Question

In xerophytes, photosynthesis occurs in –
A. Root
B. Modified stem
C. Scaly leaves
D. Stomata

Answer 1

Hint: Xerophytic plants are the desert plant, in which the plants adapt some adaptations according to the climatic condition. CAM pathway usually occurs in xerophytic plants.

Complete answer: Xerophytes live in a shortage of water. So, they have special adaptive features to store or reduce the loss of water through transpiration, so that photosynthesis and respiration can be carried out. In Cacti, the leaves are reduced to spines. Therefore, photosynthesis occurs in the stem. The stem has many packed cells in the cortex which can easily store water and the epidermis has a waxy cuticle, in order to reduce the water loss. The cacti can close their stomata during the day, this decreases water loss. Then, they open the stomata at night to let in carbon dioxide for photosynthesis. This process of photosynthesis is known as CAM photosynthesis.
So, the answer is option B.

Additional information:Xerophytes are plants which can survive in desert conditions. The deserts provide a very small amount of water, so the plants also receive very less water or moisture. So, in order to survive the extreme situations of heat and water scarcity, the plants growing in deserts have
adaptations which allow them to survive in these harsh conditions. These plants are called succulents. Succulents are typically found in deserts.

Note: The process of photosynthesis occurs in the green stem of succulents. Leaves in succulents are reduced to spines. So, the leaves can not carry out photosynthesis. This is an escape mechanism of the xerophytes for reducing the loss of water due to transpiration.