All terms in this list:

parasite: An organism that lives off the energy of other living things.

Host: An organism that a parasite lives in or gets nourishment from.

Limiting Factor: A condition that interferes with the growth or survival of an organism.

Commensalism: A relationship between organisms in which one species benefits and the other species neither nor harmed by the interaction.

Symbiosis: A relationship in which two species exist together and at least one of the species benefits from the interaction.

Niche: The role that an organism plays in its ecosystem.

Community: A group consisting of all plants and animals that live in the same area.

Stimulus: Something that causes a reaction.

Competition: A form of interaction that occurs when organisms occupy a similar niche or need the same food, water, or space.

Ecosystem: A community of interacting organisms.

Habitat: The specific place where on organism lives.

Mutualism: A relationship between organisms in which both species benefit from the interaction.

Population: A group of plants or animals of the same species that live together in a area.

Cooperation: Working together to help each other survive.