This exam tips covers Exam Tips within Biodiversity and Human Impacts for GCSE Biology. Topic 5: Biodiversity and Human Impacts on Ecosystems It is section 15 of 16 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 15 of 16
Practice
20 questions
Recall
19 flashcards
💡 Exam Tips
🎯 Common Question Types:
- "State the meaning of biodiversity" (1 mark) — mention variety of species
- "Explain how [human activity] reduces biodiversity" (2-4 marks) — always name the specific habitat destroyed and the species affected
- "Suggest how biodiversity could be maintained" (3-4 marks) — give named methods with brief explanations
- "Explain why peat bog destruction contributes to global warming" (3 marks) — requires full chain: carbon store → aerobic decomposition → CO₂ release → greenhouse effect
- 6-mark extended response — evaluate conservation versus human needs
📝 Key Command Words:
- State / Name — just identify it, no explanation needed
- Describe — give details of what happens (no why needed)
- Explain — give the reason WHY something happens (use "because" or "this means that")
- Evaluate — give both advantages and disadvantages, then make a judgement
- Suggest — apply your knowledge to a novel situation; there may be more than one valid answer
⚠️ Common Mistakes to Avoid:
- Saying deforestation "reduces oxygen" without explaining the CO₂ link — focus on CO₂ and greenhouse effect
- Forgetting that destroying peat bogs BOTH destroys habitat AND releases CO₂ — marks are given for both effects
- Confusing water pollution types — fertiliser run-off causes eutrophication, not direct toxicity
- Writing vague answers like "harms animals" — always name the specific mechanism (habitat loss, loss of food source, pollution of water supply)
- Forgetting positive human impacts exist — conservation is just as important as the negative impacts in exam questions
Quick Check: A conservation organisation wants to protect an endangered bird species. Give two different methods they could use and explain how each method helps maintain biodiversity.
Method 1: Captive breeding programme — breed the birds in a protected environment (e.g. zoo) to increase population numbers; individuals can later be reintroduced into suitable wild habitat, increasing the wild population and preventing extinction. Method 2: Protect and manage the habitat — designate key nesting and feeding areas as SSSIs or nature reserves; restrict harmful activities (building, farming, predator introduction) in these zones so the birds have safe breeding areas with sufficient food.