MCQ 71:
What is the main function of the photosystem II complex in photosynthesis?
A) To synthesize glucose
B) To capture light energy and split water
C) To regenerate RuBP
D) To produce ATP
Answer: B) To capture light energy and split water
Explanation:
Photosystem II captures light energy and facilitates the photolysis of water, producing oxygen and electrons for the electron transport chain.
MCQ 72:
Which of the following statements is true about the energy conversions in photosynthesis?
A) Light energy is converted to heat energy.
B) Chemical energy is converted to kinetic energy.
C) Light energy is converted to chemical energy.
D) Electrical energy is converted to light energy.
Answer: C) Light energy is converted to chemical energy.
Explanation:
Photosynthesis involves converting light energy from the sun into chemical energy stored in glucose.
MCQ 73:
What is the function of the thylakoid lumen?
A) Site of glucose synthesis
B) Storage of chlorophyll
C) Site for proton accumulation during light-dependent reactions
D) Site for carbon fixation
Answer: C) Site for proton accumulation during light-dependent reactions
Explanation:
The thylakoid lumen accumulates protons during the light-dependent reactions, creating a proton gradient used to generate ATP.
MCQ 74:
Which of the following processes contributes to the regulation of water loss in plants during photosynthesis?
A) Photolysis
B) Stomatal closure
C) Carbon fixation
D) ATP synthesis
Answer: B) Stomatal closure
Explanation:
Stomatal closure helps regulate water loss during hot or dry conditions, impacting the rate of photosynthesis.
MCQ 75:
What is the primary advantage of using ATP and NADPH in the Calvin cycle?
A) They provide structural support.
B) They serve as energy carriers.
C) They fix carbon dioxide.
D) They release oxygen.
Answer: B) They serve as energy carriers.
Explanation:
ATP and NADPH provide the energy and reducing power needed for the reactions in the Calvin cycle to synthesize glucose from carbon dioxide.
MCQ 76:
Which of the following statements about chloroplasts is correct?
A) They are found only in root cells.
B) They contain chlorophyll and perform photosynthesis.
C) They are responsible for cellular respiration.
D) They store starch exclusively.
Answer: B) They contain chlorophyll and perform photosynthesis.
Explanation:
Chloroplasts contain chlorophyll and are the sites of photosynthesis in plant cells.
MCQ 77:
What is the main function of the granum in chloroplasts?
A) Gas exchange
B) Light absorption
C) Storage of glucose
D) Photosynthetic reaction site
Answer: D) Photosynthetic reaction site
Explanation:
Grana are stacks of thylakoids in chloroplasts where the light-dependent reactions of photosynthesis occur.
MCQ 78:
Which of the following types of plants primarily utilize the Calvin cycle during the day?
A) CAM plants
B) C4 plants
C) C3 plants
D) All of the above
Answer: C) C3 plants
Explanation:
C3 plants primarily utilize the Calvin cycle during the day, fixing carbon dioxide directly when light is available.
MCQ 79:
What role does the enzyme RuBisCO play in photosynthesis?
A) It synthesizes ATP.
B) It fixes carbon dioxide.
C) It splits water molecules.
D) It reduces NADP⁺.
Answer: B) It fixes carbon dioxide.
Explanation:
RuBisCO catalyzes the fixation of carbon dioxide onto RuBP in the Calvin cycle, initiating the process of carbon fixation.
MCQ 80:
Which of the following is a feature of the light-independent reactions?
A) They require light directly.
B) They occur in the stroma.
C) They produce oxygen.
D) They take place in thylakoids.
Answer: B) They occur in the stroma.
Explanation:
Light-independent reactions, or the Calvin cycle, take place in the stroma of chloroplasts and do not require light directly.
Leave a comment