Answer:
The probability of having a disorder is 50 %.
Explanation:
The offspring has that genetic disorder if the Sarah who is phenotypically normal with no family history and tom has a genetic disorder so there is 50 percent chance that the children of Sarah and tom has that genetic disorder. if the disorder linked with Y chromosome of male so this disorder is present in the sons but if the disorder linked with X chromosome of male so this disorder is present in the daughters.
