Biology 5090 · O Level · Human gas exchange

Human gas exchange — practice question

The proportions of each gas in inspired air and expired air are measured while a student is at rest and while the student is exercising. The findings are shown. Using the data, which statement is not correct?

  • AThe difference between the percentages of carbon dioxide in expired air when exercising and in expired air when resting is 1.5.
  • BWhen resting, the difference between the percentage of oxygen in inspired and expired air is due to oxygen being used by respiration in the body.
  • CInspired air contains 52.5 times more oxygen than carbon dioxide.
  • DThe percentage of oxygen taken from inspired air is the same as the percentage of carbon dioxide added to expired air when exercising.

Worked solution & mark scheme

This 1-mark question has a full step-by-step worked solution and mark scheme.

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI