Question

Lungs have a large number of alveoli for

• A. Having spongy texture and proper shape
• B. More surface area for diffusion of gases
• C. More space for increasing volume of inspired air
• D. More nerve supply

Answer 1

Answer: (B)

More surface area for diffusion of gases

There are about 300 million alveoli in each of the lungs. These tiny air sacs provide an ideal site for the diffusion of the gases into and out of the blood (gas exchange). The alveoli have a very large surface area. This large surface area is the result of all the alveoli being small spheres.
Therefore, the correct answer is option B.