A vaccine is being developed to protect sheep against a viral disease. The vaccine contains only antigen K.
The table shows the antigen on each strain of the virus.
| Virus strain | Antigen |
|---|---|
| P | K |
| Q | L |
| R | M |
Scientists measured the concentration of antibodies in the blood that attached to each antigen.
| Antigen | Antibody concentration before vaccination in µg/cm³ | Antibody concentration 21 days after vaccination in µg/cm³ |
|---|---|---|
| K | 1.8 | 64.2 |
| L | 2.1 | 2.3 |
| M | 1.6 | 1.7 |
Explain which strain of the virus the vaccine is most likely to protect against and why the vaccine is unlikely to protect against the other two strains.
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.