Which of the following describes conditions in a photosynthesizing cell exposed to high light intensity and low carbon dioxide concentration?
Correct answer: A. High ATP and NADPH levels, but low Calvin cycle activity
- A. High ATP and NADPH levels, but low Calvin cycle activity
- B. Low ATP and NADPH levels due to fast Calvin cycle activity
- C. Low ATP and NADPH levels due to weak light reactions
- D. High ATP and NADPH use because CO₂ fixation increases
Explanation
Under high light intensity and low CO₂ concentration, photosynthetic cells accumulate ATP and NADPH since the light reactions are active but the Calvin cycle is limited by the shortage of CO₂. Therefore, the correct description is high ATP and NADPH levels with low Calvin cycle activity.
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