What keeps the trachea open?

  1. The diaphragm
  2. Cilia
  3. Mucus
  4. Rings of cartilage
Answer

D) Rings of cartilage

C-shaped cartilage stops collapse. O Level Biology · Topic 9 Human Gas Exchange · 9.1 Human gas exchange

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