1. 2.9 Nitrogen Cycle Class Notes

2. The Nitrogen Cycle All organisms need nitrogen.

3. Nitrogen Cycle Nitrogen gas makes up 80% of the atmosphere. However, plants and animals cannot use this form of nitrogen.

4. Nitrogen Cycle - B A A B B C C D D E E Bacteria that live on the roots of some plants take in the nitrogen gas and use nitrogen fixation to convert the gas into usable nitrogen.

5. Nitrogen Cycle - C A A B B C C D D E E Plants absorb nitrogen from the soil.

6. Nitrogen Cycle - D A A B B C C D D E E Animals get their nitrogen from eating plants and other animals.

7. Nitrogen Cycle - E A A B B C C D D E E When plants and animals die, their nitrogen goes back into the soil.

8. GP1 How does the tree in this diagram get nitrogen?

9. GP2 Can the deer in the picture get nitrogen gas from the air?

10. GP3 Where can it get nitrogen?

11. GP4 What happens during nitrogen fixation?

12. GP5 What happens to the nitrogen in plants and animals after they die?