A population of insects reproduces asexually. Each offspring inherits its parent's resistance or susceptibility to a pesticide. The table describes one generation.
| Insect type | Number before spraying | Percentage surviving spraying | Offspring produced per survivor |
|---|---|---|---|
| Resistant | 200 | 60 | 2 |
| Susceptible | 800 | 15 | 4 |
All survivors reproduce and then die. No mutation or migration occurs.
What percentage of the new generation is resistant, and how does this compare with the population before spraying?
50.0%; resistance has increased from its original frequency of 20.0%.
33.3%; resistance has decreased from its original frequency of 50.0%.
33.3%; resistance has increased from its original frequency of 20.0%.
50.0%; resistance has decreased from its original frequency of 60.0%.
44 exam-style questions on AQA GCSE Biology 6.2 Variation and evolution, covering 6.2.1 Variation, 6.2.2 Evolution, 6.2.3 Selective breeding, 6.2.4 Genetic engineering, and 6.2.5 Cloning. Each one has a worked solution and a mark scheme showing where the marks go.