Past Paper - Photosynthesis PDF

1. Which of the following is NOT true of the Calvin cycle? A. CO₂ reacts with RuBP to form 2 molecules of PGA. B. RuBP is regenerated. C. Sunlight energy is converted to chemical energy in the form of ATP and NADPH. (Correct answer) D. PGA is reduced using ATP and NADPH....

1. Which of the following is NOT true of the Calvin cycle? A. CO₂ reacts with RuBP to form 2 molecules of PGA. B. RuBP is regenerated. C. Sunlight energy is converted to chemical energy in the form of ATP and NADPH. (Correct answer) D. PGA is reduced using ATP and NADPH. 2. Which of the following events does NOT occur during the light reactions of photosynthesis? A. ATP is synthesized B. Oxygen gas is produced C. NADPH is synthesized D. RuBP is regenerated using ATP (Correct answer) 3. During noncyclic photophosphorylation, water is oxidized and the electrons from water pass through photosystem II and photosystem I before reducing: A. Carbon dioxide B. NADP+ (Correct answer) C. Plastoquinones D. FAD E. Ribulose 1, 5-bisphosphate 4. Which of the following statements is NOT correct about ATP? A. ATP is generated during the light reactions of photosynthesis. B. ATP is generated during both aerobic and anaerobic cell respiration. C. ATP is generated during the Calvin cycle. (Correct answer) D. ATP is hydrolyzed during the glycolysis. 5. Which of the following statements is NOT correct about the Calvin cycle? A. CO₂ is fixed by RuBP B. The reactions of the cycle occur in the stroma of mesophyll cells. C. One PGA molecule is gained with every three turns of the cycle. (Correct answer) D. Three carbon dioxide molecules are fixed in each turn of the cycle. 6. With cyclic photophosphorylation: A. Photosystem II operates alone B. NADPH is generated C. O₂ is produced D. ATP synthesis occurs by chemiosmosis (Correct answer) 7. When photosystem II (P) loses electrons during the light reactions, it gains its lost electrons from: A. CO₂ B. H₂O (Correct answer) C. Light energy D. Oxygen E. Chlorophyll a 8. CAM and C4 pathways occur at different times and locations. C3 and C4 pathways occur at different: A. Locations within the leaf; times of day B. Seasons; locations within the leaf C. Times of day; locations within the leaf (Correct answer) D. Times of day; seasons 9. The word 'photophosphorylation' implies: A. Light is involved and ATP is hydrolyzed B. Light is involved and ADP is phosphorylated (Correct answer) C. Water is involved and ATP is hydrolyzed D. Water is involved and ADP is phosphorylated 10. If the sun suddenly stopped emitting "green" wavelengths of light: A. The light reactions of photosynthesis would stop, since both chlorophyll a and chlorophyll b are green pigments. B. Accessory pigments would harvest less light energy. (Correct answer) C. The action spectrum of photosynthesis would not change. D. The ATP synthesis rate would double. 11. On a dry day, lack of water can limit photosynthesis because: A. Water must be split in the light reactions. B. Synthesis of carbohydrates requires an aqueous environment. C. Stomata will close, preventing CO₂ uptake. (Correct answer) D. H⁺ ions are needed for ATP synthesis. 12. As discovered by Calvin, when algal cells are exposed to radioactive carbon dioxide in the light for only 1 second, the compound that is most quickly and most extensively labeled with radioactive C has how many carbon atoms? A. 2 B. 3 (Correct answer) C. 4 D. 5 E. 6 13. Which statement about carbohydrate biosynthesis during the dark reactions of photosynthesis (i.e. the Calvin cycle reactions) is NOT TRUE? A. RUBISCO is an enzyme required for carbon dioxide fixation. B. NADPH is the source of electrons for glucose biosynthesis. C. ATP is the energy source for glucose biosynthesis. D. The reactions occur in the photosynthetic membranes of chloroplasts. (Correct answer) E. Oxygen is not required. 14. Which of the following does NOT occur during the dark reaction of photosynthesis ? A. Utilization of NADPH B. Utilization of ATP C. Reduction of oxygen to produce water (Correct answer) D. Synthesis of glucose E. Utilization of carbon dioxide 15. What is a property of C4 plants, but not C3 plants? A. Initially fix carbon dioxide in mesophyll cells as 4-carbon long compounds. (Correct answer) B. Initially fix carbon dioxide in bundle sheath cells as 3-carbon long compounds. C. Initially fix carbon dioxide in mesophyll cells as 3-carbon long compounds. D. Initially fix carbon dioxide in bundle sheath cells as 4-carbon long compounds. E. Special leaf anatomy adapted for cold and wet climates. 16. Which statement about photosynthesis in C4 plants is NOT true? A. The first product of carbon dioxide fixation is a compound with 4 carbon atoms. B. C4 photosynthesis is an adaptation for plants living in hot, arid climates. C. Carbon dioxide is initially fixed in mesophyll cells, but the Calvin cycle is active in bundle sheath cells in leaves of C4 plants. D. Less ATP is used overall for sugar biosynthesis in C4 than in C3 plants. (Correct answer) E. Photorespiration is minimal in C4 plants compared to C3 plants. 17. Accessory pigments: A. Have no function in photosynthesis B. Transfer energy from chlorophyll to electron carriers C. Absorb light in the red wavelengths D. Allow photosynthetic organisms to use visible light over a broader range of wavelengths (Correct answer) E. Transfer electrons directly to NADP+ 18. Which contains more energy: one molecule of NADP or one molecule of NADP-H? A. One molecule of NADP. B. One molecule of NADP-H. (Correct answer) C. Both have the same energy. D. Both have no energy. E. One molecule of NADP-H has twice the amount of energy of one molecule of NADP. 19. During the light-dependent reactions, which compartment of the chloroplast acidifies? A. Stroma B. Thylakoid space (Correct answer) C. Intermembrane space D. Matrix