Question

What is true of the Calvin cycle?

a. It occurs only in the dark.
b. Light energy is captured by chloroplasts.
c. It is the first stage of photosynthesis.
d. Sugar is produced.

Answer 1

The correct statement regarding the Calvin cycle is that sugar is produced. This cycle utilizes energy stored in ATP and NADPH from the light-dependent reactions to convert CO₂ into glucose. So the correct answer is Option d.

Step-by-step explanation:

Overview of the Calvin Cycle

The Calvin cycle is an integral part of photosynthesis and is the process by which glucose is synthesized. To clarify the choice given in the question, d. Sugar is produced is the correct statement about the Calvin cycle. Light energy captured in the light-dependent reactions of photosynthesis is stored in ATP and NADPH, which are then utilized in the Calvin cycle. The cycle itself does not require light directly and occurs in the stroma, not the thylakoid membranes where the light-dependent reactions take place.

This cycle involves the fixation of carbon dioxide, the reduction phase where the fixed carbon is reduced, and the regeneration of the ribulose 1,5-bisphosphate. ATP and NADPH provide the energy and reducing power for these biosynthetic reactions. Hence, the Calvin cycle is critical for the conversion of CO₂ into glucose in plants.