Question

In a population of humans, the frequency of blue eyes is 0.09. If having blue eyes is the recessive phenotype, what is the frequency of the recessive allele?
0.3
0.9
0.18
0.36

Answer 1

If you assume that the population is in Hardy-Weinberg equilibrium, then you can use the Hardy-Weinberg equations. That would make the frequency of the homozygous recessive (blue eyes) equal to q-squared.

If q-squared = 0.09. The q is the square root of that, which is 0.3. And q is the frequency of the recessive allele for blue eyes.

Answer 2

so the answer would be a?

Answer 3

Yes, but if you are going to be tested on this, be sure you understand the H-W equations for genotype frequencies and for allele frequencies.