A2 quiz Flashcards
explain the water cycle
connects ecosystems
1) liquid water in lakes/ponds is turned into a gas through evaporation
2) water vapout in atmosphere condenses in clouds
3) Liquid water returns to the ground through precipation
4) Water re enters lakes/ponds/oceans through run offs
what makes water the universal solvent
water molecules are polar(different charges at each end) this results in a week attraction between molecules known as a hydrogen bond
this enables water to dissolve wide variety of substances
what biogeochemical cycling
porcess of transporting dissolved materials
movement of nutrients between biotic and abiotic factors
what allows water to remain liquid and how does it change states
hydrogen bonding allows water to remain liquid state across a lagre temp range
large amounts of energy are required to change state (high boiling point and low melting point point
explain water densisty
more dense as a liquid then a solid
most dense at 4 degrees celcius
water warms or cools gets less dense
when water cools hydrogen bonds losen causing solid water to have a lower densisty causing ice to float
what is cohesion in water
water molecules are polar so they are attracted to one other, this causes cohesion which is responsible for surface tension
what is adhesion in water
water molcules are attracted to molecules of other substances, porvides upward force counteracting the pull of gravity
what are some examples of carbon sinks and how is carbon relased from them
trees, fossil fuels deposists, oceans and lime stone rocks
carbon is realsed from reservoirs both quickly (forest fires) and slowing weathering)
What is the green house effect in water
when water is scarce plants respond by closing their stoma, this reduces transpiration meaning it cannot take in CO2 which slows photosynthesis
due to the greenhouse effect metabolic activites (cell resp and photo syntheis) slow and less CO2 is taken from the air
what is slow cycling in the carbon cycle
carbon accumulates and is stored in various reservoirs (carbon sinks) for long periods of time where is it unavaiable to organisms until realsed
what is weathering
wearing down or breaking of rocks
what are some human impacts on the carbon cycle (5)
hydrocarbon combustion (CO2 in atmosphere)
deforestation (removing carbon sinks)
human caused forest fires
agriculutre
acification of oceans (co2 in h20 aka carbonic acid
where is the carbon
in abotic enviroenments some carbon is in the form of CO2 is held in the atmosphere however majoirty dissolved in worlds oceans
although primary source for use by the biotic enviroenment is the atmosphere
what is carbon fixtation
carbon is captured from the atmpsphere through photosyntheis and is realsed through cell resp
how does carbon get realsed back into the atmpsphere
- remaining carbon in living organisms is returned to the atmosphere or to the water cycle when waste decays
- if this proccess is delayed and the bdoies become burried under large rocks it is possible to create fossil fuels
how is carbon found in aquatic ecosystems
carbon is incorporated into carbonate compounds which is used to form shells
this carbon can also be trapped in the form of sedimentary rocks
carbon trapped in carbonate rocks like limestones can be realesed by heat produced by volcanic activty, this heat breaks down the rock relasing CO2 in the atompshere
What are the proccess invovled in the carbon cycle (8)
- photosynthesis/ chemosyntheis aka carbon fixtation
celluar resp
death and decay or organisims
fossilaztion
burning fossil fuels
formation of carbonate compounds
sedimentation
volcanic heating of carbonate rocks
what is sedimentation
organic or inorganic carbon will settle to the bottom of the ocean or freshwater system creating sediemnts rich in carbon
why does nitrogen cycle and why is it important
most organisms cannot use atmospheric nitorgen (N2)
makes up 78% of earths atmosphere and is essiental compenet in our DNA
Explain the nitrogen cycle
- Ammonia (NH3 or NH4 is coverted into
- nitrites (NO2) then
- nitrates (NO3)
this can then be used by plants which are eaten by animals
what is denitrifcation
excess nitrates in the soil are converted back into atmosphereic nitrogen by a different set of bacteria
these bacteria are…
- anaerboic (O2 intolerant)
- live in the soil
-remove nitrates and nitrites and covert them into nitgrogen gas and nitruous oxide which returns to the atmosphere
this proccess will increase in rate if the soil is acidic or waste logged
what is nitorogen fixtation
invloves converting gaseous nitrogen into a form available to the biotic enviornemnet (ammounim or nitrates)
how does nitorgen fixtation happen
Lighting- causes reaction betwene nitrogen gas and oxygen in the air result is the formation of NO3 - ions which combine with water to enter the soil
Nitrogen fixing bacteria- bacteria fix nitroegn gas from the air prouding ammonia NH3 which becomes ammonium NH4
Nitrifying bacteria- convert NH4 into NO2 then NO3
these bacteria are found in the soil and root nodules on legumes, provides plants woth more then enough nitrogen
explain the relashionship between nitrogen fixing bacteria and plants
they are often associated with the roots of legume (bean plants) such as clover
bacteria convert nitorgen into ammounium for the plants and in returen plants prodvide bacteria with sugars
Atmospheric nitrogen fixtation:
lighting converts N2 into N03
nitrogen fixing bacteria:
convert N2 into NH4
nitrfying bacteria:
convert ammonium ions into nitrates NH4 into NO3
what is the formula for nitrites
NO2
formula for nitrates
NO3
why is phosphorus important and where is it found
essential nutrient (found in bones and teeth) but it is found in limmited quanities
does not cycle through the atmosphere but instead found in soil and water, often added ti crops as a fertilizer
how can aniamls and plants obtain phosphorus
animals- eating milk grains and meats
plants- can only use in form of phosphates which disolve in H2O
where is phosporus long/short cycle
Long cycle- invloving rocks and earth’s crust
short cycle- invloving living organisms
what are some proccess invloved in the phosporus cycle (8)
- geological uplift
-errosion/weathering
-decomposition
-ingestion
-aboorbiton
-leacing
-sedimentation
-run off
human impacts on the amount of phosporus
- detergents (used to conatain phosphates)
- agriculture (fertilizers)
- golf courses
- excess nutroents in lakes/ rivers - eutrophication aka algeal bloom
what are stromata lights
produced by cyanobacteria, are the houses for these bacteria
cyano- first form of photosyntheies realses oxygen back into the atmosphere
human impacts on nirtogen cycle
- burning of fossil fuels
- fertilizers
-run off
-leacing - eutrophication
list some rapid and slow cycling parts of the carbon cycle
vegetation , forest fires, fossil fuels, decompistion
slow: rocks, ocean and atmosphere
