Flashcards
carbon, water, nitrogen cycle
Cards in this deck (13)
- 1carbon cycle- co2 removed from air by plants and algae for photosynthesis (they release carbon to make carbohydrates, proteins and fats) - eaten and carbon moves up the food chain
- co2 returned into air when plants, algae and animals respire.
decomposers respire while they return mineral ions into soil
co2 is returned into the air when wood and fossil fuel are combusted (contain carbon from photosynthesis) - 2decompositionmeans habitats can be maintained for organisms that live there
(nutrients are returned into the soil) \ - 3water cyclesun's energy causes water to evaporate from sea and lakes forming water vapour
(also formed by transpiration)
- rises then condenses to form clouds
- returned to land by precipitation (runs into lakes and provides water for plants and animals)
- runs into seas and the cycle begins again - 4when does drough occurwhen there isnt enough precipitation
- in areas of drought we can harness the water cycle to produce potable water eg desalination - 5desalinationprocess by which we remove salt and other impurities from seawater to make it drinkable
performed by reverse osmosis (large scale) - gets rid of impurities in water - 6process of desalinationsalt water treated to remove solids before being fed at a high pressure into a vessel containing partially permeable membrane
-Pressure - causes water to move in the opposite direction to osmosis - from a higher salt concentration to a lower
- as water is FORCED through the membrane - salts are LEFT behind removing them from the water - 7nitrogen gas is very unreactive so it can't be used directly by plants and animalsNitrogen fixing bacteria present in root nodules legume plants convert nitrogen into nitrates that can be used for growth
- 8what else can convert nitrogen into nitrateslightning - energy is enough to make nitrogen react with oxygen in the air to give nitrates
- 9haber process converts hydrogen gas into ammoniaplants absorb nitrates through the roots by active transport
- 10nitrogen is often included in fertilisers to form ammonium nitratesprovides artificial way to make sure the plants gets nitrates required for growth without relying on external processes such as nitrogen fixing bacteria or lightening
- 11crops take nitrates from the soil as they growcrops are harvested and arent left to decompose so the nutrients aren't returned to the soil (overtime nitrogen content decreases leading to poor crop growth and deficiency diseases)
- 12ways to increase the amount of nitrates in the soil to help plants grow betterCROP ROTATION - different crops are grown each year in a cycle
(cyle includes nitrogen fixing crop eg peas or beans which helps put back nitrates in the soil for another crop to use the following year
FERTELISERS - spreading animal manure or compost on field recycles nutrients left in plants and animal waste (returns them to soil by decomposition) - 13disadvantages of fertilisersexpensive
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- GCSE Biology GCSE (paper 2) Flashcards on carbon, water, nitrogen cycle, created by Ellaine Wahome on 14/06/2022.
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- Ellaine Wahome
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