symbiotic relationships

Currently, in our science class we've been studying symbiotic relationships. In a symbiotic relationship, at least one organism has to be helped. The three symbiotic relationships are commensalism, mutualism, and parasatism. Commensalism is when one organism is nuetral and the other is helped. An example of commensalism is a human and lice. The lice is helped by the human because it lives on the human hairs and feeds on extremely small amounts of blood drawn from the scalp and the human is nuetral because it is not harmed or helped. Mutualism is when both organisms are helped. An example of mutualism is a clownfish and a sea anenome. The sea anenome is helped by the clownfish bringing it food to survive and in return the sea anenome helps the clownfish by providing safety from other organisms. Parasatism is when one organism is helped and the other is harmed. An example of parasatism is a human and a tick. The tick is helped and the human is harmed in the symbiotic relationship they share. The human is harmed by the tick biting at the human and possibly giving the human lime disease and the tick is helped by the human giving it shelter and blood for food.