Question

Which statement regarding the Calvin cycle is true?

A. The Calvin cycle takes place in the thylakoid membrane.
B. The Calvin cycle requires light energy for its completion.
C. The Calvin cycle produces glucose directly.
D. The Calvin cycle is part of the light-dependent reactions.

Answer 1

The true statement about the Calvin cycle is that it uses chemical energy from ATP and NADPH to transform CO2 into GA3P, which can eventually form glucose. It occurs in the chloroplast stroma, not directly in the thylakoid membrane where the light-dependent reactions take place.

Step-by-step explanation:

The Calvin cycle is a part of photosynthesis that occurs in the stroma of chloroplasts, following the light-dependent reactions that take place in the thylakoid membranes. While the light-dependent reactions harness solar energy to produce ATP and NADPH, the Calvin cycle uses the chemical energy stored in these molecules to incorporate carbon from CO₂ into organic molecules. Specifically, the Calvin cycle does not produce glucose directly; instead, it produces a three-carbon sugar, glyceraldehyde-3-phosphate (GA3P), which can later combine to form glucose. Thus, the correct statement regarding the Calvin cycle is that it uses energy derived from ATP and NADPH to make GA3P from CO₂.