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

(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

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