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.
💡 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.
Practice questions for Biodiversity and Human Impacts
What is the best definition of biodiversity?
Explain why deforestation leads to a reduction in biodiversity.