Instructions:
* Section A: Answer all 40 multiple-choice questions on the answer sheet provided.
* Section B: Answer all 6 short answer questions in the spaces provided.
* Section C: Answer all 4 structured questions in the spaces provided.
* Show all working where applicable.
* The use of non-programmable calculators is permitted.
Section A: Multiple Choice Questions (40 Marks)
1. Which of the following is a characteristic of prokaryotic cells?
a) Presence of a nucleus
b) Membrane-bound organelles
c) Circular DNA
d) Extensive endoplasmic reticulum
2. The primary function of the Golgi apparatus is:
a) Protein synthesis
b) Lipid synthesis
c) Modification and packaging of proteins
d) Cellular respiration
3. Which organelle is responsible for ATP production in eukaryotic cells?
a) Lysosome
b) Mitochondria
c) Ribosome
d) Peroxisome
4. The cell wall of plant cells is primarily composed of:
a) Chitin
b) Peptidoglycan
c) Cellulose
d) Pectin
5. Which of the following is a function of lysosomes?
a) Photosynthesis
b) Intracellular digestion
c) Protein folding
d) DNA replication
6. The process by which water moves across a selectively permeable membrane is
called:
a) Diffusion
b) Active transport
c) Osmosis
d) Facilitated diffusion
7. Which of the following is a function of proteins?
a) Energy storage
b) Genetic information storage
c) Catalyzing biochemical reactions
d) Building cell walls
8. Which of the following is a disaccharide?
a) Glucose
b) Fructose
c) Sucrose
d) Glycerol
9. The building blocks of proteins are:
a) Fatty acids
b) Amino acids
c) Nucleotides
d) Monosaccharides
10. Which of the following is a component of nucleic acids?
a) Triglycerides
b) Cholesterol
c) Phosphate group
d) Glycogen
11. Which of the following is a saturated fatty acid?
a) Contains double bonds.
b) Is liquid at room temperature.
c) Is solid at room temperature.
d) Is found in plant oils.
12. What is the role of cholesterol in cell membranes?
a) To increase fluidity at low temperatures.
b) To decrease fluidity at all temperatures.
c) To transport water.
d) To synthesize proteins.
13. Which type of transport requires energy?
a) Osmosis
b) Facilitated diffusion
c) Active transport
d) Simple diffusion.
14. What is the main function of the smooth endoplasmic reticulum?
a) Protein synthesis.
b) Lipid synthesis.
c) Cellular respiration.
d) DNA replication.
15. Which of the following is a function of the nucleus?
a) ATP production.
b) Storage of genetic information.
c) Protein modification.
d) Detoxification.
16. Which of the following is a function of the cytoskeleton?
a) Energy storage.
b) Cell structure and movement.
c) Lipid synthesis.
d) Photosynthesis.
17. What are the products of cellular respiration?
a) Glucose and oxygen.
b) Carbon dioxide and water.
c) Glucose and carbon dioxide.
d) Water and oxygen.
18. What is the main product of photosynthesis?
a) Carbon dioxide.
b) Water.
c) Glucose.
d) ATP.
19. Which of the following is a component of RNA?
a) Deoxyribose.
b) Thymine.
c) Uracil.
d) Double helix.
20. What is the function of enzymes?
a) Store genetic information.
b) Catalyze biochemical reactions.
c) Provide structural support.
d) Transport molecules.
21. What is the difference between saturated and unsaturated fats?
a) Unsaturated fats contain double bonds.
b) Saturated fats are liquid at room temperature.
c) Unsaturated fats are found in animal products.
d) Saturated fats are healthier.
22. Which of the following is a function of carbohydrates?
a) Catalyzing reactions.
b) Energy storage and structural support.
c) Genetic information storage.
d) Transporting oxygen.
23. What is the role of ribosomes in a cell?
a) Lipid synthesis
b) Protein synthesis
c) Detoxification
d) Cellular respiration
24. Which of the following is a function of peroxisomes?
a) Photosynthesis
b) Breakdown of fatty acids and detoxification.
c) Protein modification.
d) DNA replication.
25. What is the process of a cell engulfing large particles called?
a) Exocytosis
b) Endocytosis
c) Diffusion
d) Osmosis.
26. Which of the following is a component of the cell membrane?
a) Cellulose
b) Chitin
c) Phospholipids
d) Peptidoglycan
27. What is the function of the vacuole in plant cells?
a) Protein synthesis.
b) Storage of water and nutrients.
c) ATP production.
d) DNA replication.
28. What is the function of the chloroplast?
a) Cellular respiration.
b) Photosynthesis.
c) Protein modification.
d) Lipid synthesis.
29. Which of the following is a function of nucleic acids?
a) Energy storage.
b) Genetic information storage.
c) Catalyzing reactions.
d) Providing structural support.
30. What is the function of the centrioles?
a) Protein synthesis.
b) Cell division.
c) Lipid synthesis.
d) Photosynthesis.
31. What is the term for a solution with a higher solute concentration?
a) Hypotonic
b) Isotonic
c) Hypertonic
d) Equilibrium.
32. What is the function of the rough endoplasmic reticulum?
a) Lipid synthesis.
b) Protein synthesis.
c) Detoxification.
d) Cellular respiration.
33. Which of the following is a function of microfilaments?
a) Cell division.
b) Cell movement and structure.
c) Protein synthesis.
d) DNA replication.
34. What are the building blocks of lipids?
a) Amino acids.
b) Monosaccharides.
c) Fatty acids and glycerol.
d) Nucleotides.
35. What is the function of the nucleolus?
a) Lipid synthesis.
b) Ribosome synthesis.
c) ATP production.
d) DNA replication.
36. What is the process of releasing substances from a cell called?
a) Endocytosis.
b) Exocytosis.
c) Diffusion.
d) Osmosis.
37. What is the function of intermediate filaments?
a) Cell division.
b) Cell structure and support.
c) Protein synthesis.
d) DNA replication.
38. Which of the following is a function of microtubules?
a) Cell division and movement.
b) Lipid synthesis.
c) Protein synthesis.
d) DNA replication.
39. What is the function of tight junctions?
a) Communication between cells.
b) Strengthening cell connections.
c) Preventing leakage between cells.
d) Transporting materials between cells.
40. What is the function of gap junctions?
a) Strengthening cell connections.
b) Preventing leakage between cells.
c) Communication between cells.
d) Transporting materials across membranes.
Section B: Short Answer Questions (24 Marks)
41. (4 marks) Explain the difference between simple diffusion and facilitated
diffusion.
42. (4 marks) Describe the structure and function of a ribosome.
43. (4 marks) Outline the role of enzymes in biological reactions.
44. (4 marks) Differentiate between DNA and RNA.
45. (4 marks) What are the main functions of lipids in living organisms?
46. (4 marks) Explain the importance of the cell membrane in maintaining
homeostasis.
Section C: Structured Questions (32 Marks)
47. (8 marks)
a) Describe the structure of a phospholipid molecule. (4 marks)
b) Explain how phospholipids arrange themselves to form a cell membrane in an aqueous
environment. (4 marks)
48. (8 marks)
a) Compare and contrast the structure and function of mitochondria and chloroplasts. (4
marks)
b) Explain the significance of these organelles in energy transformation. (4 marks)
49. (8 marks)
a) Describe the process of active transport. (4 marks)
b) Provide two examples of active transport in biological systems and explain their
importance. (4 marks)
50. (8 marks)
a) Describe the fluid mosaic model of the cell membrane. (4 marks)
b) Explain how the fluid mosaic model contributes to the functions of the cell membrane.
(4 marks)
