| A | B |
|---|
| ecosystem | the interaction of groups of living things with each other and with the environment |
| water cycle | the continuous movement of water in an ecosystem |
| carbon dioxide-oxygen cycle | the continuous exchange of carbon dioxide and oxygen among the producers, consumers, and the atmosphere |
| mutualism | a kind of symbiosis that helps both species |
| commensalism | a kind of symbiosis in which one species is helped and the other is neither helped nor harmed |
| parasitism | a kind of symbiosis in which one organism is helped and the other is harmed |
| producers | organism that uses the sun's energy to make food through photosynthesis |
| consumers | organism that must use plants or other animals for food |
| decomposers | consumers that get energy by causing dead organisms to decay |
| population | a group of organisms in a community that are all the same species |
| host | organism in or on which a parasite lives |
| predator | an animal that kills other animals for food |
| parasite | organism that lives in or on another organism and gets its food from the host |
| prey | an animal killed and eaten by a predator |
| ecology | the study of how living and nonliving parts of an ecosystem affect each other |
