Explain why cells need to carry out respiration and describe what happens during aerobic respiration.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (5 marks)
1. Respiration releases energy from glucose.
2. The energy is used for cellular processes such as muscle contraction, active transport, protein synthesis and maintaining body temperature.
3. Aerobic respiration requires oxygen.
4. During aerobic respiration glucose is broken down (oxidised).
5. The products of aerobic respiration are carbon dioxide and water.
2. The energy is used for cellular processes such as muscle contraction, active transport, protein synthesis and maintaining body temperature.
3. Aerobic respiration requires oxygen.
4. During aerobic respiration glucose is broken down (oxidised).
5. The products of aerobic respiration are carbon dioxide and water.
Examiner tips
- Use the exact terminology: ‘energy is released from glucose’ and ‘oxygen is required’. Show the five points in order, matching the mark scheme. Include the main cellular processes that use the energy.
- common_mistakes
- :
- Writing ‘respiration’ instead of ‘aerobic respiration’ in point 3. Omitting the products (CO₂ and H₂O) or confusing them with by‑products of anaerobic respiration.
Mark scheme (5 marks)
- Respiration releases energy (from glucose)
- Energy is needed for (named) cellular processes, e.g. muscle contraction / active transport / protein synthesis / maintaining body temperature
- Aerobic respiration requires oxygen
- Glucose is broken down / oxidised during aerobic respiration
- Carbon dioxide and water are produced as products of aerobic respiration
Key terms in this question
Related
- All AQA A-Level Biology (7402) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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