A rehoming centre recorded cases of a communicable disease in dogs. The disease can spread when dogs make direct contact.
The centre introduced a policy of moving infected dogs to a separate kennel block. The table shows data from equal 20-day periods before and after the policy was introduced. Other hygiene procedures remained the same.
| Policy | Number of uninfected dogs at the start | Number of these dogs that developed the disease |
|---|---|---|
| Infected dogs remained in the shared kennel block | 75 | 18 |
| Infected dogs were moved to a separate kennel block | 125 | 10 |
Explain why the centre should continue to isolate infected dogs. Use calculations based on the data.
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.