Question

Please help !!!!

will all of the female children be carriers of the color - blind allele , or will none be carriers ?






Will all of the male children be color blind ? or will none be color blind ?




and complete the punnet square ..

Answer 1

The punnett square

Colorblind Man's genotype = XbY

Non colorblind Woman's genotype = XX

Xb Y

X XbX XY

X XbX XY

All the female children will be carriers of color-blind allele (XbX).

None of the male children will be color blind (XY).

Explanation: Color blindness is an X-linked disorder in which one is unable to distinguish between some colours. It is usually borne on the X-chromosome thus X-linked disease. Usually males are sufferers because they have only one X chromosome (XY) and women are mostly carriers because they have two X chromosome and rarely does it affect the two X chromosomes in female.

If Xb is the allele for color blindness, and X and Y represent chromosomes that are not affected, a cross between a color blind man (XbY) and a woman who is not color blind (XX) as shown in the punnett square above will produce two females who are carriers (XbX) of color blind allele and two males who are not color blind.

See the attached punnet square for more information