Q18

The occurrence of a genetic disease in a family resulting from the presence of a dominant allele is shown. 1 2 KEY Affected male Unaffected male 3 4 5 Affected female Unaffected female If the disease has arisen as a result of a mutation, which of the following is the most likely cause of the disease in this family?
A. A germ-line mutation in individual 2
B. A germ-line mutation in individual 4
C. A somatic mutation in individuals 1 and 2
D. A somatic mutation in individuals 4 and 5