Answer:
1/4
Explanation:
1-Mother:
The probability to pass the disorder to her progeny is: 1 x 1/2 = 1/2
Father:
2-The probability to pass the disorder to his progeny is: 1 x 1/2 = 1/2
Therefore, the probability to have the disorder is equal to the product of both independent events, i.e., 1/2 x 1/2 = 1/4 or 25%