for sickle-cell diease, assume S is the dominant allel and s the recessive allele. Which genotypes are possible for offspring of a carrier (Ss) and a person who lacks the sickle-cell allele (SS)?
The genotypes possible for the offspring are SS, Ss, SS, and Ss. Therefore, there is a 50% chance that one of the offspring is a carrier, and a 0% chance that one of the offspring has sickle-cell disease itself.
