Original application practice · 19 indicative marks

Ecological sampling: estimates and causation

Answer without the guided prompts, then review the science and working.

These are our practice questions and indicative marks, not examination-board questions or an awarded grade. The data are shared with guided practice; a case you have already studied is not an unseen test.

Context and data

Eight non-overlapping 0.50 m² quadrats were placed at randomly selected positions across a 2000 m² field. A plant count and soil-moisture reading were recorded at each position. The field boundary defines the sampling area.

Independent quadrat observations
QuadratPlant countSoil moisture / %
1220
2015
3535
4122
5432
6018
7330
8125

Five exam-condition questions

1. Estimate the total number of plants in the field.

3 indicative marks

2. Describe the relationship between soil moisture and plant abundance.

3 indicative marks

3. A student concludes that watering the field would produce the increase in plant abundance shown by the table. Evaluate this conclusion.

4 indicative marks

4. Describe how you would investigate the relationship between position down a slope and the abundance of this plant.

6 indicative marks

5. Suggest how the field abundance estimate could be improved. Explain how your change would help.

3 indicative marks

Print exam-condition questions · Print questions and guidance

Selected AQA 7402 connections: 3.4.6, 3.7.4. Use official papers for examination-board assessment.