Question

The human MN blood type is determined by two codominant alleles, L(M) and L(N). The frequency of L(M) in Eskimos on a small Arctic island is 0.80.

(a) If random mating takes place in this population, what are the expected frequencies of the M, MN, and N blood types on the island?

(b) If the inbreeding coefficient for this population is 0.05, what are the expected frequencies of the M,MN,and N blood type on the island

Answer 1

(a) Frequency of M = 0.64

Frequency of N = 0.04

Frequency of MN= 0.32

(b) Expected frequencies of M = 0.648

Expected frequencies of MN = 0.304

Expected frequencies of N = 0.048

Step-by-step explanation:

(a) If random mating takes place in the population, then the expected frequencies are

f(L(M)) = p = 0.8

F(L(N)) = q

q= 1 - p

= 1 - 0.8

= 0.2

Frequency of M = p^2 = ( 0.8)^2 = 0.64

Frequency of N = q^2 = (1-p)^2 = (1 - 0.8)^2 = (0.2)^2 = 0.04

Frequency of MN = 2pq = 2 * 0.8 * 0.2 = 0.32

(b)

F = inbreeding coefficient = 0.05

f(L(M)L(M)) = p^2 + Fpq = (0.8)^2 + 0.05 * 0.8 * 0.2 = 0.648

f(L(M)L(N)) = 2 pq - 2Fpq = 2 * 0.8 * 0.2 - ( 2 * 0.05 * 0.8 * 0.2) = 0.304

f(L(N)L(N)) = q^2 + Fpq = (0.2)^2 + ( 0.05 * 0.8 * 0.2) = 0.048