Natural Cycles

Natural Cycles

1. Nitrogen Cycle

   • Bacteria take in nitrogen and produce ammonia (NH3).
     • Other bacteria use this ammonia to produce nitrates and nitrites
       • The nitrates and nitrites are used by plants to make amino acids
         • Other organisms use the plant amino acids to make their own.
           • Decomposers convert the nitrogen into ammonia and return it to the soil. Bacteria returns nitrogen to the atmosphere.

2. Carbon and Oxygen Cycle

   • Carbon dioxide enters the atmosphere from respiration and combustion.
     • Carbon dioxide is absorbed by producers then they release oxygen.
       • Animals absorb carbon and oxygen and exhale carbon dioxide.
         • The dead organisms are eaten by decomposers. The carbon in their bodies is returned to the atmosphere as carbon dioxide. Some decomposed plants and animals may be available as fossil fuel for combustion.