Scientists exposed samples from two generations of a fruit fly population to the same period of heat stress. The table shows the mortality in each sample.
| Generation | Mortality (%) |
|---|---|
| 1 | 75 |
| 10 | 48 |
By generation 10, mortality had fallen. Calculate this fall as a percentage of the mortality in generation 1. Give your answer as a whole number.
85 exam-style questions on Edexcel GCSE Biology 4.1 Evolution and natural selection, covering 4.1.1 Work of Darwin and Wallace and 4.1.2 Resistant organisms and evolution. Each one has a worked solution and a mark scheme showing where the marks go.