Researchers at a horticulture college assessed the movement of rose black spot between plants in a propagation house. Each of three separate bays contained one rose plant with rose black spot and 20 healthy rose plants. The same light, temperature and number of plants were used in each bay. The only differences were the irrigation system and the use of a fan shown in the table.
After 14 days, the researchers recorded the number of healthy plants that had developed rose black spot.
| Bay | Irrigation system | Fan arrangement | Number of healthy plants with rose black spot |
|---|---|---|---|
| A | Fine mist released above the plants | No fan | 15 out of 20 |
| B | Water released at the base of each plant | No fan | 3 out of 20 |
| C | Water released at the base of each plant | Air moved from the infected plant towards the healthy plants | 11 out of 20 |
Explain which irrigation system and fan arrangement should be used to reduce the spread of rose black spot in the propagation house. Use all the data in the table.
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.