How likely is a color blind son to be born in a woman with normal vision, but whose father and husband are color blind?
May 29, 2020 | Education
| A woman with normal vision XDXd, because her father is color blind – meaning his XdY genotype. A woman gets gamete Xd from him.
The woman’s husband is color blind – his XdY genotype.
We make a crossing scheme:
P (women) XDXd → (husband) XdY
A woman forms two types of gametes: XD; Xd
A man forms two types of gametes: Xd; Y
Possible genotypes and phenotypes of children:
HDX – a girl with normal vision (carrier)
XDY – a boy with normal vision
XdXd – color blind girl
XdY – color blind boy
The probability of having a color blind son is 25%
