Question

which gases are exchanged at the alveoli? oxygen and nitrogen; oxygen only; oxygen, carbon dioxide and nitrogen; oxygen and carbon dioxide

Explanation:

In the alveoli of the lungs, oxygen from the inhaled air diffuses into the bloodstream and carbon - dioxide from the blood diffuses into the alveoli to be exhaled. Nitrogen is not significantly exchanged at the alveoli during normal respiration.

Answer:

D. oxygen and carbon dioxide