Question

Mammalian lungs have enormous number of minute alveoli, which permits more ______.

Options

• space for increasing the volume of inspired air

• surface area for diffusion of gases

• spongy texture for keeping lungs in proper-shape

• nerve supply to keep organs active when working

Answer 1

Mammalian lungs have enormous number of minute alveoli, which permits more surface area for diffusion of gases.

Explanation:

Approximately 300 million alveoli are thought to be present in a human lung. The purpose of this vast number of alveoli is to enhance the surface area of the lungs for gas diffusion.