Nitrogen Cycle Notes
Nitrogen Cycle Diagram:
Why is nitrogen important for all living things?
Nitrogen Cycle Animation
1. Plants and animals __________________ _______________ pure
nitrogen gas, N2. It must first be ___________________ into a usable
form.
2. ______________________ can fix N2 allowing nitrogen to combine
with oxygen to form NO-3.
3. NO-3 enters the ___________ and is ___________________ into plants
through the roots. The plant then uses the nitrogen to form
other compounds (N*).
4. N2 can enter the ____________.
5. Some plants have special ______________ ____________________, like
the soybean plant. _________________________ in the root nodules
fix N2, allowing nitrogen to form other compounds (N*). The
plant can now use the nitrogen.
What are some ways that human activity impacts the Nitrogen
Cycle?
6. ______________________ in the _____________ fix N2, allowing nitrogen
to form other compounds (N*). Plants can now
_____________________ and use the nitrogen.
7. Animals, like the vole, ____________ the plant to get
_______________________ they can use.
8. As organic matter _________________________, the nitrogen
compounds return to the soil.
9. Other _______________________ in the soil break apart the
_________________________ compounds, allowing nitrogen
______________ (N2) to form and return to the air.
Describe three different roles that bacteria play in the Nitrogen
Cycle.