Standard Science Primary 5 Systems

Which of the following correctly describes the change in the amount of nitrogen, oxygen, and carbon dioxide in exhaled air compared to inhaled air?

A Nitrogen: Increases; Oxygen: Decreases; Carbon Dioxide: Same
B Nitrogen: Same; Oxygen: Decreases; Carbon Dioxide: Increases
C Nitrogen: Decreases; Oxygen: Same; Carbon Dioxide: Increases
D Nitrogen: Same; Oxygen: Increases; Carbon Dioxide: Decreases
Show Worked Solution

Worked Solution

Step 1: Our bodies use oxygen for respiration, so exhaled oxygen is lower. Step 2: Respiration produces carbon dioxide, so exhaled CO2 is higher. Step 3: Nitrogen is not used by the body, so the amount remains the same.

Correct answer: Nitrogen: Same; Oxygen: Decreases; Carbon Dioxide: Increases

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