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Edexcel IGCSE Biology 4 Ecology and the Environment Questions

Practise ecology and environment questions on sampling populations, biodiversity, food chains, biomass pyramids, energy transfer and carbon cycling.

Syllabus
First assessment 2019
Course
Biology 4BI1

Covered syllabus points

(a) The organism in the environment(b) Feeding relationships(c) Cycles within ecosystems(d) Human influences on the environment

Question 1

[Maximum number: 10]

The diagram shows part of a woodland food web.

Figure for Question 1 — Edexcel IGCSE Biology

Question (a)

(a)

Which organism is a primary consumer in this food web?

A

aphid

B

blackbird

C

fox

D

oak tree

[ 1 ]

Question (b)

(b)

Which of these describes the woodland community?

A

all the abiotic and biotic factors in the area

B

all the blackbirds in the area

C

all the different species and the habitat

D

all the different species in the area

[ 1 ]

Question (c)

(c)

This is one food chain from the food web.

 oak tree ⟶ mouse ⟶ fox \text { oak tree } \longrightarrow \text { mouse } \longrightarrow \text { fox }
[ 8 ]

Question (i)

(i)

A student counted 20 mice living around 4 oak trees. There were also 2 foxes in the area.

Draw a labelled pyramid of numbers for this food chain on the grid.
Your pyramid should be drawn to scale.

Figure for Question (i) — Edexcel IGCSE Biology
[ 3 ]

Question (ii)

(ii)

Photosynthesis results in 25000 kJ of energy being transferred to the biomass of the oak trees each year.

Only 8\% of this energy is transferred to the biomass of the 20 mice each year.

Calculate the mean amount of energy transferred to the biomass of one mouse each year.
mean amount of energy = kJ

[ 2 ]

Question (iii)

(iii)

Explain why only 8% of the energy stored in the biomass of the oak trees is used by the mice for growth.

[ 3 ]

Question 2

[Maximum number: 4]

The diagram shows a cycle found in ecosystems.

Figure for Question 2 — Edexcel IGCSE Biology

Question (a)

(a)

Give the name of the cycle.

[ 1 ]

Question (b)

(b)

Which process is represented by the letter W ?

A

combustion

B

decomposition

C

feeding

D

respiration

[ 1 ]

Question (c)

(c)

Which process is represented by the letter X ?

A

combustion

B

decomposition

C

feeding

D

respiration

[ 1 ]

Question (d)

(d)

Name a group of organisms that is responsible for decomposition.

[ 1 ]

Question 3

[Maximum number: 8]

Question (a)

(a)

Using the recommended amount of fertiliser on a crop increases crop yield. Some farmers think that adding extra fertiliser will give an even greater crop yield.

[ 5 ]

Question (i)

(i)

Some farmers apply more nitrogen fertiliser and more water to their fields than are needed.

Explain the biological consequences of applying more nitrogen fertiliser and more water than needed.

[ 5 ]

Question (b)

(b)

The atmosphere can be polluted by gases such as carbon monoxide released from industry.

Describe the effects of carbon monoxide on the human body.

[ 2 ]

Question (c)

(c)

Which of these is not a greenhouse gas?

A

carbon dioxide

B

methane

C

nitrogen

D

nitrous oxide

[ 1 ]

Question 4

[Maximum number: 14]

Limpets are marine animals that attach to rocks on coastal shores.

The diagram shows a food web that contains limpets.

Figure for Question 4 — Edexcel IGCSE Biology

Question (a)

(a)

Which are the trophic levels of the starfish in this food web?

A

primary consumer and secondary consumer

B

primary consumer and tertiary consumer

C

secondary consumer and tertiary consumer

D

secondary consumer only

[ 1 ]

Question (b)

(b)

State what is meant by the term population.

[ 1 ]

Question (c)

(c)

Explain why only 1% of the energy in the algae is transferred to the starfish.

[ 3 ]

Question (d)

(d)

Some scientists think that food webs on rocky shores are at risk from an increase in greenhouse gases.

The scientists record these two factors during August every year for 17 years.
- the number of limpets per m2m^{2} on a rocky shore
- the mean temperature at the same rocky shore

The graph shows the scientists' results.

Figure for Question (d) — Edexcel IGCSE Biology
[ 9 ]

Question (i)

(i)

Describe how the scientists could determine the number of limpets on the rocky shore.

[ 3 ]

Question (ii)

(ii)

Give one factor the scientists should control when comparing the number of limpets per m2m^{2} each year.

[ 1 ]

Question (iii)

(iii)

The scientists conclude that the combustion of fossil fuels is a risk to the food web.

Discuss the scientists' conclusion.
Use the information in the graph and your own knowledge to support your answer.

[ 5 ]
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