Young mice of the same species have genotype R or genotype S. Mice of each genotype are fed either a lower-energy diet or a higher-energy diet for four weeks, with all other conditions controlled. The table shows the mean body mass of each group after four weeks.
| Genotype | Mean body mass on lower-energy diet / g | Mean body mass on higher-energy diet / g |
|---|---|---|
| R | 21.4 | 26.8 |
| S | 24.1 | 30.2 |
Which pair of results shows the effect of genotype on mean body mass?
Genotype R on the lower-energy diet (21.4 g) and genotype S on the higher-energy diet (30.2 g)
Genotype R on the higher-energy diet (26.8 g) and genotype S on the higher-energy diet (30.2 g)
Genotype R on the lower-energy diet (21.4 g) and genotype R on the higher-energy diet (26.8 g)
Genotype S on the lower-energy diet (24.1 g) and genotype R on the higher-energy diet (26.8 g)
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.