| A | B |
|---|
| Biosphere | The part of Earth that supports life |
| Ecosystem | All of the living organisms in an area, as well as the nonliving parts of that environment |
| Ecology | The study of interactions that occur among organisms and their environments |
| Population | All organisms of the same species that live in an area at the same time |
| Community | All of the populations of all species living in an ecosystem |
| Habitat | The place in which an organism lives |
| Limiting factor | Anything that restricts the number of individuals in a population |
| Carrying capacity | The largest number of individuals of one species that an ecosystem can support over time |
| Producer | Organisms that use an outside energy source like the Sun to make energy-rich molecules |
| Consumer | Organisms that cannot make their own energy-rich molecules |
| Symbiosis | Any close relationship between 2 species |
| Mutualism | A symbiotic relationship in which both species benefit |
| Commensalism | A symbiotic relationship in which one organism benefits and the other is not affected |
| Parasitism | A symbiotic relationship in which one organism benefits but the other is harmed |
| Niche | An organism's role in its environment: how it obtains food and shelter, finds a mate, cares for its young, and avoids danger |
