Scientists studied 500 mutations in the DNA of fruit flies.
The Figure shows the effect of these mutations on the phenotype of the fruit flies.
Figure

Use the Figure to give the percentage of mutations that had a small effect on the phenotype.
Calculate the number of mutations that had a significant effect on the phenotype.
Describe what the Figure shows about the effect of most mutations on the phenotype.
State how new alleles arise in a population.
40 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.