A population of plants contains inherited differences in resistance to a disease. The disease is present over several generations. Scientists record the number of resistant plants in samples from the population.
| Generation | Number of resistant plants | Total number of plants sampled |
|---|---|---|
| 1 | 18 | 120 |
| 4 | 72 | 120 |
Calculate the percentage of plants that were resistant in generation 1 and generation 4.
Explain the change in the proportion of resistant plants and predict how it is likely to change in the next generation if the disease remains present.
122 exam-style questions on OCR GCSE Biology 5.2 Natural selection and evolution, covering 5.2.1 Genetic variation within a population, 5.2.2 Developments in classification systems, 5.2.3 How evolution occurs through natural selection, 5.2.4 Evolution as change over time, 5.2.5 Evidence for evolution, and 5.2.6 Darwin and Wallace. Each one has a worked solution and a mark scheme showing where the marks go.