Harry's Family
Harry was raised by his mothers sister, Petunia Dursley. She, unlike Lily, did not receive two pairs of the recessive wizarding allele. Although she does not have two pairs of the recessive allele it is very possible that she could have one pair.
Lily received both of the recessive Alleles, and therefore became a witch.
If Petunia received the heterozygous pair of alleles, what would the probability be for her son Dudley to be a carrier for the recessive wizard allele? (Assuming that Vernon is homozygous dominant)
If Petunia received the heterozygous pair of alleles, what would the probability be for her son Dudley to be a carrier for the recessive wizard allele? (Assuming that Vernon is homozygous dominant)