How to solve this genetics exercise?
In a population in balance people with MN genotype are 3 times more than those with group NN. Find frequency p(LM) and q(LN)
- hcbiochemLv 74 weeks ago
Let frequency of NN = x, and frequency of MN = 3x.
From the Hardy-Weinberg equation,
x = q^2 and
3x = 2pq
Also, you know that p = 1-q, so 3q^2 = 2(1-q)q
Factoring out q gives: 3q = 2-2q
5q = 2
q = 0.4
p = 1-q = 0.6
So, the frequency of LM (p) = 0.6 and frequency of LN(q) = 0.4
This all works since q^2 = 0.16 and 2pq = 2(0.6)(0.4) = 0.48 = 3x.
There may well be a different way to get to this answer, but this is how I saw it.