| A | B |
| producer | An organism that can make its own food. |
| consumer | An organism that obtains energy by feeding on other organisms. |
| decomposer | An organism that breaks down large chemicals from dead organisms into small chemicals and returns important materials to the soil and water. |
| food web | The pattern of overlapping food chains in the ecosystems. |
| predator | A carnivore that hunts and kills other animals for food and has adaptations that help it capture the animals it preys upon. |
| prey | An animal that a predator feeds upon. |
| competition | The struggle between organisms for the limited resources in a habitat. |
| cooperation | Process of groups of organisms working or acting together for common or mutual benefit. |
| symbiotic relationship | A close relationship between two organisms in which at least one of the organisms benefit. |
| niche | An organism’s particular role in an ecosystem, or how it makes its living. |
| community | All the different populations that live together in an area. |
| population | All the members of one species in a particular area. |
| species | A group of similar organisms whose members can mate with one another and produce fertile offspring. |
| mutualism | A relationship between two species in which both species benefit and neither is harmed. |
| parasitism | A relationship in which one organism lives on or inside another and harm it. |
| parasite | A relationship in which one organism lives on or inside another and harm it. |
| host | An organism that provides a source of energy or a suitable environment for a virus or for another organism to live. |
| commensalism | A relationship between two species in which one species benefits and the other is neither helped nor harmed. |