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The Nitrogen Cycle Mrs. Harper Biology 3/28/18
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March 28, 2018 Begin working on Do Now
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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?
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Review: The Water Cycle
Condensation Precipitation Evaporation Transpiration
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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.
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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
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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
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Denitrification Denitrification- process by which bacteria converts nitrogen in the soil back into nitrogen gas and releases it into the atmosphere
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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
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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
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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
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Carbon-Oxygen Cycle Ms. Grizz Biology 1/28/16
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Nitrogen fixation Denitrification Atmospheric nitrogen
Nitrogen in the soil Nitrites Ammonia Nitrates
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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
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Cellular Respiration Cellular respiration- organisms take oxygen from the atmosphere to produce carbon dioxide Animals and some plants go through this process
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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
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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
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Reservoirs for Carbon Fossil Fuels (coal, petroleum, natural gas)
Forests Peat bogs Animal waste
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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
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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
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Review: Carbon-Oxygen Cycle
Cellular Respiration Decay of organisms Photosynthesis Burning of fossil fuels Carbon Dioxide
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Carbon-Oxygen Cycle Burning of fossil fuels
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