Question

In CAM-plants, carbon dioxide required for photosynthesis enters the plant body during

• A. Day time throught the lenticels
• B. Night, through the open stomata
• C. Day time through open stomata
• D. Night when the hydathodes are open

Answer 1

The correct option is B

Night, through the open stomata

In CAM-plants, the stomata open at night. This allows the entry of carbon dioxide in the leaves. The carbohydrate stored in plants are converted to PEP by glycolysis, which is carboxylated to malic acid. Thus, carbon dioxide is fused in plants as malic acid, which is stored inside vacuole. During day time, stomata closes and the malate is transported to chloroplast and undergoes decarboxylation and the released carbon dioxide is fixed by Calvin cycle.