| A | B |
| Individual | single organism in an environment |
| Population | same kind living in the same environment |
| Community | all the poplulations of organisms living together in an environment |
| Ecosystem | community and its physical environment |
| habitat | place where it lives in an ecosystem |
| niche | role organism plays |
| producers | green plants |
| consumers | eat other organisms |
| food chain | how energy is passed through communities |
| decomposers | break down dead organisms |
| food web | relationship between different food chains |
| energy pyramids | shows amount of energy that is passed from one level of a food chain |
| competition | contest over resources |
| symbiosis | relationship between different kinds of organisms |
| learned behaviors | behaviors learned from the parents |
| instinct | behavior that is inherited from the parents |