Question

Peppered moths are dark-colored when they carry the dark (D) allele, and light-colored when they are homozygous for the recessive (d) allele.
A geneticist collected a population of 50 peppered moths, and found that 18 were dark (DD or Dd) and 32 were light (dd).
dd
DD or dd
O
Light form of
peppered moth
Dark form of
peppered moth
What are the allele frequencies for the alleles in this population? Assume that the conditions of Hardy-Weinberg equilibrium apply.
C A D=0.20; d = 0.80
C
B. D=0.50; d = 0.50
C
C
D = 0.25; d = 0.75
C
D
. D=0.36; d = 0.64

Answer 1

A D=0.20; d = 0.80

Explanation:

p² + 2pq + q² = 1

We find genetic frequency of the recessive gene then allelic frequency for the recessive alele;

q² = 32/50

q² = 0.64

q = 0.8

Allele frequencies of a gene add up to 1;

P + q = 1

p + 0.8 = 1

p = 1 – 0.8

p = 0.2