Question

A woman discovers that her family has a history of a rare, X-linked genetic disorder that causes symptoms late in life. Her mother and father didn’t have the disease, but all three of her brothers do. What is the probability that the woman will have the disease as well?

A. 100%
B. 75%
C. 50%
D. 25%
E. 0%

Answer 1

50%

explanation: the mother has two x’s and the father has an xy so the sons got an affected x from the mother, and a y from the father. the woman could get either x from the mother (affected or not) and the x from the father (unaffected since the father didn’t have the disease)