Question

The genetic inheritance of blue eye color in humans behaves a lot like a simple recessive trait, though in truth, eye color is actually controlled by multiple alleles. As a simple model, assume that eye color is controlled by a single gene, where the allele, B, for brown eyes is completely dominant over the allele, b, for blue eyes. Given that a population's dominant allele frequency, p, is twice the recessive allele frequency, q, what percent of the population will have brown eyes but will still carry the blue eye allele?

a) 44.4 percent
b) 11.1 percent
c) 22.2 percent
d) 88.8 percent

Answer 1

The correct answer is 22.2%

Step-by-step explanation:

Answer 2

`22.2\\` %

Step-by-step explanation:

As per Hardy-Weinberg equation, the sum of allele frequencies at locus is equal to one.

Let

`p = \\` dominant allele frequency

`q = \\` recessive allele frequency

`p + q = 1\\`...................... Eq (A)

Given,

Dominant allele frequency of population is twice the recessive allele frequency

Thus,

`p = 2 q\\`

Substituting this in equation A, we get -

`p + q = 1\\\\2q + q = 1\\3q = 1\\q = (1)/(3) \\q = 0.333\\p = 1 -q\\p = 1 -0.333\\p = 0.667\\q = 0.333\\`

Now we also know that

`p^2 + q^2 + 2pq = 1\\(0.667^2) + (0.333^2) + 2 pq = 1\\pq = 0.222\\`

≈
`22.2\\` %