Human Influences on the Environment (Edexcel GCSE Biology: Combined Science)

Exam Questions

57 mins8 questions
1
Sme Calculator
4 marks
Waste products from human activities, such as agriculture or manufacturing, can contaminate the environment. Careful control of pollution levels in waterways is an important factor in maintaining the biodiversity of an ecosystem.

(i)
Define what is meant by biodiversity.
(1)

(ii)
Contamination from pollution could alter the abiotic environment for the organisms in the community.

Suggest what impact this may have on the biodiversity of the ecosystem.
(3)

Did this page help you?

2a
Sme Calculator
2 marks

Draw a ring around the most appropriate word from each of the square brackets to complete the sentence. 

A highly biodiverse ecosystem is [stable / large / successful] because of the

number of [competing / complementary / interdependent] species it contains.

2b
Sme Calculator
1 mark

Which of A - D is most likely to lead to a biodiverse ecosystem?

  A A large number of unconnected food chains
  B A large number of interconnected food chains
  C A small number of unconnected food chains
  D A small number of interconnected food chains

2c
Sme Calculator
2 marks

Figure 1 shows a food web from a marine ecosystem.

food-web---sea-2

Figure 1

Using one example from Figure 1, describe the effect on this ecosystem if the fish were removed by human activity (too much commercial fishing).

2d
Sme Calculator
2 marks

Identify the producer species in Figure 1.

2e
Sme Calculator
1 mark

Which of the factors A - D is not likely to have a negative impact on biodiversity of the marine ecosystem shown in Figure 1?

  A Human introduction of more lobsters into the area
  B Global warming
  C Sewage ingress into the sea
  D Imposition of fishing quotas

Did this page help you?

3a
Sme Calculator
3 marks

Figure 1 shows how the production of fish from fish farms has changed between 1950 and 2010.


fish-farming-sq

Figure 1

(i)

Describe the trend shown in Figure 1

(1)

(ii)

Suggest an explanation for the trend described in part (i)

(2)

3b
Sme Calculator
3 marks

Describe how fish farming methods ensure maximum yield.

3c
Sme Calculator
3 marks

Fish farms are sometimes responsible for eutrophication due to excess nutrients which leak into the surrounding ecosystems. 

Explain how these excess nutrients can lead to eutrophication in the surrounding ecosystems.

3d
Sme Calculator
2 marks

Sometimes fish from fish farms may escape into the nearby waterways with negative impacts on the native species in the surrounding ecosystems.

Identify two possible negative impacts of non-indigenous species.

Did this page help you?

4a
Sme Calculator
1 mark

State the term given for the introduction of new diseases by non-indigenous species to a native population.

4b
Sme Calculator
3 marks

Complete Table 1 below by identifying whether the given scenario describes a competition effect on native species caused by a non-indigenous species.

Table 1

Scenario

Competition effect Yes/No

The introduction of rabbits in a region leads to a decline in the population of native hares.  
Invasive plants consume more water, leaving less for native plants.  
A larger new species of bird is introduced that feeds on larger prey.  
4c
Sme Calculator
4 marks

List, in order, the stages of eutrophication, starting from the runoff of fertilisers and ending with the decrease in dissolved oxygen.

4d
Sme Calculator
2 marks

Give two consequences of the increasing demand for land to sustain the growing human population.

Did this page help you?

1
Sme Calculator
6 marks

Figure 1 shows a river and the location of a fertiliser factory. The arrows indicate the direction of the flow of the river.

zs9DJTQl_1

Figure 1

A scientist recorded the nitrate concentrations of the water at site A and site B. Her results are shown in the table.

nitrate-concentration-1a
Figure 2
(i)
Calculate the mean nitrate concentration found at site B.
(2)
(ii)
The scientist observed algae and some dead fish in the river at site B. These were not present at site A.

Give an explanation for these observations.
(4)

Did this page help you?

2
Sme Calculator
5 marks

Water pollution can be caused by an increase in nitrates and phosphates.

Explain the problems associated with an increase of nitrates and phosphates levels in a lake.

Did this page help you?

3
Sme Calculator
1 mark

The size of the dung beetle popultation in Tayrona National Park showed a significant negative impact of human activity to the biodiversity of the area.

Suggest a suitable conservation method to protect and maintain the species in this ecosystem.

Did this page help you?

4a
Sme Calculator
7 marks

Figure 1 shows a salmon fish farm in the sea.

QXi2B_Pp_7

Figure 1

(i)
Explain the benefit to the fish farmer of the wrasse being able to enter the net to where the salmon are being kept.
(3)
(ii)
In Scottish fish farming, huge quantities of wrasse have been caught from their natural environment and relocated to the salmon farms as a biological control.

Marine conservation experts have suggested that overuse of non-indigenous species in fish farming practises may have a negative impact on biodiversity.

Discuss the negative effects that wrasse relocation may have on biodiversity
(4)
4b
Sme Calculator
5 marks

Complete the Figure 2 to provide a solution to each of the problems associated with farming fish in fisheries.


Problem Solution
Death from disease  
Eutrophication due to pollution  
Predation  
Small fish with low mass  
Inter-specific competition  

Figure 2

Did this page help you?