One of the forms of retinitis pigmentosa is inherited as a recessive trait linked to the X chromosome

One of the forms of retinitis pigmentosa is inherited as a recessive trait linked to the X chromosome. A healthy woman whose father suffered from retinitis pigmentosa marries a healthy man. What offspring can be expected from a given married couple.

X (R) – norm, X (r) – retinitis pigmentosa.

Parents: (woman’s mother) X (R) X (R) × X (r) Y (woman’s father)

Gametes: X (R) X (r) Y

Presumptive children: X (R) X (r) healthy daughter, carrier of the disease, X (R) Y healthy son.

Parents: X (R) X (r) × X (R) Y

Gametes: X (R) X (r) X (R) Y

Prospective children: X (R) X (R) healthy daughter, X (R) Y healthy son, X (R) X (r) healthy daughter with retinitis, X (r) Y son with retinitis.