Human Impact: Biodiversity, Pollution & Conservation (Cambridge (CIE) IGCSE Biology)

Exam Questions

2 hours28 questions
1
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5 marks

Table 1 contains a list of chemicals that are useful to humans.

Complete Table 1 by stating one way in which each chemical is useful.

Table 1

chemical

use of the chemical

antibiotic

 

fertiliser

 

herbicide

 

insecticide

 

pectinase

 

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2a
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4 marks

Fig. 1 is part of a newspaper article about pollution.

screenshot-2022-10-13-15-46-52

Fig. 1

State four sources of water pollution other than raw sewage. 

2b
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1 mark

Fig. 1 states that raw sewage must be treated to produce water free from pathogens.

Define the term pathogen.

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3a
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2 marks

Human activities have had a very negative impact on biodiversity in recent times.

Define the term biodiversity.

3b
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2 marks

Deforestation refers to the clearing of trees from a habitat.

Describe the effects of deforestation on biodiversity.

3c
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1 mark

State the ecological importance of maintaining biodiversity in an area.

3d
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4 marks

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One way of decreasing the negative effects of deforestation is to manage forests sustainably.

Give four examples of how forests can be managed sustainably.

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1
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6 marks

The chimpanzee lives in forests in central and western Africa. The chimpanzee is classified as an endangered species because its population has decreased greatly. 

(i)

Suggest why the chimpanzee population has decreased.

[2]

(ii)

Describe how a captive breeding programme can help to conserve chimpanzees in the wild.

[2]

(iii)

State two methods, other than captive breeding, of conserving endangered species.

[2]

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2
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5 marks

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There are many threats to species such as the marine iguana.

Describe ways endangered plant and animal species can be conserved.

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3a
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1 mark

The energy we use comes from a variety of sources. 

Fig. 1 shows the percentage of each source of energy used in one country in 2011. 

picture18

Fig. 1

Coal, natural gas and oil are types of fossil fuel.

Calculate the total percentage of energy in Fig. 1 that came from fossil fuels.

3b
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1 mark

Explain why fossil fuels are not sustainable resources.

3c
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3 marks

Combustion of fossil fuels releases carbon dioxide into the atmosphere. 

(i)

State the name of two other processes that release carbon dioxide into the atmosphere.

[2]

(ii)

State the name of one process that removes carbon dioxide from the atmosphere.

[1]

3d
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2 marks

Describe the effects on the environment of increasing carbon dioxide concentration in the atmosphere. 

3e
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3 marks

Improvements in food production have allowed human populations to increase.

Describe how modern technology has increased the production of crop plants. 

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4a
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4 marks

Fig. 1 shows part of the carbon cycle. Some of the arrows are missing.

cie-igcse-2018-s2-may-p3-q5a-carbon-cycle

Fig. 1

(i)

State all the letters in Fig. 1 that represent respiration.

[2]

(ii)

State the name of the process that the letter J represents.

[1]

(iii)

Draw an arrow on Fig. 1 to represent the process of feeding.

[1]

4b
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1 mark

Carbon dioxide is a greenhouse gas.

State the name of one other greenhouse gas.

4c
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4 marks

Deforestation can cause an increase in the concentration of carbon dioxide in the atmosphere.

(i)

State two other undesirable effects of deforestation.

[2]

(ii)

State two uses for land that has been cleared of trees.

[2]

4d
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5 marks

The forests in Brazil contain many endangered species.

Table 1 shows the area of forest that was removed in Brazil each year between 2006–2010.

Table 1

year

area of forest removed / km2

2006

14 286

2007

12 651

2008

11 911

2009

7 464

2010

7 000

(i)

Calculate the average area of forest removed per year from 2006 to 2010.

Give your answer in km2. Show your working.

[2]

(ii)

Describe the trend in the data shown in Table 1.

[1]

(iii)

Suggest two reasons for the trend you have described in part (ii).

[2]

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5a
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4 marks

Some animals are farmed intensively.

Describe the negative impacts to an ecosystem of intensive livestock production.

5b
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3 marks

State why fertilisers, herbicides and insecticides are used in farming.

