Download Nutrient Cycle Webquest

The Nitrogen Cycle
Nitrogen is an essential part of proteins and DNA. Like carbon, nitrogen must be recycled
continuously. Go to the following website or search on your own to learn how this happens:
http://www.windows2universe.org/earth/Life/nitrogen_cycle.html
1. Where is most nitrogen in the biosphere located?
2. This nitrogen is not in a useable form. Plants and animals cannot simply absorb nitrogen
from the atmosphere. Therefore, it must be _____________________ , which means
________________________________.
3. There are two ways that nitrogen can be removed from the atmosphere:
a)
b)
4. What happens to nitrogen inside of a plant?
5. How does the nitrogen get to carnivores?
6. What happens to the nitrogen when organisms die?
7. What is the name of the process which returns nitrogen to the atmosphere?
8. Go to the following site and place a number next
to the steps involved in the nitrogen cycle:
http://ridge.icu.ac.jp/gen-ed/ecosystemjpgs/nitrogen-cycle.jpg
o nitrogen-fixation – (nitrogen in atmosphere converted
to ammonia by lightning or nitrogen-fixing bacteria)
_____
o nitrification (ammonia converted to nitrates by
nitrifying bacteria)_______
o assimilation (plants absorb nitrates, incorporate into
proteins. Nitrogen in now in the food chain) _____
o ammonification (dead plants/animals converted to
ammonia by ammonifying bacteria) _____
o denitrification (some nitrates are returned to atmosphere by denitrifying bacteria) _______
9. What type of organism do you notice is essential in nearly every stop of the nitrogen
cycle?
10.Where do plants get their nitrogen from?
Go to the following link and read the story.
http://www.windows2universe.org/earth/climate/nitrogen_changes.html
11. What are the ways that humans can effect the nitrogen cycle? What could we do to
lessen our impact.
Websites
http://nortonbooks.com/college/biology/animations/ch38a02.html
http://www.physicalgeography.net/fundamentals/9s.html
http://www.neuse.ncsu.edu/nitrogen/
Questions
How is nitrogen important in our lives?
Why are nitrogen-fixing bacteria contributions to the nitrogen cycle so important?
Nitrogen gas makes up ____________________________ of the air we breathe.
Nitrogen __________________________ converts ____________________________ to
_____________________________ for organisms to use.
Another useable form of nitrogen, NH4 + can be converted to
_________________________ by ___________________________ for organisms to
use.
Plants use both __________________________ and ________________________ to
incorporate nitrogen into DNA, protein, and other molecules.
Explain how animals get their needed amounts of nitrogen.
Explain how nitrogen cycles through the land and ocean ecosystems.
How does the human impact of fertilizers impact the nitrogen cycle?