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

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.

Answer 2

Answer:
`61\\` %

Step-by-step 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 = √(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 %\\`%