AP BIOLOGY

Detailed explanation-1: -A thick, waxy coating of cutin is present on the epidermis of desert plants. It helps in reducing the loss of water in desert plants. Suberin, which is also a chemical, is present in the walls of dead cork cells. It makes these cells impervious to gases and water.

Detailed explanation-2: -Desert environments are so dry that they support only extremely sparse vegetation; trees are usually absent and, under normal climatic conditions, shrubs or herbaceous plants provide only very incomplete ground cover.

Detailed explanation-3: -In xerophytic plants (cactus), the epidermal layer secretes a thick and waxy layer called the cuticle. This layer closes the stomata and prevents water loss by the transpiration process (water-resistant layer). As the cactus plant lives in a water-deficit area such thick and waxy cuticle is seen.

Detailed explanation-4: -Leaves and stems of many desert plants have a thick, waxy covering, keeping the plants cooler and reducing evaporative loss.