Scientists reared beetle larvae with one of two inherited allele combinations. Each larva received either 15 mg or 30 mg of food per day. All other conditions were kept the same.
| Inherited allele combination | Food supplied per day in mg | Mean body mass after 20 days in mg |
|---|---|---|
| A | 15 | 82 |
| A | 30 | 106 |
| B | 15 | 94 |
| B | 30 | 121 |
Which conclusion is best supported by these results?
Allele combination and food supply both affected body mass, but food supply had the larger effect.
Only food supply affected body mass, because mean mass increased with more food for both combinations.
Allele combination and food supply both affected body mass, but allele combination had the larger effect.
Only allele combination affected body mass, because combination B had the greater mean mass at both food supplies.
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.