| A | B |
|---|
| environmental science | the study of how humans interact with the environment. |
| environment | everything that surrounds us. |
| natural resource | any natural substance that living things use. |
| nonrenewable resource | sources that cannot be replaced. |
| renewable resource | resources that are continually being replaced, even as they are being used. |
| biosphere | the thin layer of life around the earth. |
| developed countries | highly industrialized countries, whose citizens have high average incomes. |
| population crisis | the number of people growing too quickly for the earth to support. |
| consumption crisis | people using up, wasting, or polluting natural resources faster than they can be renewed, replaced, or cleaned up. |
| ecology | the study of how living things are related to each other-how they interact and depend on each other. |
| ecosystem | all the different organisms living in a certain area, along with their physical environment. |
| biotic factors | the living parts of an ecosystem-animals, plants, and microorganisms. |
| abiotic factors | 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 eachother. |
| community | a group of interacting populations of different species. |
| predation | one organism kills and eats another organism. |
| competition | a relationship between species in which they attempt to use the same limited resources. |
| paratism | organisms that live in or on another organism and feed on it without immediately killing it. |
| mutualism | a cooperative partnership between two species. |
| commensalism | a relationship in which one species benefits and the other is neither harmed nor helped. |
| food chain | a sequence in which energy is transferred from one organism to the next as each organism eats another. |
| trophic level | each step in the transfer of energy through an ecosystem. |
| water cycle | when water moves between the atmosphere and the earth. |
| succession | a regular pattern of changes over time in the types of species in a community. |
