Multiple choice

What are the two gases that animals exchange with their surroundings?

  1. Oxygen and carbon dioxide

  2. oxygen and nitrogen

  3. nitrogen and helium

  4. hydrogen and carbon dioxide

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

Animals perform cellular respiration, which requires oxygen to break down nutrients and produces carbon dioxide as a waste product. These are the two primary gases exchanged during breathing.