Scientists genetically modify a cereal crop by inserting an allele that increases drought tolerance. A related wild grass growing near the crop can be pollinated by the cereal plants.
The scientists produce four lines of the GM cereal and collect these results.
| GM cereal line | Plants surviving after 14 days without water (%) | Pollen grains that are viable (%) |
|---|---|---|
| P | 88 | 82 |
| Q | 35 | 3 |
| R | 86 | 6 |
| S | 92 | 79 |
Suggest which GM cereal line should be grown to maintain drought tolerance while reducing the risk that the inserted allele spreads to the wild grass. Explain your answer.
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.