a group of organisms of the same species living together in an ecosystem

all the populations living in an ecosystem

the part of an ecosystem in which an organism lives

an organism’s role in an ecosystem

the variety of species in an ecosystem

an organism that makes its own food

a sequence of connected producers and consumers

an organism that eats other organisms

a group of connected food chains in an ecosystem

a diagram that shows how energy is lost at each level in a food chain

the struggle among organisms for limited resources in an area

the measure of a population’s size in relation to the size of the area in which the population lives

a close relationship between organisms of different species in which one or both of the organisms benefit

an organism that benefits from its relationship with an organism that it lives in or on while the other organism is harmed

the organism that a parasite lives in or on