Final answer:
The cuticle is a waxy layer that prevents water from escaping a plant's leaves.
Step-by-step explanation:
The structure that prevents water from escaping a plant's leaves is the cuticle.
The cuticle is a waxy layer that covers the outer surface of the leaves and stems of plants. It acts as a waterproof barrier, preventing water loss through evaporation.
For example, imagine a plant growing in a hot and dry environment. The cuticle on its leaves helps to reduce water loss by creating a barrier that prevents excessive evaporation.
Learn more about Plant physiology