Biology 1 edexcel

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ft.xo
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#1
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#1
can someone please break down the nitrogen and carbon cycle for me please? and any predictions for what will be coming up in this years B1 paper for edexcel?
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ClandestineMoon
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#2
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Carbon cycle:
First I'd look at the Causes:
*Burning of fossil fuels
*Respiration of organisms
*Organisms that eat plants transfer carbon.
*Chalk dissolves when exposed to slightly acidic rain. This releases more carbon in the atmosphere.

Then I'd look at how it is reduced out:
*plants absorb carbon dioxide. Enables their cells to produce sugars from the process of photosynthesis. Sugars form lipids (fats and oils)

The main 2 process of transferring carbon are RESPIRATION and PHOTOSYNTHESIS.



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ClandestineMoon
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#3
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Nitrogen cycle:
*Plants and animals can't absorb nitrogen as a gas. Therefore, they need to be in the form of nitrates.
*2 kinds of bacteria who change nitrogen gas into nitrates.
*1, nitrogen fixing bacteria, found in root nodules in leguminous plants. They convert (fix) nitrogen gas into nitrates for the plant. (Mutualistic relationship)
*2 nitrifying bacteria, converts ammonia from decaying plants and other waste into nitrates. The nitrates are then absorbed by the plants.

*Animals obtain nitrates from eating plants. This transfers nitrogen from the plant to the animal. This transfer would carry on as the animals eat other animals, still transferring the nitrogen.

* lightning can break apart nitrogen molecules. The nitrogen molecules which are broken then react with the oxygen in the atmosphere. This forms nitrogen oxide. Which then dissolves in rain drops.

*The nitrates which aren't absorbed by plants are release back into the atmosphere. This is done by DE-NITRIFYING BACTERIA. The bacteria converts nitrates back into nitrogen gas which is then release back into the atmosphere.

Hope this helps. 😊
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