| A | B |
|---|
| Population | A population is a group of individuals of a single species that occupy the same geographic area |
| Ecology | Ecology is the study of the interactions of organisms with their environments at the organismal, population, community, and ecosystem levels. |
| Community | A community is a group of populations that occupy the same geographic area |
| Biosphere | The biosphere is the global ecosystem -- the sum of all ecosystems on Earth |
| Abiotic factors or components of an ecosystem | Abiotic factors of an ecosystem are those nonliving things that determine the ecosystems structure and dynamics. Abiotic components include air, water, soil, soil nutrients, sunlight, temperature and wind. |
| Biotic factors or components of an ecosystem | Biotic components of an ecosystem are the living organisms making up the community or communities present. |
| Habitat | A habitat is the place where an organism lives or the environmental situation in which it lives. |
| Population density | The number of individuals of a species per unit area or volume. Example: 24 oak trees per square mile. |
| Consumer | An animal that obtains its food by eating plants or by eating animals that have eaten plants. |
| Producer | An organism that makes organic food molecules (sugars) by photosynthesis (using the sun's light) or chemosynthesis (using light from chemicals). |
| Solar energy | Energy obtained from the sun. |
| Species | A group whose members possess similar anatomical characteristics and can only breed with each other (interbreed). |
| Biome | A terrestrial (land) ecosystem distinguished mainly by its climate, and classified according to the main plants and animals that live there |
| Territory | An area that one or more individuals defend and from which other members of the same species are excluded. |
| Population ecology | The study of how members of a population interact with their environment. |
| Predator | An animal that kills and eats another organism, the prey. |
| Competition | Competition occurs as a population increases in density but resources like food or water are limited. |
