Question

Air flow into and out of the lungs is an example of what?

Diffusion

Osmosis

Bulk flow

Active Transport

Facilitated Diffusion

Answer 1

The right answer is :

bulk flow.

The bulk flow or mass flow is defined as the movement of gases occur from high partial pressure of gaseous region to the lower partial pressure of gaseous region.

Now there is high concentration of oxygen in the atmosphere as compared to lungs region. That's why because of pressure difference of oxygen. Oxygen moved to lungs.

Similarly during expiration, there is found higher partial pressure f carbon dioxide in the lungs and found lower in the lungs. That's why carbon dioxide moves outside the lungs.