The quantity of eletrophoretic genotypes for the Mdh locus were foundin a human
ID: 260677 • Letter: T
Question
The quantity of eletrophoretic genotypes for the Mdh locus were foundin a human population. The numbers 1 and 2 in the table below represent two different alleles
Genotypes (numbers)
locus 1/1 1/2 2/2
width 620 10 370
.a.Calculate the genotypic and allelic frequencies.
b.Assuming random mating, calculate the expected number of heterozygotes at the Mdh locus.
c.Is this population in HWE at the Mdhlocus? How could you tell?
d.What is one probable reason why the population would be out of HWbased on the result?
Explanation / Answer
Q) The number 1 and 2 represents two different alleles, 1 seems dominant and allele 2 is recessive.
The genotypes and the observed numbers are :-
Total number of observed individuals = 1/1 + 1/2 + 2/2 = 620+10+370 = 1000.
Phenotype frequency --
As each parent has two alleles, so the total number of alleles is twice the population.
here total population is 1000 , so as two alleles each parent carries so the total no. of alleles is 1000 * 2= 2000.
and heterozygous individuals carry one of each allele .
considering these two factors .
No. of 1 alleles = p = f(1) = [(620*2)+10] / 2000 = 1250 / 2000 = 0.625
No. of 2 alleles = q = f(2) = [ ( 370* 2) +10 ] / 2000 = 750 / 2000 = 0.375
Q a )
Genotype frequency will be
f (1/1) = p2 = f(1) * f (1) = (0.625 )* (0.625) = 0.390
f ( 1 / 2 ) = 2pq = 2 * f (1) * f (2) =( 0.625) *( 0 .375) = 0.468
f (2 / 2) = q 2 = ( 0.375 ) * ( 0.375) = 0.140
Calculation of allelic frequency is
p = allelic frequency of f (1) = 1250 /2000 = 0.625
Q = allelic frequency of f(2)= 750 /2000 = 0.375
So P +Q = 0.625 + 0.375 = 1
Q b ) Assuming random mating, calculate the expected number of heterozygotes at the Mdh locus.
The expected numbers of heterozygotes would be
Homozygous dominant is f (1/1) = p2 * total no. of population
0.390 * 1000 = 390.62 = 391
Heterozygous expected number will be f (1/2)= 2 pq * 1000 = 0.468* 1000 = 468.75= 469
Hemozygous recessive number will be f(2/2) = q2 * 1000 = 0.140*1000= 140
Qc) Is this population in HWE at the Mdhlocus? How could you tell?
The population is not in HWequilibrium at Mdh locus because the observed value and expected values do not match .
Q d) .What is one probable reason why the population would be out of HWbased on the result
The probable reason behind the population not being in HW equilibrium is may be due to the population size, or the manner by which the population suddenly chnaged.
Because a population remains in HW equilibrium if there is no migration, no mutation, no genetic drift , infinitely large population. a deviation from this leads to imbalnce in HW equilibrium.
Genotypes Total number observed 1/1 620 1/2 10 2/2 370Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.