Gaseous exchange takes place in the:

Correct option is D

Ans. (d) Sol. The correct answer is (d) Alveoli.
Alveoli are tiny air sacs in the lungs where the actual exchange of gases (oxygen and carbon dioxide) occurs between the air and the bloodstream. The walls of the alveoli are extremely thin and are surrounded by a network of capillaries that facilitate the exchange of gases.
Explanation of each option:
· (a) Nose: The nose is involved in filtering, warming, and humidifying air before it enters the respiratory system, but it is not the site of gas exchange.
· (b) Trachea: The trachea, or windpipe, is a passageway for air from the nose to the lungs. It does not participate in gas exchange but serves as a conduit.
· (c) Bronchus: The bronchus (or bronchi) are the airways that lead from the trachea to the lungs. They do not participate directly in gas exchange but distribute air to the alveoli where gas exchange occurs.
· (d) Alveoli: Correct answer. The alveoli are the primary sites of gas exchange, where oxygen is transferred from the air into the blood and carbon dioxide is transferred from the blood into the air to be exhaled.
Thus, alveoli are the correct site for gaseous exchange in the respiratory syste