9 - Ecosystems - Cycles Flashcards
What are the 4 stages of the Water Cycle?
- Evaporation
- Transpiration
- Condensation
- Precipitation
What happens (briefly) at each stage of the water cycle?
E - Sun makes land water evaporate into vapour
T - Plant water also into vapour
C - Warm vapour carried up, cools/condenses into cloud
P - Water fall as precipitation; fresh land water
P - Water drains into sea, cycle again
Why is the Water Cycle so important?
- The water is constantly recycled
- If it wasn’t we’d run out quickly, meaning everything would die as everything needs water to live
How can thermal desalination be used to create potable water?
- Desalination removes salts from salt water (like sea)
- One method is thermal desalination:
- Salt water is boiled in a large vessel till it evaporates
- Steam rises, salts stay at the bottom
- Steam travels down a pipe … cools & condenses into pure water
How is reverse osmosis used in desalination?
- Osmosis here moves water from a lower salt conc to higher salt conc
- Reverse osmosis is the opposite & is used to rid impurities in water:
- Salt water treated to remove solids, then fed at high pressure to a vessel containing partially permeable membrane
- Pressure makes water move in opposite direction to osmosis - high to low
- Salts left behind as water forced through
What is a drought?
- Drougts occur when there isn’t enough precipitation
- Causes issues as we rely on precipitation for fresh water for drinking
- However, alternative methods exist for making potable water, like desalination
How can farmers increase the amount of nitrates in soil with crop rotation?
- Crops take up nitrates from the soil to grow, meaning overtime nitrogen content in soil decreases
- Instead of growing the same crop in a field year after year, different crops are grown in a cycle
- Cycle usually includes a nitrogen fixing crop to return nitrates to the soil for another plant to use next year
How can farmers increase the amount of nitrates in soil with fertilisers?
- Spreading animal waste/compost recycles the nutrients left in that waste & returns to the soil through decomposition
- Artificial fertiliers can also be used, though expensive and can cause environment issues
What are the 4 different types of bacteria involved in the nitrogen cycle?
- Decomposers
- Nitrifying Bacteria
- Nitrogen-Fixing Bacteria
- Denitrifying Bacteria
What is the role of Decomposers in the Nitrogen Cycle?
Decompose protein & urea, turns into ammonia
- Ammonia forms ammonia ions which plants can use
What is the role of Nitrifying bacteria in the nitrogen cycle?
Turns ammonia in decaying matter into nitrItes and then nitrAtes
- Diff species of nitrifying bacteria are responsible for making nitrites/nitrates
A ) Explain the importance of decomposition in the carbon cycle B ) What are the 4 organic compounds in the processes involved
A ) - Done by microorganisms which require oxygen & produce CO2 gas, H2O and lots of thermal energy
B ) Consumers, Green Plants, Dead Organisms, Fossil Fuels
Why are
A ) Consumers
B ) Green Plants
important to the carbon cycle?
A ) Respiration returns CO2 to the atmosphere or ait which is dissolved in water, mainly oceans. Increases CO2
B ) Feeds consumers, does photosynthesis which removes CO2 & respiration which returns CO2
How are
A ) Dead Organisms
B ) Fossil Fuels
involved in the carbon cycle?
A ) They fossilise, storing CO2 for a long time. During decay & decomp, CO2 is released as microorganisms respire
B ) Come from fossilisation of dead animals. Combustion & burning them releases CO2
What is the role of Nitrogen-Fixing bacteria in the nitrogen cycle?
Turn atmospheric nitrogen into ammonia, which forms ammonia ions
What is the role of Denitrifying bacteria in the nitrogen cycle?
Turns nitrates back into nitrogen gas; has no benifit to living things
- Denitrifying bacteria often found in waterlogged soils
