Answer Briefly Following

Answer briefly the following: Why do our body cells require oxygen? What is the difference … What is the role of epiglottis…

Answers:
  1. Body cells require oxygen for the break-down of glucose and release energy for carrying out various life functions.
  2. Breathing is a simple physical process of drawing in air through the nostrils and expelling it out.
    Respiration is a chemical process which involves the breakdown of food and release energy.
  3. The by- products formed are
    1. Carbon – dioxide
    2. water
  4. Blood.
  5. Epiglottis closes the wind pipe at the time of swallowing.