As we know the trait is caused by dominant alleles. III3 is not affected so she will have two recessice alleles so 2 lower case p.
III2 is affected so the person will have one dominant allele P and one recessive. The dominant is from the father and the recessive is from the mother.
1. Since it says the genetic disorder is caused by a dominant allele, that means that the ones affected (colored in) would have one "P" allele. Those not affected (not colored in) would display the genotype "pp." That would mean that generation III-3's genotype would be "pp."
2. The genotype of III-2 is "Pp." The dad was not affected (meaning he has 2 recessive alleles, pp) and the mom was affected (meaning she has at least 1 dominant allele, p; her genotype would either be PP or Pp). Because of this, III-2 would have to get one allele from the dad and one allele from the mom, therefore... their genotype would be: Pp.
