Remember: the D allele causes pigment production but the d allele does not. If at least one dark allele is present then pigment will be produced, so moths that are homozygous DD or heterozygous Dd genotypes are dark. Only moths that are homozygous dd are light. Predict how the frequency of alleles changed after the Industrial Revolution. The frequency of D allele increased. The frequency of d allele increased. .

1. Remember: the D allele causes pigment production but the d allele does not. If at least one dark
allele is present then pigment will be produced, so moths that are homozygous DD or
heterozygous Dd genotypes are dark. Only moths that are homozygous dd are light. Predict how
the frequency of alleles changed after the Industrial Revolution. The frequency of D allele
increased. The frequency of d allele increased.