define mutualism, commensalism, parasitism.
Mutualism is a type of symbiotic relationship between two species where both organisms benefit from the interaction. Both species involved in the interaction contribute something to the survival and well-being of the other, such as a food source or protection against predators.
Commensalism is a symbiotic relationship in which one organism benefits while the other is neither harmed nor helped by the interaction. In this type of relationship, the commensal organism depends on the host for a place to live, food, or transportation, while the host remains unaffected by the presence of the commensal organism.
Parasitism is a form of symbiotic relationship where one organism, called the parasite, is dependent on the other, called the host, for its survival. The parasite derives nourishment or other benefits from the host, often causing harm or loss to the host in the process. The host organism is usually weakened by the relationship but not always killed outright.