On a rocky shore, seaweed makes its own food by photosynthesis. Limpets eat seaweed, and herring gulls eat shore crabs.
A disease affected the limpet population. Scientists recorded the only food item found in the stomach of each of 50 shore crabs before and after the disease.
| Time | Crabs containing seaweed | Crabs containing limpet remains |
|---|---|---|
| Before the disease | 29 | 21 |
| After the disease | 50 | 0 |
Using the data, explain how the disease changed the consumer role of the herring gull.
83 exam-style questions on AQA GCSE Biology 7.2 Organisation of an ecosystem, covering 7.2.1 Levels of organisation, 7.2.2 How materials are cycled, 7.2.3 Decomposition, and 7.2.4 Impact of environmental change (HT only). Each one has a worked solution and a mark scheme showing where the marks go.