A student investigates the effect of trampling by walkers on the density of clover plants in a grassy country park.
She uses a quadrat to sample the vegetation from two areas in the park.
She counts the number of clover plants in multiple quadrats in each area.
The table below shows her results:
| Area | Average (mean) number of clover plants per m2\text{m}^2m2 |
|---|---|
| Footpath (trampled) | 3 |
| Away from footpath (untrampled) | 124 |
Name the independent variable in this investigation.
Suggest an explanation for these results.
Suggest how the student made sure that her results were valid and reliable.
The student claims that all footpaths in the park should be paved with asphalt to prevent soil and plant damage.
Discuss the advantages and disadvantages of paving footpaths in natural parks.
44 exam-style questions on Edexcel IGCSE Biology Human influences on the environment. Each one has a worked solution and a mark scheme showing where the marks go.