Question

Use your knowledge of lipids to explain why desert plants need the waxy coating on their leaves to survive.Read the paragraph below, and answer the question on the next slide. There are many differences between plants found in wet climates and plants found in deserts. One of the main structural differences is the presence of waxy leaves. Desert plants, such as the creosote bush and the date palm tree, have a coating of wax on their leaves. Plants found in wet climates, such as the lady fern and the maple tree, do not have a waxy coating on their leaves.

Answer 1

Desert plants require a waxy coating on their leaves primarily to minimize water loss in an environment where moisture is scarce. This waxy layer, composed of lipids, serves as a barrier that reduces evaporation. In the arid conditions of the desert, where temperatures can be high and humidity low, the potential for water loss through transpiration is significant. The waxy cuticle on desert plants helps to create a protective exterior that limits the escape of water vapor from the leaf surface, allowing these plants to conserve the limited water they have available.

In contrast, plants in wet climates generally have ample water availability, and their leaf structures have adapted to facilitate gas exchange and photosynthesis without the need for such a strong barrier. The absence of a waxy coating in these plants allows for greater gas exchange, which is essential for photosynthesis, especially in environments where water is not a limiting factor.

Therefore, the waxy coating is a vital adaptation that enables desert plants to thrive in conditions that would otherwise lead to excessive water loss and stress.