Gases must dissolve before diffusing, so the alveolar surface is

  1. ciliated
  2. lined with cartilage
  3. waxy
  4. moist
Answer

D) moist

A thin water layer lines alveoli. AS & A Level Biology · Topic 9 Gas Exchange · 9.1 The gas exchange system

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