BIOLOGY TOP SCORE......Punnit Square Quesiton
Started by Toothguy80
You did that right! which shows that there are 2 boys not 1! yes 1 will die because of the lethal gene. If she gets pregnant 6 times then she can have 6 chidren. The probability of having a boy is 1/2. So then my guess would be that 3 out of 6 children will be boys. May be i dont understand the question.
I hope that helps!
Ok so sex linked genes are mostly seen in males because they only need 1 copy of the lethal gene to spontanously abort unlike females which need 2 of the genes.
So we have a heterozygous female (XcX) with a normal male (XY) so for the first cross we have
XcX XcY XX XY four children, 1 dies (the male XcY) leaving 3 children left
But the question says she has six children not 3 so you have to add another one of these crosses which means she has another set of
XcX XcY XX XY four children 1 died leaving 3 children
Now adding the two test crosses together you get 6 children with 2 normal male (XY) 2 normal female (XX) and 2 carrier females (XcX)
So the answer is she has 2 boys and 4 girls of the combined 6 children🙂
When seeing a genetic problem draw all the choices out it makes it much easier to see what the question is looking for.
So we have a heterozygous female (XcX) with a normal male (XY) so for the first cross we have
XcX XcY XX XY four children, 1 dies (the male XcY) leaving 3 children left
But the question says she has six children not 3 so you have to add another one of these crosses which means she has another set of
XcX XcY XX XY four children 1 died leaving 3 children
Now adding the two test crosses together you get 6 children with 2 normal male (XY) 2 normal female (XX) and 2 carrier females (XcX)
So the answer is she has 2 boys and 4 girls of the combined 6 children🙂
When seeing a genetic problem draw all the choices out it makes it much easier to see what the question is looking for.
