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Biological Cycles
Water Cycle: movement of water from the
atmosphere to the Earth and back to the
atmosphere.
Condensation: when a gas is changed to a liquid
when cooled.
Precipitation: water falling to the ground in the
form of rain, snow, hail, or sleet.
Evaporation: when a liquid is changed to a gas
when heated.
Carbon Cycle: movement of carbon through the
environment.
Oxygen Cycle: movement of oxygen through the
environment.
Nitrogen Cycle: the movement of nitrogen through
the biosphere.
- Nitrogen is essential to building proteins.
- 78% of the atmosphere is nitrogen.
- Nitrogen is found in the waste of animals and
dead and decaying organisms.
- However, most of the nitrogen in nature isn't able
to be used by organisms, so it must be converted to
another form.
Nitrogen fixation: the process of changing free
nitrogen in the atmosphere to nitrogen compounds that
can be used by living things.
Done by nitrifying bacteria which live on the
roots of plants.
Denitrification: the process of breaking down
nitrogen compounds into free nitrogen. Returns free
nitrogen to the air.
Done by denitrifying bacteria.
Eutriphication: When excess nutrients (phosphates
and nitrates) enter the river or lake, they are
immediately taken up by algae and plants.
When there is a lot, the algae and plants have
excessive growth.
The plants or algae die, bacteria numbers escalate
to break down the algae and plants.
The bacteria consume the available oxygen and
this results in the death of other organisms.
Limiting factor: anything that is in short supply that
is limiting an organisms growth.