Fill in the blank.
Duchenne muscular dystrophy is caused by an X-linked recessivemutation in the DMD gene, which encodes the protein dystrophin. Afemale without the disease mates with a male with Duchenne musculardystrophy; they have two sons and two daughters. The first son hasthe disease as does their first daughter.
Based on this, the probability that the second son will have thedisease is________________
The probability that the second daughter will be a carrieris____________
