| A | B |
|---|
| biosphere | the part of Earth that supports life |
| community | all the populations in an ecosystem |
| habitat | the place in which an organism lives |
| ecosystem | all the organisms living in an area and the nonliving features of their environment |
| limiting factor | anything that restricts the number of individuals in a population |
| population | all the organisms in an ecosystem that belong to the same species |
| ecology | the study of interactions among organisms and their environment |
| carrying capacity | the largest number of individuals of one species that an ecosystem can support over time |
| consumer | organisms that cannot make their own energy-rich molecules |
| niche | how an organism survives, including its habitat, and how it obtains food and shelter |
| producer | organisms that use an outside energy source, such as the Sun, to make energy-rich molecules |
| symbiosis | any close relationship between species |
