Question 1
Which statement describes biodiversity?
- The number of organisms in an area
- The number of different species in an area
- The number of plants in an area
- The number of habitats in the world
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Answer: B (1)
Question 2
State three reasons why habitats are destroyed by human activity.
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- building houses / more land for housing (1)
- land for crop plants or livestock (1)
- extraction of natural resources / mining / quarrying (1)
- freshwater or marine pollution (1)
- Max 3
Question 3
People fishing remove most of the large predatory fish from a lake. Suggest how this could have a negative effect on the lake ecosystem.
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- the prey / smaller fish increase in number (1)
- they eat more of the producers / food source (1)
- so food web is altered / other species lose food and numbers fall (1)
Question 4
Which is an effect of deforestation?
- Less soil is lost
- Less carbon dioxide in the atmosphere
- More flooding
- More biodiversity
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Answer: C (1)
Question 5
Large areas of rainforest are cleared to graze cattle. Explain the undesirable effects of this deforestation.
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- biodiversity reduced as species lose habitat / food (1)
- some species may become extinct (1)
- soil lost / eroded because no roots to hold it (1)
- flooding because less water absorbed by roots / more run-off (1)
- carbon dioxide increases because fewer trees to photosynthesise / trees burnt or decay (1)
Question 6
Explain how pollution of a river can lead to destruction of the habitat of fish.
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- pollutants (e.g. sewage / fertiliser / plastic) make the water unsuitable / poisonous / reduce oxygen (1)
- so fish die or move away / cannot live there (1)