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biology paper 2 > ecosystems and material cycles > Flashcards

ecosystems and material cycles Flashcards

(75 cards)

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1
Q

order of ecosytem

A

producer -> primary consumer -> secondary consumer -> tertiary consumer

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2
Q

producer

A

always a photostnthetic organism as these are the osurce of all biomass on earth
use light energy to synthesise glucpse

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3
Q

what do arrows show in food chain

A

transfer of biomass

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4
Q

primary consumer

A

often herbivores
and prey species

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5
Q

secondary consumer

A

predators as they catch and consume other organsims but also prey to som e

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6
Q

tertiary consumers

A

predators and often carnivores
top predator will be the apex as they have no predators

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7
Q

what do animals compete for

A

food
space
mates

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8
Q

what do plants compete for

A

space
mineral ions
water
light

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9
Q

oxygen as a factor affecting an ecosystem

A

abiotic
in water for aquatic animals

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10
Q

carbon dioxide as a factor affecting an ecosystem

A

abiotic
for plants for photosynthesis

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11
Q

light intensity as a factor affecting an ecosystem

A

abiotic
photosynthesis
sunburn

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12
Q

temperature as a factor affecting an ecosystem

A

abiotic
enzymes
transpiration rate

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13
Q

wind intensity as a factor affecting an ecosystem

A

abiotic
transpiration
flight
exposure

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14
Q

moisture levels as a factor affecting an ecosystem

A

abiotic
all organisms need water to survive

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15
Q

soil ph / mineral ions as a factor affecting an ecosystem

A

abiotic
enzymes
plants require minerals

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16
Q

new predators as a factor affecting an ecosystem

A

biotic
prey species are not prepared or able to adapt to avoid predatation

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17
Q

new pathogens as a factor affecting an ecosystem

A

biotic
organisms will have no resistance to the disease if they have not been infected before

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18
Q

amount of food as a factor affecting an ecosystem

A

biotic
limited food due to a reduction in population size can increase competition and reduce survivial

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19
Q

competition as a factor affecting an ecosystem

A

biotic
competition with other species for resources could lead to one outcompeting the other until there are nmot enough individuals left to breed

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20
Q

how does disease affect the population size using a food web example

A

if a new pathogen reduces number of secondary consumers in a community
primary consumers increase as fewer predators
other secondary consumers could decrease as tertiary consumer must eat more of them to make up for lack of diseased species

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21
Q

the rules of predator and prey population graphs

A

as prey increases, predators increase with a delay
too many predators eat toomany prey the predator size decreases as there was a decrease in prey
fewer predators mean prey increases
can never be more predators than prey

