| A | B |
|---|
| ecosystem | all the living and nonliving things in an area |
| habitat | the place where an organism lives that provides it with the things it needs |
| biotic factor | a living thing |
| abiotic factor | a nonliving thing |
| species | similar organisms that can reproduce and have fertile offspring |
| population | all the members of one population in an area |
| community | all the living things in a area |
| ecology | the study of ecosystems and the interactions in them |
| birth rate | the number of births in a population |
| death rate | the number of deaths in a population |
| immigration | moving into a population |
| emigration | moving out of a population |
| limiting factor | any factor that stops a population from growing |
| carrying capacity | the number of organisms an area can support |
| natural selection | process by which individuals that are better adapted to the environment are more likely to survive and reproduce |
| adaptation | the characteristics and behavior that help an organism to live successfully |
| niche | an organisms role or job in an ecosystem |
| predation | an interaction in which one organism kills and eats another |
| prey | an organism that is eaten |
| symbiosis | an interactions in which at least one organism is benefited |
| mutualism | a relationship in which both organisms benefit |
| parasitism | a relationship in which one organism benefits but the other organism is harmed |
| commensalism | a relationship in which one organism benefits and the other is neither helped nor harmed |
| parasite | an organism that lives in or on another and harms it |
| host | the organism that a host used for energy |
