Question

In a certain population of rabbits, the allele for brown fur is dominant over the allele for white fur. If 20 out of 100 rabbits have white fur, what is the allele frequency for the recessive allele? The Hardy-Weinberg equation is: [homozygous dominant]2 + 2[heterozygous] + [homozygous recessive]2 = 1

Answer 1

I believe it gives you the answer. It should be one fifth or 20%. #TeamAlvaxic

Answer 2

The Hardy-Weinberg equation is

p2 + 2pq + q2 = 1 and p + q = 1

p = frequency of the dominant allele in the population

q = frequency of the recessive allele in the population

p2 = percentage of homozygous dominant individuals

q2 = percentage of homozygous recessive individuals

2pq = percentage of heterozygous individuals

Here in this question, 20 out of 100 rabbits have white fur which means that the % of homozygous recessive individuals is  

= 20/100 = 0.2

q2 = percentage of homozygous recessive individuals = 0.2

q = square root of 0.2

q = 0.44 = frequency of the recessive allele in the population = 44%