Compared with inspired air, expired air contains

  1. more oxygen and less carbon dioxide
  2. less nitrogen
  3. less water vapour
  4. more carbon dioxide and less oxygen
Answer

D) more carbon dioxide and less oxygen

Respiration uses O₂ and produces CO₂. O Level Biology · Topic 9 Human Gas Exchange · 9.1 Human gas exchange

Biology MCQ · More O Level Biology: Human Gas Exchange MCQs · Practise