Question

I'LL MAKE YOU BAINLIEST IF YOU ANSWER

Suppose a mother is a carrier for an X-linked recessive disorder such as hemophilia. Complete the Punnett square to model the heritability of this trait. Then, answer the question below.


1. What are the chances of a female carrier being born from these parents?



A.

0%


B.

25%


C.

75%


D.

100%

Answer 1

The answer should be b 25%

Answer 2

25%

Step-by-step explanation:

If we don't have any information about the father's genotype, we have to make two different Punnett squares with the genotypes available. He can either be dominant or recessive, so the options are X^a or X^A. When we set up the Punnett square, we put Xa and XA for the mom's genotype and Xa for the dads genotype (since we're looking for females, we don't write his Y alleles) For that Punnett square, we get 1/2 or 50%. But, there's still another possible genotype for the dad, XA. So now we make another Punnett square with XA as dad and XA Xa for the mom. We again get 1/2 or 50%. If you have two different fractions for the probability, or likelihood of an event occurring, you multiply them together! So 1/2 times 1/2 is 1/4!

If we do know the dad's genotype, let me know because then I messed this up. Hope this helped, it helped me for my test on it tomorrow!