forms a pair with which nitrogenous base?
    a) Guanine b) Cytosine c) Uracil d) Thymine
15. How is metabolism defined?
    a) Process of breaking down DNA b) All chemical reactions in an organism c) Only digestion-related reactions d) The process of breathing
16. Which event takes place during translation?
    a) DNA is replicated b) Ribosomes read mRNA to form proteins c) RNA is copied from DNA d) Lipids are synthesized
17. What role does mRNA play in the cell?
    a) Transports amino acids b) Forms ribosomes c) Produces lipids d) Carries genetic code
18. A nucleotide consists of which three parts?
    a) Fatty acid, phosphate, nitrogenous base b) Amino acid, sugar, nitrogenous base c) Protein, sugar, nitrogenous base d) Sugar, phosphate, nitrogenous base
19. The branch of science dealing with chemical processes inside living things is known as:
    a) Biotechnology b) Biochemistry c) Cytology d) Genetics
20. Which protein is in charge of carrying oxygen in the blood?
    a) Collagen b) Haemoglobin c) Actin d) Fibrin
21. What takes place during catabolism?
    a) Energy is used to build molecules b) Proteins are synthesized c) DNA is copied d) Complex molecules are broken down, releasing energy
22. Which of these vitamins dissolves in fat?
    a) Vitamin B b) Vitamin C c) Vitamin D d) Vitamin B12
23. Which of the following proteins takes part in the transport of oxygen?
    a) Collagen b) Keratin c) Insulin d) Haemoglobin
24. Fungal cell walls contain which polysaccharide?
    a) Glycogen b) Chitin c) Starch d) Cellulose
25. In eukaryotic cells, where is DNA mainly present?
    a) Cytoplasm b) Ribosomes c) Nucleus d) Cell membrane
26. How would you define biochemistry?
    a) Study of physical processes b) Study of chemical processes within living organisms c) Study of plant structures d) Study of energy transfer in cells
27. Lactose is mainly present in which source?
    a) Fruits b) Milk and dairy products c) Cereal crops d) Honey
28. Which of the following is a rich source of protein?
    a) Sugar cane b) Olive oil c) Pulses d) Fruits
29. Which group does not belong to the structure of an amino acid?
    a) Amino group b) Carboxyl group c) Phosphate group d) Side group (R)
30. Which kind of metabolism constructs complex molecules from simpler ones?
    a) Catabolism b) Anabolism c) Respiration d) Photosynthesis
31. Which scientists discovered the double helical structure of DNA?
    a) Mendel b) Watson and Crick c) Darwin d) Pasteur
32. Which molecules serve as the monomers of nucleic acids?
    a) Amino acids b) Monosaccharides c) Nucleotides d) Fatty acids
33. Which formula represents carbohydrates in general?
    a) (CH₂O)ₙ b) (C₆H₁₂O₆)ₙ c) (CH₃O)ₙ d) (C₂H₅O)ₙ
34. Which molecules join together to form proteins?
    a) Fatty acids b) Amino acids c) Nucleotides d) Monosaccharides
35. Lipids generally dissolve in which solvent?
    a) Water b) Alcohol c) Saltwater d) Sugar solution
36. Which RNA delivers amino acids to the ribosomes during protein synthesis?
    a) rRNA b) mRNA c) DNA d) tRNA
37. How many hydrogen bonds are formed between cytosine and guanine in DNA?
    a) 1 b) 2 c) 3 d) 4
38. What is the main role of carbohydrates?
    a) Act as enzymes b) Provide energy c) Regulate processes d) Make membranes
39. Which nitrogenous base occurs in RNA but is missing in DNA?
    a) Thymine b) Adenine c) Guanine d) Uracil
40. Metabolism refers to which of the following?
    a) The breakdown of simple sugars b) The synthesis of lipids only c) The storage of energy d) All chemical reactions in an organism
41. What is the role of dietary fiber (cellulose)?
    a) Energy storage b) Maintains proper bowel movements c) Hormone synthesis d) Oxygen transport
