| A | B |
|---|
| natural selection | individuals whose unique characteristics are best suited for their environment tend to survive and produce offspring |
| adaptations | the behaviors and physical characteristics that allow organisms to live successfully in their environments |
| niche | the role of an organism in its habitat, or how it makes its living |
| competition | the struggle between organisms to survive as they attempt to use the same limited resource |
| predation | an interaction in which one organism kills another for food |
| predator | the organism that does the killing in a predation interaction |
| prey | the organism that is killed in the predation interaction |
| symbiosis | a close relationship between two species that benefits at least one of the species |
| mutualism | a relationship in which both species benefit |
| commensalism | a relationship in which one species benefits and the other is neither helped nor harmed |
| parasitism | involves one organism living on or inside another organism and harming it |
| parasite | the organism that benefits from parasitism |
| host | the organism that is harmed in the parasitism relationship |
| succession | a series of predictable changes that occur in a community over time |
| primary succession | the series of changes that occur where no soil or organisms exist |
| pioneer species | the first species to populate an area |
| secondary succession | a series of changes that occur in an area where the ecosystem has been disturbed, but where soil and organisms still exist |
