A breeder used selective breeding over many generations to produce a new strain of laying hen. Hens from both strains were kept under the same conditions.
| Strain of laying hen | Mean number of eggs produced per hen per year |
|---|---|
| Original strain | 240 |
| Selectively bred strain | 300 |
Calculate how much higher, as a percentage of the original strain, the mean annual egg production is for the selectively bred strain.
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.