42. Which biomolecule is mainly responsible for holding genetic information?
    a) Proteins b) Lipids c) DNA d) Carbohydrate
43. How many amino acids have to be obtained through the diet?
    a) 20 b) 11 c) 9 d) 51
44. Which of these is not classified as a biomolecule?
    a) Proteins b) Lipids c) Water d) DNA
45. Which protein gives structural strength to hair and nails?
    a) Collagen b) Keratin c) Hemoglobin d) Insulin
46. Which lipid is stored as a long-lasting energy reserve?
    a) Phospholipids b) Fats c) Glycerol d) Oils
47. Most proteins are made from how many different amino acids?
    a) 9 b) 11 c) 20 d) 170
48. Which protein carries oxygen through the blood?
    a) Insulin b) Keratin c) Hemoglobin d) Collagen
49. Which of the following is not counted among the common biomolecules?
    a) Carbohydrates b) Proteins c) Vitamins d) Nucleic acids
50. Which base is exclusive to RNA and absent in DNA?
    a) Adenine b) Uracil c) Thymine d) Cytosine
51. Which proteins help protect the body against pathogens?
    a) Haemoglobin b) Myosin c) Antibodies d) Fibrinogen
52. Which biomolecule makes up half of the dry mass of protoplasm?
    a) Nucleic acids b) Proteins c) Carbohydrates d) Lipids
53. Watson and Crick were awarded the Nobel Prize for the DNA structure in which year?
    a) 1953 b) 1962 c) 1970 d) 1945
54. Which of the following lipids stays solid at room temperature?
    a) Olive oil b) Coconut oil c) Butter d) Corn oil
55. Which metabolic process assembles complex molecules from simpler ones?
    a) Catabolism b) Photosynthesis c) Respiration d) Anabolism
56. Proteins are chiefly composed of what?
    a) Fatty acids b) Nucleotides c) Amino acids d) Monosaccharides
57. What are lipids mainly built from?
    a) Amino acids and glycerol b) Nucleotides and sugars c) Phosphate and ribose d) Glycerol and fatty acids
58. Muscle contraction depends on which protein?
    a) Hemoglobin b) Actin c) Keratin d) Fibrin
59. What do ribosomes do in the cell?
    a) Store energy b) Break down glucose c) Synthesize proteins d) Carry oxygen
60. Which type of RNA transfers genetic information from DNA to the ribosomes?
    a) tRNA b) rRNA c) mRNA d) snRNA
61. Which carbohydrate gives structure to plant cell walls?
    a) Starch b) Glycogen c) Cellulose d) Glucose
62. Which proteins serve as catalysts in biochemical reactions?
    a) Hormones b) Enzymes c) Antibodies d) Structural proteins
63. Which polysaccharide do animals use to store energy?
    a) Starch b) Glycogen c) Cellulose d) Chitin
64. What is the principal role of RNA in the cell?
    a) Carries genetic information for organism development b) Acts as an enzyme c) Carries genetic information from DNA to ribosomes for protein synthesis d) Provides structural support to the cell
65. Which two units combine to form the disaccharide sucrose?
    a) Two glucose molecules b) Glucose and fructose c) Glucose and galactose d) Fructose and maltose
