A grower released predatory beetles into one set of crop plots. The beetles feed on the crop pest. Another set of plots was left without beetles.
| Time after release (weeks) | Pest number per 100 plants, plots with beetles | Pest number per 100 plants, plots without beetles | Damaged leaves (%) with beetles | Damaged leaves (%) without beetles |
|---|---|---|---|---|
| 0 | 80 | 78 | 30 | 29 |
| 2 | 35 | 82 | 18 | 32 |
| 4 | 12 | 86 | 8 | 36 |
Use the data to explain whether releasing the predatory beetles was effective in reducing crop damage.
100 exam-style questions on Edexcel GCSE Biology 4.3 Selective breeding and genetic modification, covering 4.3.1 Selective breeding and its impact, 4.3.2 Tissue culture, 4.3.3 Genetic engineering overview, 4.3.4 Main stages of genetic engineering, 4.3.5 Advantages and disadvantages of GM organisms, 4.3.6 Agricultural solutions for a growing population, and 4.3.7 Evaluating genetic engineering and breeding. Each one has a worked solution and a mark scheme showing where the marks go.