Question: In the MN-blood grouping system of a population, if the allele frequencies of M and N alleles are 0....

Question

In the MN-blood grouping system of a population, if the allele frequencies of M and N alleles are 0.6 and 0.4 respectively, the expected frequency of individuals bearing the MN-blood group is likely to be
(A) $48\%$
(B) $36\%$
(C) $16\%$
(D) $24\%$

Answer 1

Solution

The frequency of the individual is calculated with the help of the formula ${ 2pq }$ . The frequency of the group is calculated by the same formula just we have to multiply ${ 2pq }$ with the 100.

Complete answer:
GENE frequency, which is commonly known as allele frequency, is that the frequency of an allele ) at a specific locus during a population, which is expressed as a fraction or percentage. Specifically, it's the fraction of all chromosomes within the population that carry that allele. According to the Hardy–Weinberg principle, if the allele frequencies during a population with two alleles at a locus are p and q, then the expected genotype frequencies are p & q then the expected genotype frequencies are ${ p }^{ 2 }{, \ 2pq }{ \ and }{ \ q }^{ 2 }$ .
The Frequency of MN = ${ 2pq }$
${ = }{ 2 }{ \times }{ 0.6 }{ \times }{ 0.4 }$
Expected frequency of MN group ${ = }{ 2 }{ \times }{ 0.6 }{ \times }{ 0.4 }$ ) x 100 = $48\%$

Additional Information: The MN blood type in humans is rare and is under the control of a pair of codominant alleles, LM, and LN. Most of the people within the Inuit population are M/M, while this genotype is rare among Aborigines. They tend to possess other genotypes (N/N). The blood type MN is found to be under the control of an autosomal locus which was found on chromosome number four, with two alleles designated LM and LN. This type of blood group is just because of the glycoprotein present on the surface of red blood cells, which behaves like a native antigen. Frequencies of the 2 alleles vary widely among human populations.
So, the correct answer is ‘(a) $48\%$ ’.

Note: There are over 40 antigens within the MNSs blood type system. The two-variable genes that are referred to as GYPA and GYPB (glycophorin A and B, respectively) encodes the antigen.