5c
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2 marks

Fertilisers, herbicides and insecticides can all pollute water.

List two other sources of water pollution.

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6a
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5 marks

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There are many threats to wildlife in the Galapagos.

Describe ways in which endangered species can be conserved.

6b
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3 marks

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One aim of conservation is to maintain resources in natural ecosystems.

State three resources that natural ecosystems provide for humans.

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7a
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4 marks

Fig. 1 shows a photograph of an area where the trees have been cut down.

screenshot-2022-10-05-16-51-50

Fig. 1

(i)

State the name of the type of habitat destruction shown in Fig. 1.

[1]

(ii)

List three undesirable effects of habitat destruction.

[3]

7b
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3 marks

State three human activities, other than cutting down large areas of trees, that can cause habitat destruction.

7c
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3 marks

Describe how endangered species can be conserved.

7d
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3 marks

Human activity can cause pollution of the environment.

Table 1 shows some pollutants, the environment they pollute and some of the effects.

Complete Table 1.

Table 1

pollutant

environment

effect of pollutant on the environment

methane

air

 

herbicides

 

kills non-targeted plants

 

water

increased growth of water plants

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1a
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1 mark

The graph in Fig. 1 shows the area of forest land lost in Ecuador in the years 2014 - 2019 inclusive. 

ecuador-deforestation-1

Fig. 1

Calculate the total area of land lost to deforestation in Ecuador from the beginning of 2014 to the end of 2019. 

1b
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2 marks

Identify in Table 1 below the possible reasons for the change in the area of forest lost per year between 2014 and 2017.

Place a tick (✔) in the boxes below that apply.

Table 1

The local people stop growing maize

 

Less new house-building is needed for the population

 

The local people decided to farm sheep and goats

 

More trees have been planted

 

A company starts growing sugar cane for the production of biofuel

 

1c
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2 marks

Suggest two explanations for the reductions in loss of forest land in Ecuador in the years 2018 and 2019.

1d
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2 marks

Conservationists looking at the data in Fig. 1 would not be fully satisfied with the 2018 - 2019 trend shown in the data.

Explain why. 

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2a
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3 marks

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

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Fig. 1

A scientist recorded the nitrate concentrations of the water at site A and site B

Table 1 shows the results of this investigation.

Table 1

site

nitrate concentration / mg dm-3

sample 1

sample 2

sample 3

mean

A

16

23

21

20

B

52

71

66

63

Calculate the percentage difference in the mean nitrate concentration between site A and B.

Show your working and state the nature of the difference.

2b
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4 marks

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Scientists observed algae and dead fish at site B.

Suggest an explanation for these observations.

2c
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3 marks

Explain the importance of using chemical fertiliser in modern farming practices.

2d
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3 marks

Further tests revealed that the water at site B contained abnormally high levels of cadmium, which is a heavy metal. After analysing the remains of aquatic organisms from the site, the top carnivores were found to have a very high concentration of cadmium stored in their fat cells.

Suggest the risk of high levels of cadmium to the river ecosystem.

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3a
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2 marks

The oil palm is a tree that grows in tropical areas, whose oil has many uses in cooking, food preparation and as a detergent. It is also used in the manufacture of biofuels.

Fig. 1 shows the annual production of palm oil in Colombia (South America) since 2010. 

palm-oil-production---colombia-2

Fig. 1

Calculate the mean increase in palm oil production per year for the three year period 2014 to 2017.

Show your working and give your answer in thousands of metric tonnes per year.

3b
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5 marks

Biofuels produced from palm oil can be used as a more renewable alternative to fossil fuels. However, the replacement of forests with oil palm plantations to produce biofuels will change the composition of the atmosphere.

Explain how.

3c
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1 mark

When palm oil plantations are created, native forest is cut down and the biodiversity in the forest reduces dramatically. Even when demand for palm oil is low, there is still a benefit to the palm oil manufacturers in cutting down the native forest.

Suggest what that benefit is. 

3d
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3 marks

Growing trees for palm oil is an example of monoculture farming.

Explain three disadvantages of monoculture farming.

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