essential elements describe the ________ of essential elements from the ______________ through living organisms and _______ into the environment. Biogeochemical Cycles

_____________________ Cycle

Hydrological Cycle Hydrological Cycle (___________ cycle) 1. Reservoir – oceans, _______ (as water vapor), groundwater, lakes and glaciers; evaporation, wind and precipitation (rain) move water from oceans to land 2. Assimilation – plants __________ water from the ground, animals drink water or eat other organisms which are composed mostly of water 3. Release – plants ___________, animals breathe and _________ liquid wastes

_______________ Cycle

Carbon Cycle Carbon Cycle (carbon is required for building __________________ compounds) 1. Reservoir – _______________ (as CO 2 ), ____________ fuels (oil, coal), durable organic materials (for example: _____________). 2. Assimilation – plants use CO 2 in ________________; animals consume plants. 3. Release – plants and animals release CO 2 through _____________ and decomposition; CO 2 is released as wood and fossil fuels are _________.

________________ Cycle

Nitrogen Cycle Nitrogen Cycle (Nitrogen is required for the manufacture of amino acids and nucleic acids) 1. Reservoir – ______________ (as N 2 ); soil (as NH 4 + or ammonium, NH 3 or ammonia, N0 2 - or nitrite, N0 3 - or nitrate

2. Assimilation – plants ____________ nitrogen as either NH 4 + or as N0 3 -, animals obtain nitrogen by eating plants and other animals. The stages in the assimilation of nitrogen are as follows: Nitrogen Fixation: N 2 to NH 4 + by nitrogen- fixing ________________ (prokaryotes in the soil and root nodules), N 2 to N0 3 - by ______________ and UV radiation. Nitrification: NH 4 + to N0 2 - and N0 2 - to N0 3 - by various _______________ bacteria. Nitrogen Cycle

3. Release – ________________ bacteria convert N0 3 - back to N 2 (denitrification); detrivorous bacteria convert organic compounds back to NH 4 + (ammonification); animals _____________ NH 4 + (or NH 3 ) urea, or uric acid. Nitrogen Cycle

_______________________ Cycle

Phosphorus Cycle Phosphorus Cycle (Required for the manufacture of _______ and all _____________ acids) 1. Reservoir – ______________ transfers phosphorus to water and soil; sediments and rocks that accumulate on ocean floors return to the surface as a result of _____________ by geological processes 2. Assimilation – plants absorb inorganic PO 4 3- (phosphate) from __________; animals obtain organic phosphorus when they ________ plants and other animals 3. Release – plants and animals release phosphorus when they ___________; animals excrete phosphorus in their waste products

Biogeochemical cycles of other minerals, such as calcium and magnesium, are ___________ to the phosphorus cycle.