Question

Which of the following is not true regarding alveoli?

• A. It is a single-celled sac of air
• B. It is a multi-celled sac of air
• C. It has thin walls
• D. It facilitates the exchange of oxygen and carbon dioxide molecules into or away from the bloodstream.

Answer 1

The correct option is B It is a multi-celled sac of air

The alveoli are single-celled sacs of air with thin walls. It facilitates the exchange of oxygen and carbon dioxide molecules into or away from the bloodstream.