Question

Define breathing. Explain any three differences between inhalation and exhalation. (1 Mark)

Answer 1

• Breathing is a physical process in which the air moves in and out of the lungs.

• Breathing process involves inhalation and exhalation. (0.5 Mark)

  Inhalation	Exhalation
  Air is taken in.	Air is expelled out
  Volume of chest cavity increases.	Volume of chest cavity decreases.
  Diaphragm is pushed up (contracts).	Diaphragm is pulled down (relaxes).

  (0.5 Mark)