A colorblind male (XcY) married to a normal (XX) female produces an F1 offspring with a normal son (XY) and a colorblind carrier daughter (XcX). Intermarriage between the F1 offspring results in 1 normal son, 2 normal daughters and 1 color-blind son in the F2 progeny.
here,
Genotype XcY of a color blind male
A normal female has a genotype of XX
The first progeny is F1 and the second progeny is F2
Parents : ♂ × ♀
Phenotype: Normal color blindness
Genotype : XcY XX
Gamit : (Xc) (Y) (X) (X)
F1 progeny : XcX XY
(carrier daughter) (natural son)
Svanishek : F1×F1
Parents : ♂ × ♀
Phenotype: Normal carrier
Genotype : XY XcX
Gamit : (X) (Y) (Xc) (X) )
F2 progeny (checker board)
Comment: From the checker board, out of 4 children, 1 normal son, 2 normal daughters and 1 color blind son. Color blindness requires one Xc gene in males and two Xc genes in females.
Phenotypic ratio : Normal son : Normal daughter : Color blind son = 1 : 2 : 1