The first step in dark reaction of photosynthesis is

Options

(a) formation of ATP
(b) ionization of water
(c) attachment of CO₂ to a pentose sugar
(d) excitement of electron of chlorophyll by a photon of light

Correct Answer:

attachment of CO₂ to a pentose sugar

Explanation:

In C₃ plants, the carbon dioxide combines with ribulose 1, 5-diphosphate (RuDP) (now called RuBP – Ribulose 1, 5 bisphosphate) and gives rise to a 3-C compund, phosphoglyceric acid. It is first stable product of C₃ cycle. The process can be called as Calvin cycle.