Final answer:
Desert plants have adaptations like hair on leaves and a thick cuticle which help in preventing water loss by reducing transpiration and providing protection against harsh desert conditions.
Step-by-step explanation:
Plants living in deserts have adaptations such as hair on leaves and a thick cuticle to serve primarily one major purpose - preventing water loss. The thick waxy cuticle significantly reduces transpiration by providing a robust barrier against water evaporation from the plant surface. Additionally, leaf hairs (also referred to as trichomes) can provide shade to the leaf surface, reduce air flow across the leaf which reduces water loss, and in some cases, can trap moisture around the leaf. These features are crucial for survival in arid environments where water is scarce.
Desert plants, or xerophytes, have to adapt to harsh conditions with efficient use of available water. The ability of cacti and other desert-adapted plants to conduct photosynthesis during cooler nighttime hours minimizes water loss, as it allows them to keep their stomata closed during the hot day, further contributing to water conservation. This process of temporary carbon fixation and storage is an adaptation in response to the extreme desert conditions, demonstrating the remarkable evolutionary strategies plants have developed to manage their water use.