AQA GCSE Biology (8461), Higher tier · Ecology › Biodiversity and human interaction
Practise Maintaining biodiversity. 14 exam-style questions plus unlimited generated ones on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
Scientists and concerned citizens have set up programmes to reduce the negative effects of humans on ecosystems and biodiversity.
(a) Which two of these programmes help to maintain biodiversity? Tick (✓) two boxes.[2]
Breeding programmes for endangered species
Increasing the use of landfill
Removing hedgerows to make larger fields
Protecting and regenerating rare habitats
(b) Give one other programme that reduces the negative effects of humans on biodiversity.[1]
(c) Farmers who grow only one type of crop are encouraged to plant hedgerows. Explain how this increases biodiversity.[2]
Show the answer and mark scheme
(a)Answer: Breeding programmes for endangered species; Protecting and regenerating rare habitats
(b)
reintroducing field margins and hedgerows
reducing deforestation
reducing carbon dioxide emissions
recycling resources rather than dumping waste in landfill
(c)
hedgerows provide habitats (food and shelter) for many species
so more different species can live on the farm
Question 2Medium6 marks
A farmer planted strips of wild flowers along the edges of some fields (field margins). Ecologists counted insects in fields with and without these margins. {table} shows the results.
[object Object]
(a) Calculate how many times more bumblebees were counted per hour in fields with margins than in fields without margins.[1]
(b) Explain why the wildflower margins increase the number of insect species.[2]
(c) Suggest how the wildflower margins could benefit the farmer's crops.[2]
(d) Suggest one reason why some farmers do not plant field margins.[1]
Show the answer and mark scheme
(a)Answer: 5.75
46 ÷ 8 = 5.75
(b)
the margins provide food (nectar / pollen) and shelter / habitats
for many different species of insect
(c)
more pollinating insects, so more crop flowers are pollinated / higher yield
more predators of pests (e.g. ladybirds) live in the margins, so fewer pests
less need for pesticides
(d)
less land for crops, so a lower yield / less income
the cost of seeds / time to manage the margins
the margins might contain weeds or pests
Question 3Hard8 marks
A town council plans to build 400 new houses on an area of lowland heath. Lowland heath is a rare habitat, and the site is home to several rare species of reptile, bird and insect. The council says the houses are needed because the population of the town is growing. A conservation group suggests building the houses on the site of an old factory nearby instead. This would cost more, because the land would first need to be cleaned of toxic chemicals.
(a) Evaluate the two options for building the new houses. Include the effects on biodiversity in your answer.[6]
(b) If the heath site is used, suggest two ways the builders could reduce the effect on biodiversity.[2]
Show the answer and mark scheme
(a)
heath site: destroys a rare habitat, reducing biodiversity
heath site: rare species could become locally extinct / lose food and shelter
heath site: building reduces the land available for other animals and plants
heath site: cheaper / quicker, and houses are needed for the growing population
factory site: reuses land that has already been developed, so no rare habitat is lost
factory site: cleaning up toxic chemicals reduces land pollution, which benefits wildlife and people
factory site: costs more / takes longer
compromise, e.g. build on part of the heath and protect or regenerate the rest
a justified conclusion about which option is better
Marked with levels of response: the full level descriptors are in the app.
(b)
leave part of the site as a protected habitat / nature reserve
move the rare species to other suitable heathland
plant native species / create green spaces, hedgerows or wildlife corridors
create or regenerate heathland elsewhere to replace what is lost