Question

The Calvin cycle of photosynthesis begins when

A. light becomes available.
B. electrons leave a photosystem.
C. the reduction of carbon dioxide occurs.
D. carbon dioxide is attached to RuBP.

Answer 1

The Calvin Cycle of photosynthesis begins when carbon dioxide reacts with RuBP, which is a 5-carbon carbohydrate. The enzyme called enzyme called Rubisco joins the carbon dioxide and RuBP. So the answer to your question would be D. carbon dioxide is attached to RuBP