This exam tips covers Exam Tips for Decomposition within Decomposition for GCSE Biology. Topic 4: Decomposition It is section 10 of 11 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 10 of 11
Practice
15 questions
Recall
20 flashcards
💡 Exam Tips for Decomposition
🎯 Common Question Types:
- Explain how [factor] affects the rate of decomposition (2–3 marks)
- Describe/evaluate the Required Practical on decay (3–4 marks)
- Compare decomposition rates in different environments (2–3 marks)
- Explain why biogas generators must be kept anaerobic (2 marks)
📝 Key Command Words:
- Explain: Give a reason — always link factor to enzyme activity to decomposition rate
- Describe: State what happens — no reason needed, but include all key steps
- Evaluate: Judge a suggestion — state whether it is correct or incorrect and why
- Suggest: Apply knowledge to a new context — use TOMP factors
⚠️ Common Mistakes to Avoid:
- Saying bacteria "eat" or "swallow" dead material — they secrete enzymes externally
- Forgetting fungi are also major decomposers, not just bacteria
- Saying "higher temperature = faster decomposition" without mentioning denaturation above the optimum
- Confusing decomposers (bacteria/fungi) with detritivores (earthworms/woodlice)
- Forgetting that biogas requires anaerobic conditions — oxygen destroys methane production