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22
Q

community

A

all the populations of different species in an area

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23
Q

habitat

A

non living bits ecosystem

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24
Q

ecosystem

A

interactions between living and non living parts

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25
examples of interdependence
shelter food pollination seed disposal
26
parasitism
parasites live in or on host parasite takes nutrients from host and gives nothing in return eg cats and fleas parasites take as much as possible w/o killing host
27
mutualism
both species benefit from the relationship eg bees and flowers bee gets nectar and flowers get pollinated eg algae and fungi algae photosynthesise and share sugars fungi shelters algae from harsh climate
28
random sampling
used to estimate number of species in a certain area and their abundance random number generator to slect coordinates place a large number of quadrats and count the amount
29
systematic sampling (transect)
used to see how a changing abiotic factor affects the number or distribution of a species lay a transect along a changing environment and place quadrats regularly repeat whole transect in a different position
30
what trophic level are producers
1
31
what trophic level are tertiary consumers
4
32
what do decomposers do
break down all the biomass from dead organisms into small soluble molecules by secreting enzymes they then absprb the small molecules by diffusion
33
rules for drawing pyramids of biomass
bars must touch bars should be cnetred]producers alwasy at bottom width of bar relative to biomass
34
general gist of biomass pyramids
lots of producers mass less less less as it goes up
35
around what percent of energy is passed on at each step in a food chain
10 percent
36
what percentage of the suns energy do producers convert in photosynthesis
1
37
why is energy or biomass lost at each level
glucose used for respiration not all ingested material is absorbed]some absorbed material is lost as waste eg urea and co2
38
the loss of biomass limits food chain sizes to around how many trophic levels and why
4-5 not enough biomass is passed on to support organsisms survival
39
efficiency of transfer calculation
biomass of higher level ----------------------------------- x100 biomass of lower level
40
why does deforestation ocur
massive population increase more people need more space and food more land is cleared for building and farming natural land destroyed
41
effects of deforestation
reduces amount of co2 removed from atmosphere through photosynthesis contributing to global warming burnin g/ decaying wood releases co2 increases soil erosion and lfooding deforestation is usually for room for cattle which produce methane a greenhouse gas
42
pollution reduces biodiversity because it
kills plants and animals
43
land pollution
landfill toxic chemicals in soil
44
water pollution
sewage and fertilisers create low oxygen conditions leading to eutrophication toxic chemicals
45
air pollution
smoke and gases from burning fossil fuels smoke harms lungs gases cause acid rain
46
eutrophication reducing biodiversity
fertiliser runoff or leaching - puts nitrogen and phosphorus into water - nutrients algae blooms and grows due to the new presence of nutrients the algae blocks light so plants at the bottom cannot photosyntheise and die bacteria use oxygen to break down dead algae fish sufficate due to lack of oxygen
47
fish farming reducing biodiversity
large tanks or nets catch fish waste chemicals pathogens and parasites can harm marin elife nearby wild fish populations used to feed caught fish escaped fish can compete with indigenous species and predators get trapped
48
introducing non indigenous species reducing biodiversity
many outcompete native populations may kill native species affects food chains and ecosystems and can lead to local extinctions
49
5 ways scientists are trying to maintain biodiversity
breeding programmes for endangered species protection and regeneration of rare habitats recycling reusing and reducing waste to avoid landfill reintroduction of hedges and wildlife corridors around farmland reducing deforestation and co2 emissions by governments signing agreements
50
food security
having enough food to feed a population
51
5 things reducing good security
environmental changes leading to draughts or floods causing famine increasing cost of agricultural inputs like fertiliser or energy conflict in countries reducing access to food or water new pests or pathogens damaging crops/livestock changing diets in developing countries means in demand food is transported around the world
52
what is the carbon cycle
all materials must be recycled to provide raw materials for new organisms to grow in an ecosystem carbon cycle returns carbon from carbs lipids and proteins in organisms to the atmosphere as co2 so plants can use it in photosynthesis
53
what do decomposers do in the carbon cycle
break down dead organisms and return nutrients to soil for plants to uptake through roots
54
everything in the carbon cycle adding co2 to atmosphere
decomposer respiration - release co2 during decay animal respiration root respiration dead organisms turn into fossil fuels ( but take millions of years to form) HUMANS: burn fossil fuels, burn wood
55
what is the only process which removes co2 from atmosphere
photosynthesis
56
water cycle steps
1 - transpiration and evaporation from plants and sea HEAT FROM SUN 2 - condensation 3- precipitation 4 percolation and run off back into sea
57
first way of turning sea water into fresh drinking water... THERMAL DESALINATION
seawater is distilled expensive -> requires energy contribytes to global warming as it uses fossil fuels
58
second way of sea to free to drink... REVERSER OSMOSIS
in reverse osmosis, pressure is used to force water in sea water through a semi permeable membrane from low conc to high conc
59
step 1 of the nitrogen cycle
nitrogen gas is converted to nitrate compounds by bacteria in root nodules of plants or in soil (nitrogen fixing bacteria) can also be foxed by lightning and the harber process
60
step 2 of the nitrogen cycle
nitrifying bacteria converts ammonia to nitrates in the soil these can be taken up by plant roots and used to make amino acids and proteins
61
step 3 of the nitrogen cycle
bodies of dead organisms contain proteins decomposers break this down to return nitrogen to the soil as ammonia nitrifying bacteria converts this back to nitrates for more plants to gobble
62
step 4 of the nitrogen cycle
in aerobic cpnditions eg waterlogged soil denitrifying bacteria can break down nitrates and return it to the atmosphere as nitrogen gas this decreases soil fertility
63
how does crop rotation increase the soil fertility
cycle the rotation of crops that will hsve root nodules and nitrogen fixing bacteria eg peas, beans and clover and they will put nitrogen into the soil also have normal food crops which will remove nitrogen to balance it all out i think
64
how do natural fertilisers increase soil fertility
natural: made from waste such as manures and comppost that will slowly decompose and slowly release nutrients
65
how do synthetic fertilisers increase soil fertility
chemical fertilisers can be used like ammonium nitrate made from the haber process these are expensive and cause pollution which can reudce biodiversity
66
what do indicator species do in water
presence of certain species in water can indicate the levels of pollution as water pollution will decrease oxygen so species that can tolerate high pollution are afapted for low oxygen environments
67
water pollution indicators from needing high o2 (low pollution) to needed little o2 (extreme pollution)
mayfly larva low dragonfly nymph low freshwater shrimp slight water louise medium sludgeworm high no life xtreme
68
air pollution indicators
some species such as fungus (rose black spot) and lichens can be particularly sensitive to sulphur dioxide conc in the air measuring thei number and distrubution can indicate the levels of pollution in the air
69
3 factors affecting decay
high temp = quicker high moisture = quicker high oxygen concentration = quicker
70
what do decomposers use to brek down large moilecules into smaller ones and examples pls
enzymes starch AMYLASE glucose protein PROTEASE amino acids lipids LIPASE glycerol and fatty acids
71
large anaerobic fermenters are used with what to produce what
with specialist microorganisms produce methane
72
milk decay
due to bacteria releasing enzymes that digest lactase sugars releasing lactic acid which gives the milk a sour taste
73
the 3 variables of the milk decay prac
independent - temperature dependent - change inph, time, colour change of ph indicator control - volume and conc of milk and lipase
74
results of milk decay prac
rate = change in ph / time or time to colour change / 1 should increase at higher temps until a point when the lipase becomes denatured or all lipids are digested
75
3 alt ways of measuring decay
loss mass / time temp increase / time as decay occurs temp will increase other enzyme reactions eg smylase digesting starch from fungi size of clear zone / time

biology paper 2 (4 decks)

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