Plants of species Q grow on a sports ground, from open ground towards the shaded side of a pavilion. Students want to investigate whether the abundance of species Q is associated with light intensity.
The students have started this plan:
The students recorded these results. The mean abundance column is incomplete.
| Distance along tape (m) | Light intensity (lux) | Count of species Q, transect 1 | Count of species Q, transect 2 | Mean count of species Q |
|---|---|---|---|---|
| 0 | 8200 | 8 | 10 | |
| 4 | 6100 | 7 | 9 | |
| 8 | 3900 | 3 | 5 | |
| 12 | 2100 | 2 | 4 |
Describe how the students should complete and use their results to decide whether the abundance of species Q is associated with light intensity. You should include how to process the counts, what pattern the results show, whether the results prove that light intensity causes the difference in abundance, and one way to improve the investigation.
82 exam-style questions on Edexcel GCSE Biology 9.1 Ecosystems and interdependence, covering 9.1.1 Levels of organisation in ecosystems, 9.1.2 Abiotic and biotic factors, 9.1.3 Importance of interdependence, 9.1.4 Parasitism and mutualism, and 9.1.5 Determining number of organisms in an area. Each one has a worked solution and a mark scheme showing where the marks go.