One parent is homozygous for a recessive allele and one parent is heterozygous for a recessive allele in an autosomal dominant genetic disorder. what is the chance that a child of those two parents will have the disorder?

It seems that you have missed the necessary options for us to answer this question so I had to look for it. Anyway, here is the answer. If one parent is homozygous for a recessive allele and one parent is heterozygous for a recessive allele in an autosomal dominant genetic disorder, the chance that a child of those two parents will have the disorder is 75%. Hope this helps.