OCR GCSE Biology B (Twenty First Century)
OCR GCSE Biology B B6.4 How is biodiversity threatened and how can we protect it? Exam Questions
Free OCR GCSE Biology B exam questions for B6.4 How is biodiversity threatened and how can we protect it?, with a mark scheme for every pack. Covers biodiversity, human population growth, habitat loss, deforestation, pollution, climate change, invasive species, overexploitation, conservation and sustainability.
B6.4 How is biodiversity threatened and how can we protect it? exam questions
2 question packs of real past exam questions, each with its mark scheme. Do not stop after a few: answer as many as you can without notes, then mark every answer with the mark scheme. The more questions you do, the more quickly you will spot how examiners ask about each idea.
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About OCR GCSE Biology B B6.4 How is biodiversity threatened and how can we protect it?
B6.4 closes the course content on Life on Earth by looking at biodiversity, why it matters and how human activity threatens it. You need to describe threats including habitat destruction, deforestation, pollution, climate change, invasive species and overexploitation, and explain the effects on ecosystems. Methods of protection include protected areas, breeding programmes, seed banks, reintroduction, reducing waste and sustainable practices. The topic draws on ecosystems in B3.3 and B3.4 and classification in B6.3. Examiners often ask you to interpret data on species decline and evaluate conservation strategies, considering economic and social factors.
What you need to know
- Biodiversity Biodiversity is the variety of all the different species of organisms on Earth or within an ecosystem. High biodiversity makes ecosystems more stable because species depend on each other.
- Human impact A growing human population uses more resources and land, producing more waste and pollution in air, water and land.
- Habitat loss and deforestation Clearing land for farming, building and quarrying destroys habitats. Deforestation also releases carbon dioxide and reduces carbon dioxide removal by photosynthesis.
- Climate change and pollution Rising temperatures change distribution and migration patterns of species. Pollutants such as fertiliser runoff can cause eutrophication and kill aquatic life.
- Invasive species and overexploitation Introduced species can outcompete native species or spread disease. Overfishing and hunting can reduce populations below the level needed to recover.
- Protecting biodiversity Measures include nature reserves and protected areas, breeding programmes for endangered species, seed banks, reintroducing hedgerows and field margins, reducing deforestation and carbon emissions, and recycling to reduce landfill.
Common mistakes in B6.4 How is biodiversity threatened and how can we protect it?
- Defining biodiversity as the number of organisms. It is the variety of different species.
- Saying deforestation increases carbon dioxide only by burning. Fewer trees also means less carbon dioxide absorbed by photosynthesis, and decomposition releases carbon dioxide.
- Giving vague answers like protect animals. Name the specific method and explain how it helps.
- Ignoring conflicting needs in evaluations. Consider costs, local jobs and food supply as well as conservation benefits.
- Stating that extinction of one species has no wider effect. Food webs mean loss of one species affects others.
Try three B6.4 How is biodiversity threatened and how can we protect it? exam-style questions
1. Define the term biodiversity. (1 mark)
Show the mark scheme answer
The variety of all the different species of organisms on Earth or within an ecosystem.
2. A frog population fell from 1200 to 780 over ten years. Calculate the percentage decrease. (2 marks)
Show the mark scheme answer
1200 minus 780 = 420; 420 / 1200 x 100 = 35%.
3. Describe and explain two ways farmers can increase biodiversity on their land. (4 marks)
Show the mark scheme answer
Plant or keep hedgerows and field margins; these provide habitats and food for many species; reduce use of pesticides and fertilisers; this avoids killing non-target species and prevents eutrophication of nearby water.
B6.4 How is biodiversity threatened and how can we protect it? FAQs
What does OCR GCSE Biology B B6.4 cover?
It covers what biodiversity is, how human activities such as deforestation, pollution and overexploitation threaten it, and the ways it can be protected.
Which paper is B6.4 examined in?
J257 has two papers at each tier, Breadth in Biology and Depth in Biology, and content from any chapter, including B6, can be assessed on either one. Expect it to be linked to ideas about science and to other chapters.
How do I evaluate a conservation method?
Explain how the method helps biodiversity, then consider costs, effects on local people and the economy, and how effective it is likely to be, before giving a conclusion.
