Question

Sally is pregnant and worried that she might be Rh incompatible with her

unborn child after remembering what she learned in her high school
biology class. Sally knows she is Rh negative (the recessive phenotype) and
her husband is Rh positive, but is heterozygous. What chance do they have
of their potential child being Rh positive?

Answer 1

The Rh- allele is recessive. So sally is Rh-Rh- and her husband is Rh+Rh-.

The possible genotypes for Punnet's square are: Rh+/-,Rh+/-,Rh-/-,Rh-/-

So the chance to have an Rh+ child is 50%