Question

For the $MN$-blood group system, the frequencies of $M$ and $N$ alleles are $0.7$ and $0.3$, respectively. The expected frequency of $MN$-blood group bearing organisms is likely to be

• A. $42$%
• B. $49$%
• C. $9$%
• D. $58$%

Answer 1

The correct option is A $42$%

From the equation (a+b)${}^2$ = a${}^2$=b${}^2$=2ab = 1

MN = 2ab

MN = 2x0.7x0.3

expected frequency of MN-blood group = 2x0.7x0.3/1x100 = 42%.

So the correct option is '42%'.