The exchange of oxygen and carbon dioxide between air in alveoli and blood in capillaries occurs by
A)diffusion.
B)osmosis.
C)filtration.
D)active transport.

Question

Quizplus · Accepted Answer

The exchange of gases between air in alveoli and blood in capillaries occurs by diffusion. This is because there is a concentration gradient of oxygen and carbon dioxide between the air and blood, and the gases move from an area of higher concentration to an area of lower concentration until an equilibrium is reached. Osmosis, filtration, and active transport are not involved in this process.

The Exchange of Oxygen and Carbon Dioxide Between Air in Alveoli