Question

color blindness is an x-linked recessive trait. if a color-blind male marries a normal, homozygous female, what are the possible genotypes and phenotypes of the children?

Answer 1

Colour blind male means X'Y
Nomal femal means XX

on crossing you get : 2 X'X ; 2 XY

Genotypes (phenotypes) : 2 XY (normal male) and 2 X'X (carrier female with no colourblindness)

Answer 2

genotype of Colour blind male-$X^{0} Y$

Genotype of normal homozygous female-$X^{+} X^{+}$

The offspring produced will be

$2X^{+} Y$ and $2 X^{+} X^{0}$

$2X^{+} Y$-normal vision boy (50%)

$2 X^{+} X^{0}$- heterozygous normal vision girl -(50%). They are called carriers.