The allele Xh X^h\,Xh causes a recessive condition and XH X^H\,XH is the normal allele. In one family, an affected man has an unaffected daughter. The daughter has children with an unaffected man.
Explain what the daughter’s genotype must be.
Calculate the probability that a child of the daughter will be affected, and the probability that a son of the daughter will be affected.
71 exam-style questions on Edexcel GCSE Biology 3.3 Inheritance, covering 3.3.1 Gregor Mendel and the basis of genetics, 3.3.2 Alleles and inherited characteristics, 3.3.3 Monohybrid inheritance, 3.3.4 Determination of sex at fertilisation, 3.3.5 Outcomes from monohybrid crosses, 3.3.6 Inheritance of ABO blood groups, 3.3.7 Inheritance of sex-linked disorders, and 3.3.8 Multiple genes and phenotypic features. Each one has a worked solution and a mark scheme showing where the marks go.