Question

Why do stomata close during dry periods?

Answer 1

The stomata closes during dry periods because it may let water out during gas exchange, and that isn't good when there is no source of water to replenish it.

Answer 2

Most of the stomata are located in the plant's leaves. ... Stomata are adaptations that help plants survive. When they are open, they allow carbon dioxide to enter. When they are closed, they help prevent the loss of water from the plant.