Suppose variants at a single locus affect wing length in a species of crickets, with homozygotes for the L allele having long wings, homozygotes for the l allele having short wings, and heterozygotes having wings of intermediate length.In one population of 600 individuals, 400 have long wings, 160 have intermediate-length wings, and 40 have short wings.Is there an excess or a deficiency of heterozygotes in the population with respect to Hardy-Weinberg equilibrium? By how many individuals?
A) An excess of 64 individuals
B) An excess of 32 individuals
C) An excess of 16 individuals
D) A deficiency of 16 individuals
E) A deficiency of 32 individuals

Question

Quizplus · Accepted Answer

To determine if the population is in Hardy-Weinberg equilibrium, we can use the following equation:
p^2 + 2pq + q^2 = 1
where p is the frequency of the L allele and q is the frequency of the l allele. 
From the information given, we can calculate the allele frequencies: 
p^2 = 400/600 = 2/3
q^2 = 40/600 = 1/15
2pq = 160/600 = 4/15
Using these values, we can calculate the expected frequencies of each genotype: 
LL = p^2 = (2/3)^2 = 4/9
Ll = 2pq = 8/45
ll = q^2 = (1/15)^2 = 1/225
We can now compare the expected and observed frequencies of heterozygotes: 
Expected frequency of heterozygotes = 8/45 * 600 = 106.67
Observed frequency of heterozygotes = 160
There is a deficiency of heterozygotes, as observed frequency is lower than the expected frequency. 
The difference between the expected and observed frequency of heterozygotes is: 
|Expected - Observed| = |106.67 - 160| = 53.33, which is approximately 32 individuals. Therefore, the answer is E, a deficiency of 32 individuals.

Suppose Variants at a Single Locus Affect Wing Length in a Species