Polydactyly is caused by a dominant allele, D. A man who is heterozygous for polydactyly has children with a woman who does not have polydactyly.
Give the genotype of the woman.
Draw a genetic diagram to show the genotypes of the possible children of this couple. Identify the phenotype of each genotype.
Give the probability that a child of this couple will have polydactyly.
The couple's first child does not have polydactyly. Explain the probability that their second child will have polydactyly.
76 exam-style questions on AQA GCSE Biology 6.1 Reproduction, covering 6.1.1 Sexual and asexual reproduction, 6.1.2 Meiosis, 6.1.3 Advantages and disadvantages of sexual and asexual reproduction, 6.1.4 DNA and the genome, 6.1.5 DNA structure, 6.1.6 Genetic inheritance, 6.1.7 Inherited disorders, and 6.1.8 Sex determination. Each one has a worked solution and a mark scheme showing where the marks go.