Nutrient Cycles
The biosphere is the part of the planet where life exists, including the air, soil and water. The three
main components of the biosphere are
1. __________________________ – layer of gases surrounding the Earth
2. __________________________ – the solid layer at the surface of the Earth
3. __________________________ – all the water on Earth
For organisms to grow they require nutrients from some part of the biosphere. Nutrients from food
and water
______________________________________________________________________________.
Nutrients are made of ____________________________ like oxygen, hydrogen, carbon and nitrogen.
Nutrients cycle from ___________________ to ____________________________ forms. Living plants
and animals are biotic reservoirs or
___________________________________________________________. When the plants and animals
die, the biotic molecules are _____________________________________________________________.
The abiotic nutrient reservoirs are ________________________________________________.
The water cycle moves the elements __________________________ and ________________________.
Two other nutrient cycles are the carbon cycle and the nitrogen cycle.
1) The Carbon Cycle
In the carbon cycle
_____________________________
________ is the only process to
change ______________________
carbon into
_______________________ carbon
for plants and animals.
_____________________________
____________,
____________________ and
__________________ all turn biotic
carbon into abiotic carbon dioxide.
The carbon reservoirs are the atmosphere and the oceans which
____________________________________. Also, living organisms have carbon in their
________________________, and carbon from dead plants and animals _________________________.
2) The Nitrogen Cycle
Abiotic nitrogen gas is part of air. Special __________________________________________ in the
roots of ____________________________can convert __________________________. Then
______________________ bacteria change ammonia to nitrites and nitrates. Nitrates are
_____________ by plant roots and used to______________________________. When animals eat
plants they absorb nitrates to make proteins. When dead plants and animals _________
______________________are broken down by decomposers to be reused. Different bacteria can also
convert nitrates back into atmospheric nitrogen.
Nutrient Cycles Worksheet
Name: _______________________
1.a)
Name and describe the process that takes carbon from the atmosphere and stores carbon in a biotic
form.
b)
Name and describe the two processes that take carbon from the biotic forms and release carbon in
an abiotic form.
c)
Name three foods you eat that are carbohydrates and provide your body with a lot of carbon.
2.a)
Describe the process that takes nitrogen from the atmosphere and stores nitrogen in the biotic
form of proteins.
b)
How is the nitrogen in proteins released to recycle?
c)
Is the same kind of bacteria doing both the nitrifying and denitrifying process? Guess.
d)
Name three foods you eat that contain a lot of nitrogen in proteins.
Bonus – Water Cycle questions
3.a)
How do plants get water into their cells?
b)
What are two ways animals get water into their bodies?
c)
Describe two ways that animals release water to go back into the atmosphere.
d)
How do plants release water to go back into the atmosphere