Answer for you
Organisms depend on other species for resources such as nutrients. Parasites live in or on another organism, which is called the host. The parasite takes what it needs from the host but the host receives nothing in return and often suffers as a result. An example of parasitism is the relationship between fleas and dogs. Fleas live on dogs and feed on their blood. The dog receives no benefit but the fleas are provided with food and a habitat. Fleas attach themselves to hairs and can spread from one host to another by jumping huge distances.
