Scientists investigate young fish of the same species from two genetic lines. All the fish within each line are genetically identical, but line P and line Q have different alleles.
Fish from each line are given either a low food ration or a high food ration for six weeks. All other conditions are kept the same.
| Genetic line | Mean body mass with low food ration in g | Mean body mass with high food ration in g |
|---|---|---|
| P | 12.4 | 17.1 |
| Q | 14.8 | 20.6 |
Explain the pattern in the results.
96 exam-style questions on Edexcel GCSE Biology 3.4 Variation and the Human Genome Project, covering 3.4.1 Causes of variation, 3.4.2 Outcomes of the Human Genome Project, 3.4.3 Genetic variation within a population, and 3.4.4 Effects of genetic mutations on phenotype. Each one has a worked solution and a mark scheme showing where the marks go.