Question

In CAM plants, organic acid content

• A. Decreases during night
• B. Increases during day
• C. Increases during night
• D. Both A and B

Answer 1

The correct option is C Increases during night

In CAM plants, organic acid content increases during the night because the stomata remain open at the night and close during the daytime to conserve water. When stomata are open during the night, carbon dioxide is fixed by the action of phosphoenolpyruvate carboxylase to malic acid, this is called as acidification. During daytime, when the stomata are closed, malic acid is converted to pyruvic acid and carbon dioxide, this is called as deacidification. Hence acid concentration increases at night and decreases at daytime. So, the correct answer is 'Increases during night'.