Multiple choice

In the lungs, gaseous exchange takes place in

  1. the alveoli

  2. the bronchioles

  3. the bronchi

  4. the trachea

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The alveoli are tiny air pockets at the ends of the bronchioles. Oxygen from the air diffuses into the blood capillaries in their walls and carbon dioxide diffuses out.