66. Double bonds are present in the structure of which fatty acids?
    a) Saturated fatty acids b) Unsaturated fatty acids c) Phospholipids d) Steroids
67. Which biomolecule accounts for 18% of the dry mass of protoplasm?
    a) Carbohydrates b) Proteins c) Nucleic acids d) Lipids
68. Which class of carbohydrates consists of a single sugar unit?
    a) Disaccharides b) Polysaccharides c) Monosaccharides d) Oligosaccharides
69. Which molecule derived from lipids assists in making hormones?
    a) Glycerol b) Cholesterol c) Fatty acids d) Phospholipids
70. The process in which DNA nucleotides are copied to form mRNA is termed:
    a) Translation b) Replication c) Transcription d) Mutation
71. Which of these lipids belongs to the steroids?
    a) Phospholipid b) Cholesterol c) Glycogen d) Cellulose
72. In DNA, which base is the partner of adenine?
    a) Cytosine b) Guanine c) Thymine d) Uracil
73. Which biomolecule forms the largest part of the dry mass of cells?
    a) Carbohydrates b) Proteins c) Lipids d) Nucleic acids
74. Which biomolecule serves both as an energy source and for energy storage?
    a) Proteins b) Lipids c) Carbohydrates d) RNA
75. What does fibrin do in the body?
    a) Muscle contraction b) Enzyme catalysis c) Hormone regulation d) Blood clotting
76. Biomolecules together make up what percentage of the dry mass of protoplasm?
    a) 50% b) 93% c) 7% d) 15%
77. Which of the following is a hexose sugar?
    a) Ribose b) Deoxyribose c) Glucose d) Chitin
78. In nature, cellulose is obtained mainly from what?
    a) Animal muscles b) Plant cell walls c) Insect exoskeletons d) Fungal spores
79. Most lipids are made up of which units?
    a) Amino acids b) Nucleotides c) Simple sugars d) Fatty acids and glycerol
80. Which disaccharide is typically present in milk?
    a) Sucrose b) Maltose c) Fructose d) Lactose
81. What is the main focus of molecular biology?
    a) The structure and function of biomolecules b) The movement of organisms c) The reproduction of cells d) The photosynthesis process only
82. Which polysaccharide is referred to as animal starch?
    a) Cellulose b) Starch c) Glycogen d) Chitin
83. What is the chief role of carbohydrates in cells?
    a) Structural support b) Enzyme production c) Hormone synthesis d) Energy supply
84. What is the term for the breakdown of large molecules into smaller ones?
    a) Anabolism b) Metabolism c) Catabolism d) Synthesis
85. Which substance is the principal constituent of cell membranes?
    a) Fats b) Oils c) Phospholipids d) Cholesterol
86. Which statement correctly distinguishes monosaccharides from polysaccharides?
    a) Polysaccharides are sweet in taste b) Polysaccharides dissolve easily in water c) Monosaccharides are single sugars d) Monosaccharides are present in plant cell walls
87. Which of the following is a simple sugar (monosaccharide)?
    a) Sucrose b) Starch c) Glucose d) Cellulose
88. Which lipid forms a major part of cell membranes?
    a) Triglycerides b) Phospholipids c) Steroids d) Cholesterol
89. What is the chief function of carbohydrates in the body?
    a) Act as enzymes b) Regulate body processes c) Form cell membranes d) Provide energy
90. What is the process called in which mRNA is made from DNA?
    a) Translation b) Transcription c) Replication d) Mutation
91. The hard outer covering of crabs and lobsters contains which carbohydrate?
    a) Starch b) Glycogen c) Cellulose d) Chitin
92. How is a gene defined?
    a) A type of protein b) A type of lipid c) A sugar molecule d) A segment of DNA that codes for a protein
93. DNA nucleotides contain which sugar?
    a) Ribose b) Deoxyribose c) Glucose d) Fructose
94. RNA contains which sugar?
    a) Deoxyribose b) Glucose c) Ribose d) Fructose
95. Which protein is involved in the clotting of blood?
    a) Myosin b) Actin c) Fibrin d) Keratin

Short Questions

