Which respiration organ is common to both reptiles and birds?

• A. Lungs
• B. Gills
• C. Skin
• D. Trachea

Answer: (A)

Respiration in both reptiles and birds relies on lungs as the primary site of gas exchange. Gills are used by many aquatic animals, not by reptiles or birds. While some animals can exchange gases through the skin, reptiles and birds rely on their lungs for most of their oxygen intake. The trachea is the airway that channels air to the lungs, but the actual gas exchange happens in the lungs themselves. Birds have exceptionally efficient lungs with additional air sacs to maximize oxygen delivery, while reptiles have lungs that they ventilate with rib movements. So the common respiration organ is the lungs.