13. The answer is: C. 3/4 Let D be the dominant allele and d be the recessive allele. Since father and mother are both heterozygous: Dd x DdDdDDD (affected)Dd (affected)dDd (affected)dd (unaffected) Solution 13. The answer is: C. 3/4 Let D be the dominant allele and d be the recessive allele. Since father and mother are both heterozygous: Dd x DdDdDDD (affected)Dd (affected)dDd (affected)dd (unaffected).