Two animal rescue centres care for animals of the same species. At each centre, one animal infected with the same communicable disease mixed with the other animals. The table shows vaccination data and the new cases recorded during the next three weeks.
| Rescue centre | Animals vaccinated (%) | Number of unvaccinated animals | New cases among unvaccinated animals |
|---|---|---|---|
| N | 90 | 15 | 2 |
| S | 60 | 40 | 24 |
Calculate the percentage of unvaccinated animals that became new cases at each rescue centre.
Explain how the difference in the percentage of animals vaccinated could account for the answers to part (a).
252 exam-style questions on AQA GCSE Biology 3.1 Communicable diseases, covering 3.1.1 Communicable (infectious) diseases, 3.1.2 Viral diseases, 3.1.3 Bacterial diseases, 3.1.4 Fungal diseases, 3.1.5 Protist diseases, 3.1.6 Human defence systems, 3.1.7 Vaccination, 3.1.8 Antibiotics and painkillers, and 3.1.9 Discovery and development of drugs. Each one has a worked solution and a mark scheme showing where the marks go.