Question

What is the genotype and phenotype of a female carrier of haemophilia?

Options

• Xh Xh; Affected

• XH XH; Normal

• XH Xh; Carrier (normal phenotype)

• Xh Y; Affected male

Answer 1

A female carrier of haemophilia has the genotype XH Xh, meaning she possesses one normal allele and one defective allele. Because the normal allele is dominant, carrier females display a normal phenotype but can pass the defective allele to their offspring.