Scientists investigated the spread of the rubella virus, which causes German measles. The first symptom is a distinctive red rash (spots) on the skin.
A group of 303030 children played together at a backyard party on Day 000. On the day of the party, one of the children developed a rubella rash.
Every two days after the party, scientists recorded how many of the other 292929 children first showed rubella spots. The results are shown in Table 1.
| Day when rubella spots first showed | Number of children |
|---|---|
| 6 | 0 |
| 8 | 0 |
| 10 | 0 |
| 12 | 2 |
| 14 | 3 |
| 16 | 8 |
| 18 | 5 |
| 20 | 1 |
| 22 | 0 |
| 24 | 0 |
| Total | 19 |
What was the range of days on which children first showed rubella spots? Use the data in Table 1.
From day ____________ to day ____________
Incubation time is the time from exposure to a pathogen until the first symptoms appear. Suggest the most likely incubation time for rubella based on this group.
Incubation time = ____________ days
Suggest one reason why some of the children at the party did not develop rubella.
25 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.