Edexcel GCSE Biology

Decomposition

Edexcel GCSE Biology revision on Decomposition. Aligned to the Pearson Edexcel GCSE Biology 1BI0 specification. This bank has 5 practice questions on this topic.

Sample questions (3 of 5)

  1. Question 1

    Which biological process do microorganisms use to release mineral ions from dead organic matter?

    • A) Extracellular digestion
    • B) Intracellular respiration
    • C) Active transport uptake
    • D) Photosynthetic fixation
    Show answer

    Answer: Extracellular digestion

    Decomposers like bacteria and fungi release enzymes into the environment. These enzymes break down complex organic matter into smaller, soluble molecules that the microorganisms can then absorb.

  2. Question 2

    What is the primary role of detritivores in the process of decomposition?

    • A) Increasing surface area
    • B) Producing heat energy
    • C) Fixing atmospheric gas
    • D) Neutralising soil acidity
    Show answer

    Answer: Increasing surface area

    Hint: Detritivores physically break down dead organic matter into smaller pieces.

  3. Question 3

    Why does a compost heap generate heat during the decomposition process?

    • A) Exothermic respiration
    • B) Endothermic reactions
    • C) Friction between debris
    • D) Absorption of sunlight
    Show answer

    Answer: Exothermic respiration

    Decomposers respire aerobically to gain energy from the organic matter they consume. This process is exothermic, meaning it releases thermal energy as a byproduct, raising the temperature of the compost heap.

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