**Leaves**

Leaves are the primary structures in plants that exchange gases, specifically carbon dioxide and oxygen, through tiny openings called stomata. The process of gas exchange in leaves is known as respiration.

**Structure of Leaves**

Leaves are flat, thin, and typically green structures that emerge from stems. They are attached to the stem by a petiole and have a blade-like structure. The blade is the main part of the leaf, and it contains several important components for gas exchange.

**Stomata**

Stomata are small openings found on the surface of leaves. They are surrounded by specialized cells called guard cells, which control their opening and closing. Stomata are vital for gas exchange as they allow carbon dioxide to enter the leaf and oxygen to exit.

**Photosynthesis and Respiration**

Leaves not only exchange gases but also play a crucial role in the process of photosynthesis. During photosynthesis, leaves absorb sunlight, carbon dioxide, and water to produce glucose and oxygen. This process occurs in specialized structures within the leaf called chloroplasts.

On the other hand, during respiration, plants use oxygen and glucose to release energy. Respiration occurs in all living cells, including the cells found in leaves. Oxygen is taken in through the stomata, and carbon dioxide, a waste product of respiration, is released through the same openings.

**Conclusion**

In conclusion, leaves are the structures in plants that primarily exchange gases. They have stomata that allow for the entry of carbon dioxide and the exit of oxygen. Leaves also play a vital role in photosynthesis and respiration, which are essential processes for plant growth and survival.