(a) State three common features of respiratory organs of animals. (b) Write two points of difference between aerobic respiration and anaerobic respiration.

(a) Three common features of respiratory organs of animals :
(i) Animals absorbs oxygen from water or air hence have a structure that increases the surface area which is in contact with the oxygen rich atmosphere.
(ii) Since exchange of oxygen-carbon dioxide has to take place across this surface, it is very fine and delicate.
(iii) ln order to protect this surface, it is placed within the body, so there are passages that take air to this area.
(b) Differences between aerobic and anaerobic respiration:
Aerobic respiration:-
(i) Oxygen is used to breakdown glucose.
(ii) Glucose is broken down completely to release large amount of energy.
Anaerobic respiration:-
(i) Do not involve oxygen to breakdown glucose.
(ii) Breakdown of glucose is incomplete to release small amount of energy.