1. Differentiate between Fats and oils
2. What is the function of starch?
3. Differentiate between Biochemistry and molecular biology.
4. What are the three components of a nucleotide?
5. What is translation?
6. What is the function of DNA?
7. What is glycerol?
8. What would happen if the body could not break down glycogen?
9. What are nucleic acids?
10. What are the types of RNA? Write their functions.
11. What are biomolecules?
12. What is the primary function of carbohydrates?
13. Why are proteins considered the most abundant biomolecules in the cell?
14. What is the monomer of a protein?
15. How do proteins help in muscle contraction?
16. What is the role of lipids in insulation?
17. Differentiate between Glycogen and starch.
18. What is metabolism?
19. What are the sources of proteins?
20. Why are polysaccharides insoluble in water?
21. What is maltose made of?
22. What are the four nitrogenous bases in DNA?
23. Where is glycogen stored in animals?
24. What are the main functions of carbohydrates in the body?
25. What are lipids?
26. Why are carbohydrates also called saccharides?
27. How do lipids help in hormone synthesis?
28. What is the role of antibodies?
29. Why are lipids insoluble in water?
30. What is the difference between DNA and RNA?
31. Who discovered the double helix structure of DNA?
32. How does dietary fiber help the human body?
33. Why do athletes consume carbohydrate-rich foods before competitions?
34. What are polysaccharides?
35. Name one lipid that helps in the absorption of fat-soluble vitamins.
36. Define amino acid and draw its structure.
37. What is molecular biology?
38. Describe the structure of a DNA molecule.
39. What are the basic components of lipids? Draw their structures.
40. What is biochemistry?
41. What are monosaccharides? Give examples.
42. Name two sources of plant lipids.
43. What is transcription?
44. What are carbohydrates?
45. Differentiate between saturated and unsaturated fatty acids.
46. What are the two components of lipids?
47. What is chitin and where is it found?
48. What percentage of protoplasm’s dry mass is composed of biomolecules?
49. What is the general structure of an amino acid?
50. What is the role of mRNA?
51. Evaluate the importance of water in biomolecule function.
52. Which monosaccharides make a sucrose molecule?
53. How does the body use stored lipids for energy?
54. What are proteins made of?
55. Differentiate between the structure of DNA and RNA
56. Briefly describe the function of DNA.
57. Name three hexose sugars.
58. Name the four major types of biomolecules.
59. What is cellulose and where is it found?
60. What are the sources of monosaccharides?
61. What are enzymes?
62. Differentiate between anabolism and catabolism.
63. How does DNA store hereditary information?
64. What is the importance of enzymes in metabolism?
65. How do the three groups of carbohydrates differ in taste?
66. What are disaccharides? Give two examples.
67. What would happen if the body did not get enough essential amino acids?
68. What are proteins?
69. What are fatty acids?
70. What are essential amino acids?
71. Differentiate between Saturated and unsaturated fatty acids
72. What makes unsaturated fats healthier than saturated fats?
73. What is the role of tRNA?
74. How do lipids function as energy storage molecules?
75. What is the main function of biomolecules?
76. Why are lipids considered a better energy source than carbohydrates?
77. What are the three main types of lipids?
78. Name the protein responsible for oxygen transport in blood.
79. What are macromolecules?
80. What is the role of rRNA?
81. How many amino acids are commonly found in proteins?
82. Name three polysaccharides found in living organisms.
83. What is the most abundant carbohydrate in nature?
84. Differentiate between Monosaccharides and disaccharides
85. What is the function of phospholipids?
86. Name a carbohydrate found in milk.
87. What is the general formula of carbohydrates?
88. Why do plants convert monosaccharides into disaccharides?
89. Name two pentose sugars.
90. Name two sources of animal lipids.
91. Give an example of a storage polysaccharide in plants.
92. Name two common monosaccharides and two disaccharides.
93. What are the three types of carbohydrates?
94. Differentiate between Glycine and alanine.
95. What are the four nitrogenous bases in RNA?
96. What are the three types of RNA?
97. Name the monosaccharide units of sucrose.
98. Differentiate between the composition of DNA and RNA
99. What is the function of fibrin?
100. Name two proteins that function as hormones.
101. What are non-essential amino acids?
102. Why is cellulose not digestible by humans?
103. What are phospholipids?

Long Questions

