This is my interpretation of it
The woman carries a sex linked lethal gene
soo..
the father is normal
the mother has to be a carrier otherwise she wud be dead
XY with XcX (c is denoted as the gene)
we get XXc, XX, XcY, and XY
rite?
Ok so..it says she has six children
just look at what we have so far, one of her sons is dead, the 3rd one XcY.
So now if she had four kids, she wud have 1 son, XY and 2 girls
In order for her to have 6 kids, you wud have to do two punnet squares, in order to see which kids survived and which died.. so do this cross twice, (two sets of 4 kids)
So we would have another set of kids just like the first one (XXc, XX, XcY, and XY), but theres only 6 total surviving because the boy that is XcY dies also like in the first case.
6 kids, only 2 of which are boys
