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?
a. 0.3
b. 0.9
c. 0.18
d. 0.36

The correct answer is-

a. 0.3

Explanation-

As per the question, the frequency of blue eyes (which is a recessive trait) is 0.09.

Let us consider the genotype for it be 'qq' ( q representing recessive allele) that produces blue eyes.

According to equation of Hardy Weinberg principle-

p²+ 2pq+ q² = 1

where p² represent the genotype for dominant trait and q² is the genotype for recessive trait.

p represents frequency of dominant allele and q is recessive allele frequency.

q² =  0.09

q = √0.09

  =  0.3

Thus, option a) 0.3 is the right answer.

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.