Syllabus Edition

First teaching 2015

Last exams 2025

Communities & Ecosystems (DP IB Environmental Systems & Societies (ESS): SL): Exam Questions

45 mins10 questions
1
2 marks

Define the term community in the context of environmental systems and ecology.

2a
2 marks

State the word equation for aerobic respiration.

2b
1 mark

State the main energy transformation occurring during respiration.

3a
3 marks

Construct a systems diagram to represent photosynthesis.

3b
1 mark

State the main energy transformation occurring during photosynthesis.

4
2 marks

Define bioaccumulation.

1a
2 marks

The figures below show a pyramid of numbers and a pyramid of biomass for a tropical rainforest ecosystem.

pyramid-of-numbers
pyramid-of-biomass

i)

Explain how the pyramid of numbers shown above can have fewer producers than consumers.

[1]

ii)

State one other type of ecological pyramid that can be used to demonstrate trophic levels within ecosystems.

[1]

1b
2 marks

Evaluate pyramids of numbers as a method of representing trophic levels within ecosystems.

2a
2 marks

Use the figure below to produce a food chain that includes exactly four trophic levels.

screenshot-2023-07-25-at-16-18-42
2b
2 marks

Outline how two named human activities can alter the pyramid structure of the trophic levels within a tropical rainforest ecosystem.

3a
4 marks

Outline the role of primary producers in ecosystems.

3b
4 marks

Explain the vulnerability of top carnivores to non-biodegradable toxins.

4
2 marks

Define the term ecosystem.

1
7 marks

Evaluate the use of food webs as models for studying ecosystems.

2
9 marks

Discuss the impacts of persistent or non-biodegradable pollutants, such as DDT or mercury, on ecosystems.