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JAMB Biology 2004 Question 17

Question 17

Respiration

The surface of an alveolus in a mammal is well supplied with tiny blood vessels known as

  1. A.arterioles
  2. B.venules
  3. C.arteries
  4. D.capillaries
Show the answer and explanation

Answer: D (capillaries)

Explanation

Each alveolus is covered with a network of capillaries. Their thin walls let oxygen and carbon(IV) oxide diffuse quickly.