A breeder wants wheat with short stems and a high yield. The table shows offspring from a cross.
Table
| Plant | Stem height / cm | Grain yield / g |
|---|---|---|
| P | 65 | 36 |
| Q | 90 | 45 |
| R | 68 | 40 |
| S | 82 | 43 |
The breeder selects two plants with stems shorter than 70 cm.
Which action is most likely to improve both characteristics over several generations?
Cross P with R, then repeatedly select short offspring with high yields.
Cross Q with S, then repeatedly select short offspring with high yields.
Cross Q with S, then repeatedly select offspring without measuring height.
Cross P with R, then repeatedly select offspring without measuring yield.
44 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.