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IGCSEBiology
Trial Class

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

Antibiotic Resistance 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 bacteria develop resistance to antibiotics and why this is a global health concern.

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

    Explain how a population of bacteria can become resistant to an antibiotic through natural selection.

    Show model answer and marking guidance
    1. Random mutation in some bacteria gives resistance to the antibiotic.
    2. When the antibiotic is used, non-resistant bacteria are killed.
    3. Resistant bacteria survive and reproduce: passing the resistance gene to offspring.
    4. Over time, the proportion of resistant bacteria in the population increases.

  2. Question 2

    Paper 4 Both 3 marks Difficulty 3/5

    State three steps that can help reduce the development of antibiotic resistance.

    Show model answer and marking guidance
    1. Only use antibiotics when prescribed by a doctor / not for viral infections.
    2. Always complete the full course of antibiotics: even if feeling better.
    3. Use antibiotics in the correct dose: not under-dosing.

  3. Question 3

    Paper 4 Extended 3 marks Difficulty 3/5

    Explain why antibiotics are effective against bacteria but not against viruses.

    Show model answer and marking guidance
    1. Antibiotics target specific features of bacterial cells (e.g. Cell wall synthesis, protein synthesis).
    2. Viruses do not have their own cell machinery / metabolic processes.
    3. Viruses replicate inside host cells: antibiotics cannot target them without damaging the host cell.

  4. Question 4

    Paper 2 Core 2 marks Difficulty 2/5

    Define the term "antibiotic".

    Show model answer and marking guidance
    1. A substance that kills or inhibits the growth of bacteria.
    2. Examples include penicillin and amoxicillin.

  5. Question 5

    Paper 4 Extended 3 marks Difficulty 5/5

    MRSA (methicillin-resistant Staphylococcus aureus) is a concern in hospitals. Explain why MRSA is difficult to treat and suggest how its spread can be reduced.

    Show model answer and marking guidance
    1. MRSA is resistant to many common antibiotics: few effective treatments remain.
    2. Spread can be reduced by strict hand hygiene and using alcohol gel between patients.
    3. Isolating infected patients prevents cross-contamination.

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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