Question

The exchange of gases in the alveoli of the lungs takes place by ______.  

Options

• osmosis

• simple diffusion

• active transport

• either osmosis or simple diffusion

Answer 1

The exchange of gases in the alveoli of the lungs takes place by simple diffusion. 

Explanation:

Simple diffusion of oxygen from alveolar air into the blood and diffusion of \[\ce{CO2}\] from the blood into alveolar air constitute the gaseous exchange.