| A | B |
|---|
| ecology | the study of interactions among organisms and between organisms and their environment |
| biosphere | the part of Earth in which life exists inlcuding air, land and water |
| abiotic factors | a physical or nonliving "thing" that makes up part of an organism |
| population | all the organisms of a species that live in a defined area |
| community | all the populations that live together in a defined area |
| ecosystem | collection of all the organisms that live in a particular place together with their nonliving environment |
| habitat | the area where an organism lives including the biotic and abiotic factors |
| climate | average year after year environmental conditions in a particular region |
| rain shadow | a condition in which the majority of precipitation falls on one side of a mountain range leaving the other side dry |
| biome | group of ecosystems that have the same climate and distinctive plants and animals |
| niche | the combination of an organisms habitat and its role in its habitat |
| heterotroph | organisms that obtain energy from the food it consumes |
| producers or autotroph | organism that captures energy from the sun or inorganic compounds |
| consumers | organisms that rely on other organisms for its food |
| food chain | series of steps in an ecosystem in which organisms transfer energy by eating or being eaten |
| food web | network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem |
| trophic level | a step in a food chain or web |
| herbivore | organism that obtains energy by eating plants |
| carnivore | organism that obtains energy by eating animals |
| omnivore | organism that obtains energy by eating plants and animals |
| scavenger or decomposer | organism that obtains energy by eating dead matter |
| biological magnification | increasing concentration of a harmful substance at higher trophic levls in a food chain or web |
| biomass | total amount of living tissue within a given trophic level |
| ecological pyramid | diagram that shows the relative amounts of energy of matter within each trophic level in a food chain or web |
| fossil fuel | energy rich compound formed from decayed plant matter |
| nitrogen cycle | the cycle that follows the flow of nitrogen in the environment |
| water cycle | the cycle that follows the flow of water in the environment |
| nitrogen fixation | the process of converting nitrogen gas to ammonia (a liquid compound containing nitrogen) |
| renewable resource | a substance that can regenerate quickly or is replacable |
| nonrenewable resources | a substance that cannot regenerate quickly and is not replacable |
| greenhouse effect | natural situation in which heat is retained in the Earth's atmosphere by various gasses including carbon dioxide and methane |
| global warming | increase in the average temperature of the Earth |
| biotic factors | living influence on organisms within an ecosystem |
