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IGCSEBiology
Trial Class

Original practice · 5 questions · 15 marks · about 17 minutes

Pollution and Conservation Practice Questions

Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.

These questions test your understanding of how human activities cause pollution and what conservation measures can be taken.

Before you open the answers

  • Attempt every question without notes.
  • Show working for calculations and write complete biological statements.
  • Use the suggested time as a guide, not a strict limit on the first attempt.

These are original practice questions. They do not reproduce an official Cambridge paper or official mark scheme.

  1. Question 1

    Paper 4 Extended 4 marks Difficulty 4/5

    Describe the process of eutrophication in a lake and explain how it leads to the death of fish.

    Show model answer and marking guidance
    1. Excess fertilisers from farmland wash into the lake (run-off).
    2. Algae grow rapidly on the surface (algal bloom), blocking light to underwater plants.
    3. Plants die and decomposers (bacteria) multiply, breaking down the dead matter.
    4. Bacteria use up oxygen (aerobic respiration): oxygen levels drop and fish suffocate.

  2. Question 2

    Paper 4 Both 3 marks Difficulty 3/5

    State three effects of untreated sewage being released into a river.

    Show model answer and marking guidance
    1. Increases bacterial growth (decomposers): they use up dissolved oxygen.
    2. Reduced oxygen levels kill fish and other aquatic organisms.
    3. Spread of waterborne diseases (cholera, typhoid) from pathogens in sewage.

  3. Question 3

    Paper 4 Extended 3 marks Difficulty 3/5

    Explain two methods of conserving endangered species.

    Show model answer and marking guidance
    1. Captive breeding programmes: breeding endangered animals in zoos and releasing them back into the wild.
    2. Establishing nature reserves / protected areas: preventing habitat destruction.
    3. Seed banks: storing seeds of endangered plant species for future planting.

  4. Question 4

    Paper 2 Core 2 marks Difficulty 1/5

    Name two types of air pollution caused by human activities.

    Show model answer and marking guidance
    1. Carbon dioxide (from burning fossil fuels): contributes to climate change.
    2. Sulfur dioxide (from burning coal/oil): causes acid rain.

  5. Question 5

    Paper 4 Extended 3 marks Difficulty 4/5

    Explain why maintaining biodiversity is important for ecosystems and for humans.

    Show model answer and marking guidance
    1. Greater biodiversity makes ecosystems more stable / resilient to change.
    2. Many species provide resources for humans: medicines, food crops, materials.
    3. Loss of one species can disrupt food webs and affect many other organisms.

Mark the set consistently

Award a point only when the idea is clearly present in the written answer. Correct any missed point in a complete sentence, then test the same skill on a different question several days later.

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