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IGCSEBiology
Trial Class

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

Ecosystems and Food Chains 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 organisms interact in ecosystems through feeding relationships.

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 2 Both 3 marks Difficulty 2/5

    Define the following terms: (a) producer, (b) consumer, (c) decomposer.

    Show model answer and marking guidance
    1. (a) Producer: an organism that makes its own food by photosynthesis: usually a green plant.
    2. (b) Consumer: an organism that obtains energy by eating other organisms.
    3. (c) Decomposer: an organism that breaks down dead organic matter: e.g. Bacteria, fungi.

  2. Question 2

    Paper 4 Both 4 marks Difficulty 3/5

    In the food chain: grass → grasshopper → frog → snake → eagle, name (a) the producer, (b) a primary consumer, (c) a secondary consumer, (d) the top predator.

    Show model answer and marking guidance
    1. (a) Producer: grass.
    2. (b) Primary consumer: grasshopper.
    3. (c) Secondary consumer: frog.
    4. (d) Top predator: eagle.

  3. Question 3

    Paper 4 Extended 3 marks Difficulty 4/5

    Using a food web, explain what would happen to the population of frogs if the grasshopper population decreased significantly.

    Show model answer and marking guidance
    1. Frogs would have less food: their population would decrease.
    2. Frog predators (e.g. Snakes) would also have less food: their population may decrease.
    3. Alternative prey for frogs (if any in the web) would experience increased predation.

  4. Question 4

    Paper 2 Core 2 marks Difficulty 1/5

    State what the arrows in a food chain represent.

    Show model answer and marking guidance
    1. The direction of energy flow / energy transfer.
    2. From the organism being eaten to the organism eating it.

  5. Question 5

    Paper 4 Both 3 marks Difficulty 3/5

    Explain why food chains rarely have more than four or five trophic levels.

    Show model answer and marking guidance
    1. Energy is lost at each trophic level (as heat from respiration, in excretion, and in uneaten parts).
    2. Only about 10% of energy passes from one level to the next.
    3. By the fourth or fifth level, there is not enough energy to support another trophic level.

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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