Scientists investigated new cases of Salmonella infection among people who ate at two workplace canteens during one month.
In canteen P, the same chopping boards were used to prepare raw poultry and salad. In canteen Q, separate chopping boards were used.
| Canteen | Number of people who ate at the canteen | Number of new cases of Salmonella infection |
|---|---|---|
| P | 800 | 12 |
| Q | 1800 | 9 |
Calculate the incidence of Salmonella infection per 100 000 people for each canteen.
A scientist concluded that using the same chopping boards for raw poultry and salad caused the difference in incidence between the two canteens.
Evaluate the scientist's conclusion.
181 exam-style questions on OCR GCSE Biology 6.3 Monitoring and maintaining health, covering 6.3.1 Health and disease, 6.3.2 Interactions between diseases, 6.3.3 Spread of communicable diseases, 6.3.4 Common infections and diseases, 6.3.5 Physical plant defence responses, 6.3.6 Chemical plant defence responses, 6.3.7 Detecting and identifying plant diseases, 6.3.8 White blood cells and platelets, 6.3.9 Non-specific defence systems, 6.3.10 The immune system, 6.3.11 Monoclonal antibodies, 6.3.12 Vaccines and medicines, 6.3.13 Aseptic techniques, 6.3.14 Discovery and development of new medicines, 6.3.15 Causes of non-communicable diseases, 6.3.16 Treatments for cardiovascular disease, 6.3.17 Lifestyle factors and non-communicable diseases, 6.3.18 Cancer, 6.3.19 Stem cells in medicine, 6.3.20 Gene technology in medicine, and 6.3.21 The human genome and medicine. Each one has a worked solution and a mark scheme showing where the marks go.