A student is comparing two case studies: Case I: A woman carries an X-linked recessive allele for a disorder. Her mate does not have the disorder. Case II: A man has an X-linked recessive disorder. His mate does not carry the allele for it. What can the student predict about the probable difference between the two case studies? A. Half of the boys in Case I will most likely have the disorder, whereas none of the boys in Case II will. B. Half of the girls in both Case I and Case II will most likely have the disorder. C. All of the girls in Case I will most likely be carriers of the disorder, whereas none of the girls in Case II will be carriers. D. All of the boys in both Case I and Case II will most likely have the disorder.

Explanation:

Case I.  XX* cross with male XY,

XX*× XY produce XX, XY, X*X, X*Y ( Half the boys have disorder and half of the girls are normal and half are carrier)

Case II.   X*Y cross with XX,

X*Y × XX   produce X*X, X*X, XY,XY ( All the boys are normal and all the girls are carrier).

So, the true statement is that, half of the boys in Case I will most likely have the disorder, whereas none of the boys in Case II will.

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most community's take hundreds of years to become stable