Question

. If a woman is a carrier for colorblindness (XcX) has a child with a man who is colorblind (XcY) can they have a colorblind female? Show your work.

Answer 1

So I did a punnet square and my results are XcXc, XXc, XcY, and XY. so yes there is possibility they could have a colorblind female (XcXc).

Answer 2

Ans.

Colorblindness is a sex-linked, recessive genetic disorder that results in inaccurate and limited color perception in affected people.

Females carry two X chromosomes and presence of one normal X chromosome can hide the effect of other mutated X chromosome (Xc) as it is a recessive trait.

So, females with both mutated X chromosomes (Xc) are diseased, while females with one normal and one mutated chromosome are unaffected and carrier for the disease.

Males carry only one X chromosome, so, all males with mutated X chromosomes (Xc) are diseased. Cross between a carrier woman and a colorblind man will give following progeny:

Parents: XcX (female) x XcY (male)

↓

Gametes: Xc & X Xc & Y

↓

Progeny: XcXc XXc XcY XY

Normal (carrier) female: 25% (XXc)

Colorblind female: 25% (XcXc)

Normal male: 25% (XY)

Colorblind male: 25% (XcY)

Thus, 'a carrier women and a colorblind man can have a colorblind female.'