| A | B |
|---|
| organism | a living things |
| habitat | an environment that provides the things a specific organism needs to live, grow, and reproduce |
| biotic factor | a living or once living part of an organism's habitat |
| abiotic factor | a nonliving part of an organism's habitat |
| population | all the members of one species living in the same area |
| community | all the different populations that live together in a certain area |
| ecosystem | the community of organisms that live in a particular area, along with their nonliving environment |
| limiting factor | an environmental factor that causes a population to decrease in size |
| producer | an organism that can make its own food |
| consumer | an organism that obtains energy by feeding on other organisms |
| decomposer | an organism that gets energy by breaking down biotic wastes and dead organisms and returns raw materials to the soil and water |
| food chain | a series of events in an ecosystem in which organisms transfer energy by eating and by being eaten |
| food web | the pattern of overlapping feeding relationships or food chains among the various organisms in an ecosystem |
| energy pyramid | a diagram that shows the amount of energy that moves from one feeding level to another in a food web |
