Two strains of mouse belong to the same species but have different inherited alleles. The mice within each strain are genetically identical. All conditions are kept the same except for the food supply.
| Strain | mean body mass with low food supply in g | mean body mass with high food supply in g |
|---|---|---|
| P | 21.0 | 29.0 |
| Q | 24.0 | 28.0 |
A student concludes that food supply is the only cause of the differences in body mass.
Evaluate this conclusion using 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.