| A | B |
|---|
| environmental science | the study of how humans interact with the environment |
| natural resource | any natural substance that living things use |
| nonrenewable resources | resources that cannot be replaced |
| renewable resources | resources that are continually being replaced |
| biosphere | the thin layer of life around the Earth |
| sustainable world | a world in which human populations can continue to exist indefinately with a high standard of living and health |
| hypothesis | a scientist's prediction of what the correct answer will be, based on what he or she has already learned |
| experiment | when a hypothesis is tested under controlled conditions |
| biotic factors | the living parts of an ecosystem |
| abiotic factors | the nonliving parts of the ecosystem |
| organism | one individual, living thing |
| species | a group of organisms that are able to reproduce together, and that share common genes and therefore resemble each other |
| population | a group of individuals of the same species living in a particular place |
| community | a group of interacting populations of different species |
| niche | an organism's way of life |
| habitat | the actual place an organism lives |
| producer | an organism that makes its own food |
| consumer | an organism that gets its energy from eating other organisms |
| herbivores | consumers that eat only producers |
| carnivores | consumers that eat only other consumers |
| omnivores | consumers that eat both producers and other consumers |
| decomposers | consumers that get their food by breaking down dead organisms |
| cellular respiration | the process of breaking down food to yeild energy |
| pioneers | the first organisms to colonize any newly available area and start the process of succession |
| succession | a regular pattern of changes over time in the types of species in a community |
