Download Plants cannot use nitrogen in a gas form. Through a series of steps

Nitrogen Cycle
Plants cannot use nitrogen in a gas form. Through a series of steps, nitrogen in the atmosphere is converted to
compounds that plants can use to build proteins and other important biomolecules
Using the diagram, fill in the blanks and answer the questions on the next page
N2
Nitrogen is a gas in the ________atmosphere_____________
NH3
Ammonia is converted from N2 by ____________bacteria__________________
NH4+
Ammonium is found in the _________soil________
NO3-
Nitrates are converted from NH4 by _______nitrifying bacteria_________
Producers use ____NO3- and NH4_______________
N2 is returned to the atmosphere by ____denitrifying bacteria___________________
Producers absorb the ammonium and nitrates from the soil and use them to build amino acids, proteins, and nucleic
acids.
Consumers that eat the producers thereby obtain their nitrogen in the form of organic molecules.
Decomposers release the nitrogen (as ammonium) from the wastes and decaying bodies of organisms, and the cycle
continues.
1. Plants use nitrogen in these 2 forms _______NO3-______________ ____NH4_________
2. Decomposers return ___________NH4+_____ to the soil
3. Denitrifying bacteria in the soil convert some ____NO3_____ back to ___N2_____ and release it into the atmosphere.
4. When the rabbit dies, his decaying body will be broken down and returned to the soil by
______________Decomposers________
5. What would be lost if nitrogen fixation (from nitrogen fixing bacteria) did not occur?
______there would be no ammonia and plants wouldn’t be able to use other
nitrogen.___________________
6. What would be lost if there were no nitrifying bacteria?
______there would be no NO3-____________________
7. Why are bacteria, worms and other decomposers important organisms in the nitrogen cycle and for all of life?
Because the plants can then get nitrogen they need and nitrifying bacteria break the Nh4 down to NO3.