Describe the importance of biodiversity and explain how human activities can threaten it. In your answer, refer to the impact on ecosystems.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Scientists estimate that human activity has caused species extinction rates to rise to more than 1000 times the natural background rate. Many conservation organisations argue that protecting biodiversity should be a global priority.
Model answer (5 marks)
Biodiversity is the variety of living organisms in a given area or on Earth.
Greater biodiversity makes ecosystems more stable and resilient to change.
Human activities such as deforestation, habitat destruction, pollution and climate change reduce biodiversity.
The loss of one species can affect others in the ecosystem, for example by disrupting food chains or webs.
Reduced biodiversity can make an ecosystem less able to recover from change and more vulnerable to collapse.
Greater biodiversity makes ecosystems more stable and resilient to change.
Human activities such as deforestation, habitat destruction, pollution and climate change reduce biodiversity.
The loss of one species can affect others in the ecosystem, for example by disrupting food chains or webs.
Reduced biodiversity can make an ecosystem less able to recover from change and more vulnerable to collapse.
Examiner tips
- Use the exact terms from the mark scheme – e.g. ‘biodiversity’, ‘stable’, ‘resilient’, ‘deforestation’, ‘habitat destruction’, ‘pollution’, ‘climate change’, ‘food chains/webs’, ‘collapse’.
- Structure the answer in five clear points matching the five marks.
- Show cause–effect links: human activity → loss of species → ecosystem disruption → reduced stability.
- Keep sentences short and to the point – no extra words.
Mark scheme (5 marks)
- Biodiversity refers to the variety of living organisms / species in an area (or on Earth)
- Greater biodiversity makes ecosystems more stable / resilient to change
- Human activity such as deforestation / habitat destruction / pollution / climate change reduces biodiversity
- Loss of one species can affect others in the ecosystem, e.g. disrupting food chains / webs
- Reduced biodiversity can reduce the stability of an ecosystem making it less able to recover from change / more vulnerable to collapse
Key terms in this question
Related
- All Pearson Edexcel A-Level Biology A (9BI0) revision notes →
- How to answer a "Describe" question →
- Decode the mark scheme abbreviations →
More Biodiversity questions
- Biodiversity is important for the stability of ecosystems. Explain why a reducti…
- A conservation organisation is working to protect a rainforest region that conta…
- A wildlife charity is monitoring two woodland habitats: Habitat A, which has bee…
- A farmer converts a species-rich wildflower meadow into a field of a single crop…