A child has sickle-cell disease (ss) but neither parent is ill. What must be true of her parents’ genotypes? The father is heter
ozygous; the mother is normal. One parent has two recessive alleles. Both parents are heterozygous carriers. The mother is heterozygous; the father is normal.
Both parents are heterozygous carriers. Sickle Cell Anaemia is usually referred to as a recessive condition since an individual must have two copies of the sickle gene in order to have the disorder.
Since neither of the parents is ill, both of them must be heterozygous carriers for the child to have the disorder
