Which structure in plants helps prevent water loss?

The cuticle is a waxy layer that covers the surface of leaves and some stems, playing a crucial role in helping to prevent water loss from the plant. This protective barrier reduces the evaporation of water from the plant's tissues, particularly in dry or arid environments. The cuticle serves as a crucial adaptation, enabling plants to retain moisture and maintain hydration, which is essential for their overall health and survival.

In contrast, the leaf blade is primarily involved in photosynthesis, while stomata are openings that facilitate gas exchange and can lead to water loss if not properly regulated. Root hairs are responsible for the absorption of water and nutrients from the soil but do not directly prevent water loss from the plant. Thus, the cuticle's function as a waterproof barrier is integral to a plant's ability to conserve water effectively.