Nitrogen is a component of amino acids, proteins, and nucleic acids and often limits plant nutrient. Through the cycle, various forms of nitrogen are formed such as ammonium, nitrate, and nitrite. Plants use ammonium and nitrate, and various bacteria use

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• Nitrogen is a component of amino acids, proteins,
  and nucleic acids and often limits plant
  nutrient. Through the cycle, various forms of
  nitrogen are formed such as ammonium, nitrate,
  and nitrite. Plants use ammonium and nitrate, and
  various bacteria use nitrite. Animals can only
  use organic forms of nitrogen.
• Pesticides in the soil effects
  nitrification. Some herbicides temporarily
  interrupt nitrification. In other experiments,
  chemicals such as BHC (benzene hexachloride),
  aldrin, lindane, heptachlor, and DDD prevent
  nitrogen-fixing bacteria from forming the
  necessary root nodules of legumes. Such changes
  in the soil could alter metabolic activity and
  affect productivity. This means that harmful
  organisms that were once in check could rise to
  pest status.

Nitrogen Cycle
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Phosphorus Cycle

• Organisms need phosphorus as a constituent of
  nucleic acids, phospholipids, and ATP and other
  energy-storing molecules. Plants use phosphate to
  synthesize organic compounds

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Biological Magnification

• Biological Magnification is a process when
  certain substances like pesticides, move higher
  up in the food chain and work their into bodies
  of water where they are consumed by aquatic
  organisms such as fish, which are then eaten by a
  larger organisms. As the chemical substances move
  up the food chain they become more concentrated
  in tissues and internal organs.
• In Silent Spring, Rachel Carson describes
  different scenarios in which the humans want to
  get rid of another organism (usually an insect)
  that is causing an inconvenience. Since the
  pest isnt always the one hurt it still has the
  toxic chemicals inside it, causing anything that
  eats it to be poisoned. What then happens is it
  usually goes into the humans and we end up
  hurting ourselves.

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Bibliography

• Water Cycle
• http//www.metoffice.gov.uk/education/images/water
  _cycle.jpg
• Carbon Cycle
• http//io.uwinnipeg.ca/simmons/16cm05/1116/16ecos
  ys.htm
• Nitrogen Cycle
• http//www.uwsp.edu/geo/faculty/ritter/geog101/tex
  tbook/earth_system/nitrogen_cycle_EPA.jpg
• Phosphorus Cycle
• http//bioh.wikispaces.com/MoreElementalCycles?f
  print
• AP Edition Biology Seventh Edition
• -Neil A.Campbell and Jane B. Reece