Two similar lakes are monitored before and after a fish farm is established in lake X. Lake Y has no fish farm. The table shows the number of native fish species recorded using the same method.
Table
| Lake | Before | After |
|---|---|---|
| X | 12 | 7 |
| Y | 12 | 11 |
Which conclusion is best supported?
The farm caused all five species losses, because lake X lost five species.
The farm had no possible effect, because lake Y also lost one species.
The farm may have contributed, because the decline was greater in lake X.
The farm increased biodiversity, because seven species remained in lake X.
38 exam-style questions on Edexcel GCSE Biology 9.2 Energy transfer and biodiversity, covering 9.2.1 Energy transfer between trophic levels, 9.2.2 Efficiency of energy transfers, 9.2.3 Human interactions and biodiversity, 9.2.4 Benefits of maintaining biodiversity, and 9.2.5 Biological factors affecting food security. Each one has a worked solution and a mark scheme showing where the marks go.