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Biology Ch 18.4
Ch.18 vocab
Term | Definition |
---|---|
biogeochemical cycle | the circulation of substances through living organisms from or to the environment |
ground water | the water that is beneath the Earth's surface |
water cycle | the continuous movement of water between the atmosphere, the land, and the oceans |
transpiration | the process by which plants release water vapor into the air through stomata; also the release of water vapor into the air by other organisms |
carbon cycle | the movement of carbon from the nonliving environment into living things and back |
nitrogen cycle | the process in which nitrogen circulates among the air, soil, water, plants, and animals in an ecosystem |
nitrogen fixation | the process by which gaseous nitrogen is converted into ammonia, a compound that organisms can use to make amino acids and other nitrogen-containing organic molecules |
nitrogen-fixing bacteria | bacteria that convert atmospheric nitrogen into ammonia |
ammonification | the formation of ammonia compounds in the soil by the action of bacteria on decaying matter |
nitrification | the process by which nitrites and nitrates are produced by bacteria in the soil |
denitrification | the liberation of nitrogen from nitrogen-containing compounds by bacteria in the soil |
phosphorus cycle | the cyclic movement of phosphorus in different chemical forms from the environment to organisms and then back to the environment |