| A | B |
| ecology | the study of the relationships and interactions of living things with one another and with their environment |
| ecosystem | a unit consisting of all the living and nonliving things in a given area that interact with one another |
| community | the living part of an ecosystem |
| population | a group of organisms of the same species living together in the same area |
| habitat | the place in which an organism lives and obtains the resources it needs to survive |
| producer | an organism that is able to make its own food by using a source of energy to turn simple raw materials into food |
| decomposer | an organism that breaks down the bodies of dead organisms into simpler substances |
| food chain | a representation of a series of events in which food energy and matter are transferred from one organism to another |
| food web | a diagram that consists of many overlapping food chains |
| herbivores | organisms that feed on plants |
| carnivores | organisms that feed on meat |
| omnivores | organisms that eat both plants and animals |