Answer:
50%
Explanation:
i'm going to do a punnet square below. so the man has 1 x-chromosome and 1 y-chromosome but i'll capitalize his x because color deficiency is on the x chromosome. the woman is xx and both lower case because she is not a carrier
woman
x x
X Xx Xx
y xy xy
Because the environment is faster then the squrrel has to find stuff for the nest and a safe spot
If they are both carriers , we can create a cross with Rr.
The probability of not even carrying PKU is 1/4 or 25%
The probability of carrying is 2/4 or 50%
And the probability of inheriting the disease PKU is 1/4 , 25%