AP BIOLOGY

Detailed explanation-1: -A parasite is an organism that lives in or on a host. It derives food and nutrients from the host. Parasites harm the host. Leech is an example of a parasite.

Detailed explanation-2: -A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host. There are three main classes of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites. Entamoeba histolytica is a protozoan. A microscope is necessary to view this parasite.

Detailed explanation-3: -Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life.

Detailed explanation-4: -Parasitism is a nonmutual relationship between two organisms in which one benefits at the expense of the other. There are two types of parasites affecting living organisms: ectoparasites (living on the surface of host) and endoparasites (living in the body of host).