The waste materials produced during the metabolic activities are toxic to the body and must not be accumulated inside, and therefore it has to be excreted out from the body by the process of excretion.
Importance of excretion
Certain waste and harmful substances are formed during the functioning of body cells. Examples of such harmful waste products are urea, etc. When these toxic materials are not removed from the body, they get mixed with blood and can damage the cells of the body. The removal of such poisonous waste materials is therefore necessary.