A fruit grower investigated variation in the mass of apples. The grower used genetically identical trees of genotype J and genetically identical trees of genotype K. Equal numbers of each genotype received either 20 litres or 40 litres of water each week. All other growing conditions were kept the same.
The table shows the mean mass of one apple at harvest.
| Apple-tree genotype | Mean apple mass with 20 litres of water per week in g | Mean apple mass with 40 litres of water per week in g |
|---|---|---|
| J | 151 | 158 |
| K | 195 | 202 |
Explain whether water supply or inherited alleles had the greater effect on apple mass in this investigation.
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.