Cilia in the airways

  1. kill bacteria directly
  2. sweep mucus up towards the throat
  3. pump air into the alveoli
  4. absorb oxygen
Answer

B) sweep mucus up towards the throat

Mucociliary escalator. AS & A Level Biology · Topic 9 Gas Exchange · 9.1 The gas exchange system

Biology MCQ · More A Level Biology: Gas exchange MCQs · Practise