Section 2.6 – The Nitrogen Cycle
1.
How much of the atmosphere is nitrogen? Is it in a usable form?
- Nitrogen gas makes up almost 79% of the Earth’s atmosphere
- It can on be used in living organisms in the form of nitrate ions NO3-
- Nitrogen in the atmosphere can be converted into nitrates through a process called nitrogen
fixation.
2. Why is nitrogen important to living organisms?
- Live depends on nitrogen because nitrogen atoms are required so cells can make protein.
- Nitrogen is also needed to make DNA.
3. What role does lightening have in the nitrogen cycle?
The energy from the lightning causes the nitrogen cause to react with nitrogen in the air producing
nitrates. The nitrates dissolve in rain or surface water, enter the soil, and then move into plants through
their roots.
4. What role do bacteria have in the nitrogen cycle?
- The bacteria provide the plant with useable nitrogen while the plant supplies the bacteria with
sugar which they need to make nitrates.
- These bacteria are called nitrogen fixing bacteria.
- The plant-bacteria combination usually makes more nitrates than they need so the excess nitrogen
moves into the soil.
5. What role do decomposers have in the nitrogen cycle?
Decomposers break down the nitrogen containing chemicals in the wastes and bodies into simpler
chemicals such as ammonia.
6. What is denitrification?
- Denitrification releases nitrogen gas back into the atmosphere.
- This process is carried out by bacteria that do not require oxygen.
7. Why are bogs and swamps usually low in nitrogen?
The oxygen content is very low and denitrification speeds up in a bog or a swamp, leaving very little
nitrogen in those areas.
8. Why is it a good idea to aerate you lawn?
Plants need nitrates in the soil and if the levels are low in your lawn you can aerate the lawn (increase
the amount of oxygen) to reduce denitrification.
9. Farmers often alternate crops that require a lot of nitrogen (corn) with crops that are less valuable but
require less nitrogen (alfalfa). Why would they do this?
The farmers need to alternate crops to keep the nitrate levels in the soil at an ideal level for growing the
more valuable crops.
Section 2.6 – The Nitrogen Cycle
1.
2.
3.
4.
5.
6.
7.
8.
9.
How much of the atmosphere is nitrogen? Is it in a usable form?
Why is nitrogen important to living organisms?
What role does lightening have in the nitrogen cycle?
What role do bacteria have in the nitrogen cycle?
What role do decomposers have in the nitrogen cycle?
What is denitrification?
Why are bogs and swamps usually low in nitrogen?
Why is it a good idea to aerate you lawn?
Farmers often alternate crops that require a lot of nitrogen (corn) with crops that are less valuable but
require less nitrogen (alfalfa). Why would they do this?
Section 2.6 – The Nitrogen Cycle
1.
2.
3.
4.
5.
6.
7.
8.
9.
How much of the atmosphere is nitrogen? Is it in a usable form?
Why is nitrogen important to living organisms?
What role does lightening have in the nitrogen cycle?
What role do bacteria have in the nitrogen cycle?
What role do decomposers have in the nitrogen cycle?
What is denitrification?
Why are bogs and swamps usually low in nitrogen?
Why is it a good idea to aerate you lawn?
Farmers often alternate crops that require a lot of nitrogen (corn) with crops that are less valuable but
require less nitrogen (alfalfa). Why would they do this?
Section 2.6 – The Nitrogen Cycle
1.
2.
3.
4.
5.
6.
7.
8.
9.
How much of the atmosphere is nitrogen? Is it in a usable form?
Why is nitrogen important to living organisms?
What role does lightening have in the nitrogen cycle?
What role do bacteria have in the nitrogen cycle?
What role do decomposers have in the nitrogen cycle?
What is denitrification?
Why are bogs and swamps usually low in nitrogen?
Why is it a good idea to aerate you lawn?
Farmers often alternate crops that require a lot of nitrogen (corn) with crops that are less valuable but
require less nitrogen (alfalfa). Why would they do this?