| A | B |
|---|
| niche | Special role of an organism in its environment |
| ecosystem | Groups of living things interacting with each other and the environment |
| community | All the different kinds of organisms in an ecosystem |
| water cycle | Continuous movement of water in an ecosystem |
| ecology | Study of living and nonliving parts of an ecosystem affect each other. |
| ecologist | Person who studies an ecosystem |
| food chain | Series of steps showing energy flow |
| food web | Includes all overlapping food chains in a community |
| predation | Act of one animal killing and eating another animal |
| nitrogen cycle | Continuous movement of nitrogen in an ecosystem |
| commensalism | Relationship in which one organism is helped and the other is not harmed |
| decomposer | A special consumer that gets energy by causing dead organisms to decay. |
| symbiosis | Relationship between two different species of organisms that live in close contact. |
| parasitism | A kind of symbiosis in which one organism is helped and the other is harmed. |
| mutualism | Relationship that benefits both species. |
