Question

Gaseous exchange takes place at ____________.

• A. Alveoli
• B. Bronchi
• C. Bronchioles
• D. Trachea

Answer 1

The correct option is A

Alveoli

The correct option is A:

Explanation of the correct option:

1. Alveoli are the balloon-like structures present at the terminal end of each bronchiole.
2. Alveoli are the functional units of the lungs.
3. The walls of alveoli have a large number of blood capillaries through which gaseous exchange takes place between alveoli and blood.
4. It is the site of gaseous exchange between the respiratory system and circulatory system.

Explanation of the incorrect options:

Option B:

The trachea is divided into two small tubes through which air passes to the bronchioles, called bronchi.

Option C:

Each bronchus divides into a large number of small tubes inside the lungs, these small tubes are called bronchioles.

Option D:

The trachea is a tube-like structure also called wind pipe. The trachea divides to form two bronchi.

Final Answer:

Gaseous exchange takes place at alveoli.