Explain that female carriers are heterozygous for X-linked recessive alleles.

·      An individual with a recessive allele for a disease condition that is masked by a normal dominant allele is said to be a carrier

·      Carriers are heterozygous and can potentially pass the trait on to the next generation, but do not suffer from the defective condition themselves

·      Females can be carriers for X-linked recessive conditions because they have two X chromosomes - males (XY) cannot be carriers