1. Explain how the information in DNA is converted to information on RNA and then into proteins.
2. Discuss the significance of carbohydrates as an energy source.
3. Define biomolecules. Describe the structure and functions of carbohydrates.
4. Describe the structure of nucleic acids (DNA and RNA) and explain their functions.
5. Explain the functions of different types of biomolecules in living organisms.
6. What are lipids? Discuss their types, sources, and functions.
7. Explain the differences between DNA and RNA in detail.
8. Describe the process of DNA replication and its importance in cell division.
9. Discuss the role of RNA in protein synthesis.
10. Explain the classification of carbohydrates with examples.
11. What are phospholipids? Explain their role in the structure of cell membranes.
12. What are essential and non-essential amino acids? Why are essential amino acids important?
13. Define metabolism and explain its two main types: anabolism and catabolism.
14. Describe the role of enzymes in biochemical reactions.
15. Explain the double helix structure of DNA, and discuss the base pairing in this structure.
16. Describe the role of different types of proteins in biological systems.
17. Discuss the discovery of the double helix structure of DNA and explain its significance.
18. What are fatty acids? Explain their types.
19. Describe the basic structure of fats and oils. Explain how lipids play a role in energy storage.
20. Discuss the functions of proteins.
21. Describe how lipids are involved in energy storage and insulation.
22. Write a comprehensive note on the structures and roles of the three classes of carbohydrates.
23. Describe the process of genetic information transfer from DNA to proteins.
24. Explain the process of transcription and translation in protein synthesis.
25. Explain the importance of dietary fiber in human health.
26. Describe the structure of proteins and explain their functions in living organisms.

Answer Key

1. d) Saturated
2. c) Lipids
3. d) R group (side chain)
4. c) Nucleotides
5. b) Organic solvents like alcohol
6. b) Watson and Crick
7. a) It provides structural support in plants
8. d) Cell membrane and cytoplasm
9. c) Thymine
10. a) Carry genetic information
11. c) Sunflower seeds
12. c) Fats
13. b) They contain double bonds in their hydrocarbon chains
14. d) Thymine
15. b) All chemical reactions in an organism
16. b) Ribosomes read mRNA to form proteins
17. d) Carries genetic code
18. d) Sugar, phosphate, nitrogenous base
19. b) Biochemistry
20. b) Haemoglobin
21. d) Complex molecules are broken down, releasing energy
22. c) Vitamin D
23. d) Haemoglobin
24. b) Chitin
25. c) Nucleus
26. b) Study of chemical processes within living organisms
27. b) Milk and dairy products
28. c) Pulses
29. c) Phosphate group
30. b) Anabolism
31. b) Watson and Crick
32. c) Nucleotides
33. a) (CH₂O)ₙ
34. b) Amino acids
35. b) Alcohol
36. d) tRNA
37. c) 3
38. b) Provide energy
39. d) Uracil
40. d) All chemical reactions in an organism
41. b) Maintains proper bowel movements
42. c) DNA
43. c) 9
44. c) Water
45. b) Keratin
46. b) Fats
47. c) 20
48. c) Hemoglobin
49. c) Vitamins
50. b) Uracil
51. c) Antibodies
52. b) Proteins
53. b) 1962
54. c) Butter
55. d) Anabolism
56. c) Amino acids
57. d) Glycerol and fatty acids
58. b) Actin
59. c) Synthesize proteins
60. c) mRNA
61. c) Cellulose
62. b) Enzymes
63. b) Glycogen
64. c) Carries genetic information from DNA to ribosomes for protein synthesis
65. b) Glucose and fructose
66. b) Unsaturated fatty acids
67. c) Nucleic acids
68. c) Monosaccharides
69. b) Cholesterol
70. c) Transcription
71. b) Cholesterol
72. c) Thymine
73. b) Proteins
74. c) Carbohydrates
75. d) Blood clotting
76. b) 93%
77. c) Glucose
78. b) Plant cell walls
79. d) Fatty acids and glycerol
80. d) Lactose
81. a) The structure and function of biomolecules
82. c) Glycogen
83. d) Energy supply
84. c) Catabolism
85. c) Phospholipids
86. c) Monosaccharides are single sugars
87. c) Glucose
88. b) Phospholipids
89. d) Provide energy
90. b) Transcription
91. d) Chitin
92. d) A segment of DNA that codes for a protein
93. b) Deoxyribose
94. c) Ribose
95. c) Fibrin