| A | B |
|---|
| ecology | study of interactions between organisms and their environment |
| biosphere | life-supporting portions of Earth including air, land, fresh & salt water |
| biotic factor | all living organisms inhabiting any of Earth's many different environments |
| abiotic factor | non-living parts of the environment such as air currents, temperature, soil, light, and moisture |
| population | interbreeding individuals of 1 species competing for food & mates living in same place & time |
| community | interacting populations in same environment; each organism depends on other organisms |
| ecosystem | populations in a community & abiotic factors with which they interact; ex. terrestrial and marine ecosystems |
| niche | role of species in community regarding food, space, & interactions with abiotic factors |
| habitat | collection of niches in which an organism lives its life |
| autotroph | organisms able to synthesize food using energy from sun or chemical compounds |
| heterotroph | organisms unable to make their own food; also called consumers |
| scavenger | animals that consume dead organisms and their refuse |
| decomposer | organisms that break down & use nutrients from dead & decaying organic matter |
| symbiosis | permanent, close associatioin between 2 or more organisms of different species |
| commensalism | symbiotic relationship where 1 species benefits, the other is neither harmed nor helped |
| mutualism | symbiotic relationship beneficial to both species |
| parasitism | symbiotic relationship in which one species benefits at the expense of the other |
| food chain | transfer of matter & energy through an ecosystem from autotrophs to heterotrophs & decomposers |
| trophic level | link represented by each organism in a food chain |
| food web | shows all the possible feeding relationships in a community at each trophic level |
