(d) One organism is benefited, other is affected.

Parasitism is a kind of relationship between two species in

which one derives its food from the other (host). Parasitism also involves shelter,

in addition to food obtained by a parasite. Parasites may be ectoparasites or

endoparasites. Ectoparasites live on the surface of their host while endoparasites

live inside the body of the host.

Examples of Parasitism

(i) Cucuta growing on shoe flower plant

(ii) Head lice and humans

(iii) Ascaris, Taenia, Plasmodium causing diseases in humans