Oxford Revise AQA GCSE Combined Science Foundation | Chapter B18 answers

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B18: Humans and biodiversity

Question

Answers

Extra information

Mark

AO / Specification reference

01.1

deforestation

1

AO1

4.7.3.4

01.2

agriculture / to grow crops / land for cattle / rearing animals

1

AO3

4.7.3.4

01.3

Less photosynthesis / Combustion / burning (to clear land) /

Increased level of decay (of felled trees)

1

AO2

4.7.3.4

01.4

Removes shelter / habitat / food source for animal species

so fewer species can survive there / biodiversity reduced

1

1

AO2

4.7.3.1

4.7.3.4

01.5

Peat used to increase food production/as a cheap fuel

But reduces habitat area available/use as fuel releases CO2 into atmosphere

This reduces biodiversity/CO2 emissions a cause of climate change

Conclusion given on relative importance

1

1

1

1

AO3

02.1

Causes breathing difficulties / asthma / lung problems

Accept any other appropriate suggestions

1

AO1

4.7.3.2

02.2

Car exhausts

1

AO1

4.7.3.2

02.3

109 (µg/m3)

1

AO2

4.7.3.2

Ms 2b, 2f

02.4

Nitrogen oxide concentrations are highest during the working week / lowest at the weekends / lowest on a Sunday

1

AO3

4.7.3.2

02.5

More people travel (into the city) for work

Accept other reasonable suggestion

1

AO3

4.7.3.2

02.6

Ban cars from the city / promote sustainable transport / promote public transport / introduce charging to enter city centre

as this will reduce the number of vehicles entering the city

Accept other reasonable suggestion

1

1

AO3

4.7.3.2

03.1

Variety of all the different species of organism within an ecosystem / area / on the Earth

1

AO1

4.7.3.1

03.2

Breeding programmes

Reintroduction of hedgerows

1

1

AO2

4.7.3.1

03.3

If the one species of trees is destroyed/ killed by a pathogen

there is no other food source / shelter to support other organisms in the ecosystem/woodland

so their numbers will decrease

Accept reverse argument

1

1

1

AO2

4.7.3.1

04.1

Any one from:

  • glass
  • tin
  • aluminium
  • paper
  • cardboard
  • (some) plastics

1

AO1

4.7.3.6

04.2

Percentage of materials recycled increases over time

1

AO3

4.7.3.6

04.3

Any two from:

  • Less material is placed in landfill
  • Less raw materials need to be mined / used
  • Less energy is used to recycle materials (compared to manufacturing from raw materials)
  • Less CO2 emissions

Accept other reasonable benefits

2

AO1

4.7.3.6

04.4

Answer in the range 45–46%

1

AO3

4.7.3.3

05.1

thousands

plant

acidic

without

1

1

1

1

AO1

4.7.3.3

05.2

improve soil nutrient content

as a fuel

1

1

AO1

4.7.3.3

05.3

removal of peat destroys habitats – decreases biodiversity

burning peat releases carbon dioxide – contributes to global warming

1

1

AO1

4.7.3.3

4.7.3.5

06.1

biodiversity

greater

shelter

1

1

1

AO1

4.7.3.1

06.2

removing hedgerows – removes plants and reduces habitats

using pesticides – kills useful insects such as bees

using herbicides – kills unwanted plants that provide food for animals

1 mark for one correct

2 marks for all correct

2

AO2

4.7.3.1

06.3

reintroduce / plant hedgerows / field margins / use organic forms of pest control

Accept any other appropriate suggestion

1

AO2

4.7.3.1

4.7.3.6

07.1

carbon dioxide

methane

1

1

AO1

4.7.3.5

07.2

deforestation / more combustion of fossil fuels / increasing cattle / rice production

Accept any other appropriate suggestion

1

AO1

4.7.3.5

07.3

rising sea level – low lying areas flood resulting in loss of habitat

hotter or colder seasons – change in migration patterns

less rainfall in areas – loss of plant species

melting ice sheets – loss of habitats for polar bears

1 mark for one correct

2 marks for two correct

3 marks for all correct

3

AO2

4.7.3.5

08.1

More waste produced / more fuels burnt / more cars / greater energy consumption requiring more fossil fuels / increased extraction of raw materials

Accept any other appropriate suggestion

1

AO1

4.7.3.2

08.2

land pollution

water pollution

water pollution

air pollution

1

1

1

1

AO1

4.7.3.2

08.3

sulfur dioxide

dissolves

acidic

acid

1

1

1

1

AO1

4.7.3.2

09.1

Any two from:

  • Improved farming / fishing ability / methods of food production
  • ability to cure/ prevent diseases / better health care
  • no natural predators
  • ability to control environment by heating /light / better living accommodation

Accept any other appropriate reasons

2

AO1

4.7.3.3

09.2

Any two from:

  • building
  • roads
  • industry
  • agriculture
  • landfill
  • quarries / mining

2

AO1

4.7.3.3

09.3

Any two from:

  • Sewage
  • Fertiliser
  • toxic chemicals (such as pesticides / herbicides)

2

AO1

4.7.3.2

09.4

Any two from:

  • Carbon dioxide – contributes to greenhouse effect
  • Sulfur dioxide / nitrogen oxides – react with water vapour to form acid rain
  • Particulates – cause respiratory problems in humans

1 mark for gas

1 mark for description of effect

4

AO1

4.7.3.2

10.1

flowers – to attract insects to pollinate them

sharp spines – so herbivores do not eat the plant

small leaves – reduce water loss

1

1

1

AO2

4.7.1.4

10.2

Branching shallow roots

to gather any rainfall from a wide area

OR

Long / deep tap root

to reach underground water / the water table

1

1

AO3

4.7.1.4

10.3

Any two from:

  • Light
  • Space
  • mineral ions

2

AO1

4.7.1.1

10.4

Presence of new / increasing number of herbivores

So more plants get eaten

OR

New pathogen

which destroys plants by causing disease

1

1

AO2

4.7.1.3
⌃
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