Small reef fish shelter among the branches of living coral. They feed on small invertebrates that live on the coral.
A pathogen damages the coral on some reefs. Scientists add hollow blocks to provide shelter for fish on one of the damaged reefs.
The table shows the mean results after one year.
| Reef conditions | Living coral cover in % | Number of small invertebrates per m² | Number of small reef fish per 100 m² |
|---|---|---|---|
| No pathogen, no hollow blocks | 68 | 145 | 32 |
| Pathogen present, no hollow blocks | 21 | 48 | 11 |
| Pathogen present, hollow blocks added | 20 | 51 | 19 |
Evaluate the claim that adding hollow blocks completely prevents the pathogen from reducing the population of small reef fish.
82 exam-style questions on AQA GCSE Biology 7.1 Adaptations, interdependence and competition, covering 7.1.1 Communities, 7.1.2 Abiotic factors, 7.1.3 Biotic factors, and 7.1.4 Adaptations. Each one has a worked solution and a mark scheme showing where the marks go.