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Biology Quizlet #24
15 terms quater 4
Term | Definition |
---|---|
climax community | A stable, mature community that undergoes little or no change in species over time |
keystone species | A species that influences the survival of many other species in an ecosystem |
indicator species | Species that serve as early warnings that a community or ecosystem is being degraded. |
nutrient | chemical substance that an organism needs to sustain life |
biogeochemical cycle | process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another |
nitrogen fixation | process of converting nitrogen gas into nitrogen compounds that plants can absorb and use |
eutrophication | A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria. |
atmosphere | The layer of gases surrounding Earth |
geosphere | the solid part of the earth consisting of the crust and outer mantle |
hydrosphere | All the water at and near the surface of the earth, 97% of which is in oceans |
ecological succession | the predictable replacement of one group of species by another group of species over time |
primary succession | An ecological succession that begins in an area where no biotic community previously existed |
secondary succession | Succession following a disturbance that destroys a community without destroying the soil |
pioneer species | First species to populate an area during primary succession |
biosphere | part of Earth in which life exists including land, water, and air or atmosphere |