Which structures regulate water loss and gas exchange in the leaves of plants?

Consider the process of gas exchange. Stomata allow carbon dioxide ( ${\mathrm{CO}}_2$ ) to enter the leaf for photosynthesis and oxygen ( $O2$ ) to exit as a byproduct.

Understand the role of stomata in water regulation. When stomata are open, water vapor can escape from the leaf, a process known as transpiration. This helps in cooling the plant and maintaining nutrient flow.