Question

The reactions of the Calvin cycle are not directly dependent on light, but they usually do not occur at night. Why? Group of answer choices
a.The Calvin cycle requires products only produced when the photosystems are illuminated. It is often too cold at night for these reactions to take place.
b.At night, no water is available for the Calvin cycle.
c.Plants usually open their stomata at night.
d.Carbon dioxide concentrations decrease at night.

Answer 1

Answer:

The correct answer is a The calvin cycle requires products only produced when the photsystems are illuminated .It is often too cold at night for the reaction to take place.

Explanation:

It is true that the reactions of calvin cycle are not directly depends on light but depends on the products such as ATP and NADPH produced during light reaction.

       ATP and NADPH is formed by the illumination of photosystems by sun light.So during night time there is no chance for the light dependent illumination of the photosystems.

    As a result the ATP and NADPH are not formed during night .That"s why reactions of calvin cycle does not occur at night.