AQA · A-Level · Biology
Course version: 7402 · Version from Sept 2016
Students should be able to: show understanding of the need to manage the…
Full specification wording
Populations in ecosystems (A-level only): Students should be able to: show understanding of the need to manage the conflict between human needs and conservation in order to maintain the sustainability of natural resources evaluate evidence and data concerning issues relating to the conservation of species and habitats and consider conflicting evidence use given data to calculate the size of a population estimated using the mark-release-recapture method.
Conservation maintains natural resources sustainably but often conflicts with human needs like food, timber, and housing.
Checked against the AQA 7402 specification (opens in a new tab) on .
- Point 13 of 14
- 4 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
Conservation maintains natural resources sustainably but often conflicts with human needs like food, timber, and housing. Managing this requires sustainable practices like coppicing or fishing quotas. When evaluating conservation data, identify evidence both supporting and opposing a claim, alongside limitations like small sample sizes. Population size is estimated using mark-release-recapture. The formula is: Estimated population = (Number in first sample × Number in second sample) / Number marked in second sample. For example, if 20 are marked, and a second sample of 30 contains 5 marked individuals, the estimate is (20 × 30) / 5 = 120. This assumes no births, deaths, or migration.
What earns the marks
- State a point supporting the claim, quoting specific data from the provided source.
- State a point against the claim, quoting specific data, to provide a balanced evaluation.
- Identify a limitation of the evidence, such as the absence of a control, limited sample size, or lack of a statistical test.
- Name a sustainable practice, such as selective felling, coppicing, fishing quotas, or ecotourism.
- Identify the specific human need conflicting with conservation, such as agriculture, timber, or employment.
- Calculate population size using the mark-release-recapture formula and state an assumption, such as no migration or no loss of marks.
Common mistakes and how to put them right
Answering an evaluate question with supporting points only.
Put it right: Provide evidence both for and against the claim.
Stating that results are significant or not significant without context.
Put it right: Specify what differs, the direction of the difference, and reference a statistical test if provided.
Treating standard deviation as a statistical test.
Put it right: Standard deviation shows the spread of data around the mean, whereas a statistical test determines the probability that a difference is due to chance.
Describing conservation as stopping all human use.
Put it right: Define conservation as managing human use sustainably.
Exam tips
- Set out evaluate answers under 'For' and 'Against' headings to ensure both sides are covered before adding data limitations.
- Write out the mark-release-recapture formula before calculating, and always round the final answer to a whole number of organisms.
Try the lesson
The start of the Populations in ecosystems (A-level only): Students should be able to: show understanding of the need to manage the conflict between human needs and conservation in order to maintain the sustainability of natural resources evaluate evidence and data concerning issues relating to the conservation of species and habitats and consider conflicting evidence use given data to calculate the size of a population estimated using the mark-release-recapture method. lesson, made from checked teaching notes for this specification point.
Have a go first
A conservation group estimated the size of a population of dormice in a woodland using the mark-release-recapture method. In the first sample, 30 dormice were caught, marked and released. Two days later, a second sample of 40 dormice was caught, of which 8 were marked. A few days later, a third sample of 40 dormice was caught, of which 4 were marked. Use the mean number of marked dormice and the sample size of 40 to estimate the population size.
Listen
Conservation maintains natural resources sustainably but often conflicts with human needs like food, timber, and housing. Managing this requires sustainable practices like coppicing or fishing quotas. When evaluating conservation data, identify evidence both supporting and opposing a claim, alongside limitations like small sample sizes. Population size is estimated using mark-release-recapture. The formula is: Estimated population = (Number in first sample × Number in second sample) / Number marked in second sample. For example, if 20 are marked, and a second sample of 30 contains 5 marked individuals, the estimate is (20 × 30) / 5 = 120. This assumes no births, deaths, or migration. A strong answer earns marks for these points. State a point supporting the claim, quoting specific data from the provided source. State a point against the claim, quoting specific data, to provide a balanced evaluation. Identify a limitation of the evidence, such as the absence of a control, limited sample size, or lack of a statistical test. Name a sustainable practice, such as selective felling, coppicing, fishing quotas, or ecotourism. A common slip: Answering an evaluate question with supporting points only. Instead, provide evidence both for and against the claim. Exam tip: Set out evaluate answers under 'For' and 'Against' headings to ensure both sides are covered before adding data limitations.
Key words
Say what each word means before you turn the card.
sustainability
Try answering aloud or in your head before turning the card.
conflicting human needs
Try answering aloud or in your head before turning the card.
evaluating evidence
Try answering aloud or in your head before turning the card.
mark-release-recapture calculation
Try answering aloud or in your head before turning the card.
See every definition
- sustainability
- Managing the use of natural resources so that they are maintained, which conservation aims to achieve.
- conflicting human needs
- Human needs such as food, timber and housing that often conflict with conservation, so managing the conflict is required.
- evaluating evidence
- Considering evidence and data on conservation issues, including evidence both supporting and opposing a claim and conflicting evidence.
- mark-release-recapture calculation
- Using given data in the formula (number in first sample × number in second sample) divided by number marked in second sample to estimate population size.
There is more to this lesson
The full lesson goes on to check your understanding and help you earn the marks. Create a free account to carry on, with your progress saved.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge
Test your understanding of Populations in ecosystems (A-level only): Students should be able to: show understanding of the need to manage the conflict between human needs and conservation in order to maintain the sustainability of natural resources evaluate evidence and data concerning issues relating to the conservation of species and habitats and consider conflicting evidence use given data to calculate the size of a population estimated using the mark-release-recapture method.
Active recall beats re-reading. Take an instant quiz now to test what you’ve learned and lock it into long-term memory.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge