OCR A 6.3.2 · 14 written questions · 27 marks · about 30 minutes · marked as you go
This free quiz has 14 written exam questions on populations and sustainability, all taken from OCR A Level Biology A papers (A level, 2017 to 2025). Short answers mark themselves. For longer answers you write your answer, then tick off the OCR mark-scheme points you made, so you see exactly where the marks are. This quiz covers OCR A 6.3.2: how populations of predators, prey and competitors affect each other, the difference between conservation and preservation, sustainable timber and fishing, and how human activities on reserves are managed. OCR has set fewer short-answer questions on this topic than on most, so this quiz is shorter than the others in the series.
What the quiz covers (OCR A spec 6.3.2)
Interactions between populations (6.3.2(b)): explaining changes in a predator population from graph data, and discussing knock-on effects of a seabird decline through a food web.
Conservation and preservation (6.3.2(c)): in situ, ex situ and preservation approaches, why a reintroduction counts as conservation, when preservation is needed, and evaluating a peat bog management plan.
Sustainable resources (6.3.2(d)): producing timber sustainably by clear felling, government strategies for sustainable fishing and why international agreements matter.
Human activities and management (6.3.2(e)): ecotourism, conservation work made necessary by visitors, how predators reach islands, and explaining a decline in a top predator.
How to use it
Write every answer in full, as you would in the exam: the mark for each question is shown, so you know how much to write. When you self-mark, only tick a point if your answer clearly makes it, then read the examiner's tip under each question. Your progress is saved on your device, so you can do it in two sittings, and at the end you can retry just the questions where you dropped marks.
Prefer multiple choice? Try the 19-question Ecosystems and Populations multiple choice quiz first.
Open the Populations and Sustainability quiz in a new tab (easier on a phone)
Where students lose marks (from OCR examiners' reports and mark schemes)
Each point below is followed by wording that gained marks.
Reintroduction increases biodiversity: Many students said reintroducing beavers 'maintains biodiversity', but adding a species back to an area increases it, so the mark was lost.
✔ Gains credit: Human intervention restores the habitat or ecosystem and increases (changes) its biodiversity.
Start with the food supply: To explain a fall in wolves, students invented new predators, emigration or wolves competing with deer, rather than using the fact that wolves eat deer.
✔ Gains credit: The deer population fell, so there was less prey (food) for the wolves.
Name the species that gain and lose: General statements about 'competition' or 'predator–prey relationships' scored nothing when discussing the effect of a falling puffin population.
✔ Gains credit: Large gulls (puffin predators) decline; small fish increase; competition increases between gulls or fish but falls for other fish-eating species.
Mesh size, not net size: Students who wrote 'use different sized nets' as a fishing strategy lost the mark: a bigger net doesn't let young fish escape.
✔ Gains credit: Use nets with a larger mesh size, so smaller, younger fish escape and can breed.
Fish cross national borders: Asked why international agreements matter for fishing, about half wrote generally about extinction, biodiversity or food supply instead of focusing on fishing.
✔ Gains credit: Fish swim between countries' waters and much of the ocean doesn't belong to any one country.
Let trees fully regrow first: 'Allow trees to grow' was a common answer about sustainable clear felling, but it didn't score without saying the trees must reach full size before the next harvest.
✔ Gains credit: Replant the felled area and allow the new trees to grow fully before felling again (rotational or strip felling).
Ecotourism funds conservation: Many students had forgotten the term ecotourism, and some argued that building for tourists would raise biodiversity, which got no credit.
✔ Gains credit: Ecotourism: money from tourists is used to fund conservation, such as rewilding or reintroduction programmes.
Say why the habitat is fragile: Asked when preservation is necessary, many just named a place, such as the Galápagos Islands, without saying why.
✔ Gains credit: When a habitat is sensitive to damage, e.g. it holds a rare or endangered species.
Keep practising
Try the Ecosystems and Populations multiple choice quiz, the Biodiversity multiple choice quiz, the Ecosystems written quiz or the Biodiversity written quiz, or browse all our OCR A Level Biology quizzes. Our OCR A masterclasses (Year 12 on Wednesdays at 5.15pm, Year 13 on Tuesdays at 6.30pm) work through real exam questions on one topic each week.
Questions, mark schemes and examiners' report extracts © OCR.