Here's why:

* Stomata: Plants have tiny openings on their leaves called stomata. These stomata open and close to regulate gas exchange.

* Carbon Dioxide Intake: Plants need carbon dioxide for photosynthesis, the process by which they produce food. Stomata open to allow carbon dioxide to enter the plant.

* Water Loss: When stomata are open, water vapor can also escape from the plant through a process called transpiration.

This process of gas exchange and water loss through stomata is essential for plant survival. It allows them to carry out photosynthesis while also maintaining their water balance.