Question

A colorblind man married a normal woman. Their daughter who was phenotypically normal, married a normal man, and the couple had three kids – a normal boy, a color-blind boy, and a color-blind girl with Turner syndrome. Where does the non-disjunction occur?

Select one:

a. Allosome non-disjucntion during anaphase post-fertilization

b. Allosome non-disjunction during anaphase I in the father

c. Allosome non-disjunction during anaphase II in the mother

d. X chromosome loss due to a translocation

e. A and C

Answer 1

Answer will be d option loss of X chromosome dur to translocation in case of male

So let us see crossing from start

XX x. X​​​​​​C​​​​​Y

I

XY. XX​​​​​C​

Now carrier female marry to normal male

XX​​​​​C​ X XY

I

X. X​​​​​​C. Female gamete while only Y from male as X chromosome loss dur to translocation from male

X. X​​​​​​C. Y. O

I

XO. XY. X ​​​​C Y. X​​​​​​C​​​O

So normal male, color blindness male and Turner female formed.hope it's clear..thanks