| A | B |
|---|
| organism | living thing |
| biotic factor | living, or once living thing(s) |
| species | group of organisms that can mate with each other and produce offspring that can also mate and reproduce |
| community | all the different populations that live together in an area |
| ecology | the study of how organisms interact with each other and their environment |
| habitat | an environment that provides the things an organism needs to live, grow, and reproduce |
| abiotic factor | nonliving thing(s) |
| population | all the members of one species living in a particular area |
| ecosystem | a community of organisms that live in a particular area, along with their nonliving environment |
| birth rate | number of births per 1,000 individuals for a given time period |
| death rate | number of deaths per 1,000 individuals for a given time period |
| immigration | moving into a population |
| emigration | leaving a population |
| population density | the number of individuals in an area of a specific size |
| limiting factor | an environmental factor that causes a population to stop growing or decrease in size |
| carrying capacity | the largest population that an area can support |
| natural selection | a characteristic that makes an individual better suited to a specific environment through a process |
| niche | the role of an organism in its habitat |
| adaptation | the behaviors and physical characteristics that allow organisms to live successfully in their environment |
| competition | the struggle between organisms to survive as they attempt to use the same limited resources |
| predation | an interaction in which one organims kills another for food or nutrients |
| predator | the organism that does the killing |
| prey | the organism that is killed |
| symbiosis | any relationship in which two species live closely together and at least one of the species benefits |
| mutualism | a relationship in which both species benefit |
| commensalism | a relationship in which one species benefits and the other species is neither helped nor harmed |
| parasitism | a relationship that involves one organism living with, on, or inside another organism and harming it |
| parasite | the organism that benefits for parasitism |
| host | the organism it lives on or in |
| succession | the series of predictable changes that occur in a community over time |
| primary succession | the series of changes that occur in an area where no soil or organisms exist |
| pioneer species | the first species to populate an area |
| secondary succession | the series of changes that occur in an area where the ecosystem has been disturbed, but where soil and organisms still exist |
