Question

In studying the gene pool of a population, you find that 15% of the population is homozygous recessive (tt) for a trait. How would you use this information to solve for the frequency of the dominant T allele?

Answer 1

Answer:$61$ %

Explanation:

As per HARDY-WEINBERG LAW

$p^2 + 2pq + q^2 = 1 \\p + q = 1$

$p =$ represents the frequency of the dominant allele in the population

$q =$represents the frequency of the recessive allele in the population

$p^2 =$represents the percentage of homozygous dominant individuals

$q^2 =$represents the percentage of homozygous recessive individuals

$2pq =$represents the percentage of heterozygous individuals

Here the frequency of ‘tt” allele is $0.15$

Thus, $p^2 = 0.15\\p = \sqrt{0.15}\\p = 0.387$

Substituting this in below given equation, we get -

$0.387 + q = 1\\q = 1 - 0.387 \\q = 0.613$

Frequency of T allele is represented by q.

Thus, frequency of T allele would be $0.613\\= 61 %$%

Answer 2

Because we know that 15% of the population does not have the allele we can assume that at least 85% of the population has at least on copy of the dominant allele.