A veterinary laboratory compared two vaccination schedules against virus V.
Ten rabbits were given each schedule.
The table shows the mean concentration of antibodies against virus V in each group. After the blood sample at week 12, every rabbit was exposed to the same quantity of live virus V.
| Group | Mean antibody concentration at week 0 in mg/dm³ | Mean antibody concentration at week 4 in mg/dm³ | Mean antibody concentration at week 6 in mg/dm³ | Mean antibody concentration at week 12 in mg/dm³ | Number of rabbits that became ill |
|---|---|---|---|---|---|
| P | 0 | 18 | 12 | 3 | 8 |
| Q | 0 | 19 | 74 | 31 | 1 |
Describe how the mean antibody concentrations changed in groups P and Q during the 12 weeks.
Explain why the results support using schedule Q rather than schedule P to protect rabbits against virus V.
Virus W has surface antigens with different shapes from those of virus V. Explain why schedule Q would not be expected to protect the rabbits against virus W.
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.