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.
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.