Question

How many molecules of water are needed by a green plant to produce one molecule of hexose?

• A. 6
• B. 12
• C. 24
• D. One only

Answer 1

The correct option is B 12

The process of water dissociation during photosynthesis is called as photo-oxidation of water. It requires the presence of Mn++, Ca+ and Cl${}^{-}$, a water oxidising enzyme and an unknown substance Z.

12 molecules of water and 6 molecules of CO${}_2$ is required by a green plant to produce 1 molecule of hexose.

So, the correct answer is option B.