Multiple choice

Animals inhale _______ gas; while exhale ________ gas.

  1. Nitrogen/Oxygen

  2. Carbondioxide/Oxygen

  3. Oxygen / Carbon dioxide

  4. Argon / Nitrogen

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

Animals take in oxygen for cellular respiration and release carbon dioxide as a waste product. This gas exchange is fundamental to aerobic respiration in all animals.