Normal hearing in humans is due to the dominant gene S, and hereditary deaf-mute is determined by the recessive

Normal hearing in humans is due to the dominant gene S, and hereditary deaf-mute is determined by the recessive gene s. From the marriage of a woman with normal hearing and a deaf-mute man, a deaf-mute child was born. Determine the genotypes of the parents.

Since the child is homozygous for this trait, we conclude that the mother is the carrier of the gene. Then the genotypes of the parents will be Ss (mother) and ss (father). To confirm, we will draw up a crossing scheme:

R: Ss x ss – a healthy mother, a carrier of the gene, and a sick father;

G: S, s x s – possible gametes;

F: Ss – 50% healthy child, carrier of the gene;

ss – 50% sick child.