1. The Nitrogen Cycle
Mrs. Harper
Biology
3/28/18

2. March 28, 2018
Begin working on Do Now

3. Do Now 3/28/18 What is a reservoir? Name some reservoirs for water.
Define precipitation.
Define condensation.
Define evaporation.
Define transpiration.
What are some human activities that effect the water cycle?

4. Review: The Water Cycle
Condensation
Precipitation
Evaporation
Transpiration

5. The Nitrogen Cycle
The continuous movement of nitrogen through each of Earth’s systems is the nitrogen cycle.
Nitrogen is a key element in organisms
Nitrogen makes up 78% of the Earth’s atmosphere.

6. Nitrogen Fixation
Most living things cannot use nitrogen directly from the atmosphere
Nitrogen Fixation- bacteria in the soil converts nitrogen gas into substances that living things can use
These substances include ammonia, nitrates and nitrites

7. Nitrification (Nitrogen in Soil)
Plants take in these nitrogen compounds and use them to make proteins
Animals eat these plants to get the protein
When organisms die, decomposers break down their remains and return nitrogen to the soil

8. Denitrification
Denitrification- process by which bacteria converts nitrogen in the soil back into nitrogen gas and releases it into the atmosphere

9. Effects of Nitrogen Cycle Changes
Overplanting uses up nitrogen in soil and makes soil barren.
Land development and clear-cutting of forests can expose soil to erosion.
Wind and running water carry away nutrient-rich soil

10. Effects of Nitrogen Cycle Changes
Artificial fertilizers put excess nitrogen in water which causes an overgrowth of algae
When algae die, they use up oxygen
This lack of oxygen kills organisms that live in that ecosystem

11. RAPID REVIEW What are the three major stages of the nitrogen cycle?
What percent of the Earth’s atmosphere is nitrogen?
What happens in nitrogen fixation?
4. What is one effect of changes in the nitrogen cycle?
Nitrogen fixation, nitrification, denitrification
78%
Bacteria converts nitrogen gas into usable substances
Overplanting uses up nitrogen and makes soil barren

13. Carbon-Oxygen Cycle
Ms. Grizz
Biology
1/28/16

14. Nitrogen fixation Denitrification Atmospheric nitrogen
Nitrogen in the soil
Nitrites
Ammonia
Nitrates

15. The Carbon-Oxygen Cycle
The continuous movement of carbon and oxygen through each of Earth’s systems is the Carbon-Oxygen cycle.
Carbon and oxygen are vital to living things.
Oxygen makes up 21% of the Earth’s atmosphere.
Carbon dioxide makes up less than 1% of the atmosphere

16. Cellular Respiration
Cellular respiration- organisms take oxygen from the atmosphere to produce carbon dioxide
Animals and some plants go through this process

17. Decay/Burning of Organic Matter
Death and decay of living things forms fossil fuels, which are huge reservoirs of carbon
Burning of fossil fuels releases massive amounts of carbon dioxide into the atmosphere

18. Photosynthesis
Photosynthesis- plants combine water and carbon dioxide to produce oxygen
This oxygen is released into the atmosphere, as well as used by living organisms
Plants also remove carbon dioxide from the atmosphere

19. Reservoirs for Carbon Fossil Fuels (coal, petroleum, natural gas)
Forests
Peat bogs
Animal waste

20. Effects of Carbon Cycle Changes
Population growth and land development have led to increased deforestation and the burning of fossil fuels
These processes have greatly increased carbon dioxide levels in the atmosphere
This causes an increase in temperature which is the reason for Global Warming

21. Rapid Review
1. What percent of the atmosphere is carbon? What percent is oxygen?
2. What are some reservoirs for carbon?
3. Explain photosynthesis.
4. What are some effects of changes in the carbon cycle?
21% Oxygen, About 1% Carbon Dioxide
Fossil Fuels, Peat Bogs, Waste
Plants combine water and CO2 to produce oxygen
Global Warming

22. Review: Carbon-Oxygen Cycle
Cellular Respiration
Decay of organisms
Photosynthesis
Burning of fossil fuels
Carbon Dioxide

23. Carbon-Oxygen Cycle
Burning of fossil fuels