Question

Assertion :In CAM plants, carbondioxide is trapped by highly efficient PEP carboxylase Reason: CAM plants do not fix carbondioxide during night

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

Photorespiration is a wasteful pathway that occurs when the enzyme rubisco acts on oxygen rather than carbon dioxide. Some plants that are adapted to dry environments, such as cacti and pineapples, use the Crassulacean Acid Metabolism (CAM) pathway to minimize photorespiration.

Instead of fixing carbon during the day and pumping the OAA (oxaloacetate) to other cells, CAM plants fix carbon at night and store the OAA in large vacuoles within the cell. This allows them to have their stomates open when humidity tends to be higher and temperatures are cooler, avoiding water loss.

At night, CAM plants open their stomata, allowing to diffuse into the leaves. This $C{O}_2$ is trapped by PEP carboxylase to form OAA.

So, the correct option is C.