| Term | Definition |
| producer | an organism that makes its own food.( Ex. a plant) |
| consumer | An organisms in a community that must eat to get the energy it needs to live. |
| herbivore | An organism that gets its energy by eating plants. (Ex. a cow) |
| carnivore | An organism that gets its energy by eating other animals. Ex a lion |
| omnivore | An organism that gets its energy by eating both animals and plants. (ex. bear) |
| decomposer | An organism that breaks down dead organism and absorbs its nutrients. (Ex: mushrooms and bacteria) |
| scavenger | An organism that eats dead animals. ( Ex. vulture) |
| parasite | An organism that lives in or on a living animal feeding off it. (Ex: flea) |
| predator | An animal that hunts, catches, and eats another animal. |
| prey | An animal that is hunted, caught, and eaten by another animal. |
| competition | Contest among organisms for the limited resources of an ecosystem. |
| food chain | The path of energy from one organism to another in an ecosystem. |
| food web | The overlapping food chains with different pathways for the food energy to flow in an ecosystem. |
| extinct | Plant and animal life which is no longer in existence. |
| endangered | Populations of species that have reduced so much that they are in danger of becoming extinct. |
| primary consumer | An organism that eats producers. |
| secondary consumer | An organism that eats primary consumers. |
| primary producers | Autotrophs/plant s supports all others in the ecosystem. |
| tertiary consumers | Organisms in the fourth trophic level which obtain their energy by eating secondary consumers. Plant (primary producer) .> grasshopper (primary) > mouse (secondary) > hawk (tertiary) |