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GCSE AQA Biology 9-1 > B18 Biodiversity and ecosystems > Flashcards

B18 Biodiversity and ecosystems Flashcards

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1
Q

what is biodiversity?

A

the variety of all the different species of organisms on Earth, or within an ecosystem

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2
Q

what does high biodiversity ensure?

A

stability in ecosystems by reducing dependence on one species for food, shelter and maintenance of the physical environment

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3
Q

how does an increasing human population affect land and the environment?

A
  • land used for building and farming which destroys habitats and reduces biodiversity
  • quarrying reduces land available for other organisms
  • wasted produced by humans pollutes the environment and processing takes up land
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4
Q

how is land being polluted?

A
  • sewage
  • household waste and industrial waste in landfill
  • toxic chemicals leaching into soil
  • pesticides used in farming
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5
Q

how is water being polluted?

A
  • sewage
  • fertilisers
  • toxic chemicals (pesticides, herbicides)
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6
Q

what is eutrophication?

A
  • pesticides run off into a body of water and cause increased growth of algae
  • this blocks light and stop other plants photosynthesising so they die
  • microbes decompose the dead plants and use up lots of oxygen in the water
  • there is now not enough water to support other organisms so they die and are decomposed
  • this causes more oxygen to be used up
  • the water body then becomes dead
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7
Q

how is acid rain formed?

A

sulfur dioxide gas and nitrogen dissolve in rainwater after being formed by burning fossil fuels with impurities

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8
Q

what are the effects of acid rain?

A
  • directly damages plants and roots
  • causes water bodies to become too acidic
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9
Q

what is smoke pollition?

A

solid particulates in the air

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10
Q

what is the effect of smoke pollution?

A
  • the particle reflect sunlight so less light hits the surface of the earth
    this causes a dimming effect
  • it can also damage human health directly
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11
Q

what is smog?

A

a haze of small particles and acidic gases

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12
Q

what are the reasons for deforestation?

A
  • to grow staple foods
  • to rear more cattle
  • to grow crops for biofuels
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13
Q

how does deforestation increase the amount of CO2?

A
  • burning the trees releases CO2 from combustion. the microbes that decompose the dead material also release CO2
  • it also reduces the rate that CO2 is removed from the atmosphere
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14
Q

how is peat made?

A

when plant material cannot decay completely because of acidic conditions or lack of oxygen

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15
Q

what is peat used for?

A

fuel
used in gardens as fertiliser

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16
Q

what does a loss of peat bogs mean?

A

loss of biodiversity
more CO2

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17
Q

what contributes to global warming?

A

increasing levels of methane and CO2

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18
Q

what are the effects of global warming?

A
  • loss of habitats
  • change in distribution
  • change in migration patterns
  • reduced biodiversity
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19
Q

what affects the distributionof species in an ecosystem?

A
  • availability of water
  • temperature
  • atmospheric gases
20
Q

how can biodiversity be maintained?

A
  • breeding programs
  • protection and regeneration of rare habitats
  • reintroduction of field margins and hedgerows
  • reduction of deforestation and CO2 emissions
  • recycling resources
21
Q

what are trophic levels?

A

the position of organisms within a food chain

22
Q

what is in trophic level 1?

A

producers

23
Q

what is in trophic level 2?

A

primary consumers (herbivores)

24
Q

what is in trophic level 3?

A

secondary consumers (carnivores who eat herbivores)

25
Q

what is in trophic level 4?

A

tertiary consumers (carnivores who eat secondary consumers)

26
Q

what are apex predators?

A

carnivores with no predators

27
Q

what do decomposers do?

A

break dowm dead material by secreting enzymes into the environment

28
Q

how is biomass measured?

A

the dried mass of biological material in grams
OR
wet biomass in grams

29
Q

what is the problem with using dry biomass?

A

you have to kill the living organism

30
Q

why is there less biomass at each trophic level?

A
  • not all parts of the organism are eaten
  • some biomass is passed out and lost as waste material
  • biomass is used in respiration
31
Q

how much energy from the sun is used by producers for photosynthesis?

A

1%

32
Q

how much biomass from each trophic level is transferred to the level above it?

A

approx. 10%

33
Q

how is biomass lost in an organism?

A

not all ingested material is absorbed

34
Q

how is biomass lost in organisms?

A
  • lost in faeces
  • lost in waste products of respiration and urine
  • glucose is used in respiration
35
Q

what is food security?

A

having enough food to feed a population

36
Q

what factors affect food security?

A
  • increasing birth rates
  • changing diets meaning food has to be transported
  • new pests and pathogens
  • environmental changes
  • const of agricultural inputs
  • conflicts
37
Q

what are factors to consider when looking at sustainable food security?

A
  • maintaining soil quality
  • efficient ways to produce food
  • take care of fish stocks
38
Q

what does decreasing the number of stages in a chain do?

A

increase the efficiency of food production

39
Q

how can the efficiency of food production be artificially managed?

A
  • limiting movement of animals
  • controling temperature of surroundings
  • high protein diets
40
Q

what is the advantage of fish farming?

A

it protects wild stocks of fish and produces cheap protein

41
Q

what is the disadvantage of farming fish?

A

ethical concerns about the artificial conditions

42
Q

how can overfishing be reduced?

A
  • controlling net sizes
  • introduce quotas
43
Q

how is mycoprotein produced?

A
  • fusarium is grown on glucose syrup in aerobic conditions
  • the biomass is harvested and purified
  • it is then dried and shaped
44
Q

what are GM crops used for?

A

they are developed for increased yields or better nutrition

45
Q

how is insulin produced?

A

genetically modified bacteria

GCSE AQA Biology 9-1 (20 decks)

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