Parasite : An organism that lives permanently or temporarily on or inside the body of another organism and depends fully or partly on the host organism for its nutrition is called a parasite.
1. Their Physiological systems are of simple type.
2. The external body covering of the endoparasites is firm but semipermeable.
3. The parasites have higher reproductive capacity.
On the basis of the location of parasites on the host body, the parasites are of two types, Ectoparasite and Endoparasite.
1. Ectoparasite : They live on the outer side of the host body, e.g. Leech.
2. Endoparasite : They live inside the host body, e.g. malarial parasite.
Parasite and parasitism : We have learnt earlier that the round worm lives asa parasite inside the host body and gets nourishment by taking digested food materials from he intestine of its host. So it is called an endoparasite. Round worm gets shelter and nutrition from the host body, as a result of which the host suffers from anemia and malnutrition. The relationship that is formed between the host and the parasite is known as parasitism.