Question

Among 86 Indians from Central America, the frequencies of M and N were 0.74 and 0.26 respectively. Calculate the expected percentages of individuals with M, Mn and N type Blood? (I dont get this at all)

Answer 1

M=74%
N=26%

74% of 86= 63.64 indians who have blood type M (genotype MM)
26% of 86= 22.36 indians who have blood type N (genotype NN)

You can think of 3 Genotypes.

MM= blood type M
NN= blood type N
MN= blood type MN

So NN+MM is always MN since 1 allele from both parents is taken
MN+MM could be MM and MN
NN+NN would be NN so blood type N

with 74% being genotype MM and 26% NN you can say
100% of the offspring would be blood type MN since there are no heterozygous genotypes in the P generation.