| A | B |
| Adaptation | Any inherited characteristic that increases the chance of an organism surviving and producing offspring that will also reproduce |
| Stimulus | something in the environment that produces a response from an organism |
| Behavior | Any observable response to a stimulus |
| Interaction | The action or influence of organisms on each other |
| Symbiosis | A close relationship between two different species that live with or near each other. |
| Parasitism | A symbiotic relationship where the parasite lives in or on the host and harms it |
| Commensalism | A symbiotic relationship where one organism benefits and one is not affected |
| Mutualism | A symbiotic relationship where both organisms benefit |