SOLUTION: Red-green colorblindness in humans is sex-linked and recessive. A colorblind man (jack) marries a normal woman (mary) whose mother was colorblind. Jack and Mary produce a son who i

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Question 169072: Red-green colorblindness in humans is sex-linked and recessive. A colorblind man (jack) marries a normal woman (mary) whose mother was colorblind. Jack and Mary produce a son who is colorblind and a normal daughter. The genotypes of the 5 individuals involved are:
Answer by 303795(602) About Me  (Show Source):
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The gene for the colourblindness is carried on the X chromosome.
As males only have one X chromosome they only need to have the gene on the one X chromosome for colour blindness to be displayed.
Females have two X chromosomes. As colour blindness is recessive then they need to have it on both of the X chromosomes.
I am using X for normal vision and x for colourblind vision
Jack has the genotype xY (He is colourblind)
Mary's mum has the genotype xx (She is colourblind)
Mary has the genotype Xx (The normal gene from her father and the colourblindness gene from her mother)
Son has the genotype xY (he is colourblind. The colourblindness gene came from Mary)
Daughter has the genotype xX (The colourblindness gene from Jack and the normal gene from Mary.)