Why dark reaction in plant occurs in presence of light and though known dark reaction?

Question

Why dark reaction in plant occurs in presence of light and though known dark reaction?

Answer 1

If I understand your question...the dark reactions don't require direct light, but the products from the light reactions, so they can still perform in light, but don't require light themselves.

Some plants (CAM-live in hot, dry conditions usually) can halt the process of Carbon fixing (light dependent, part of the Calvin cycle) until night time so they do not release too much water when they open their stomata due to heat.