Human ABO blood groups are controlled by a single gene with three alleles IA, IB

Question

Human ABO blood groups are controlled by a single gene with three alleles IA, IB, and i. The three alleles contribute to four blood group phenotypes. In addition to the ABO blood groups, there are two other loci that control blood phenotypes, the MN blood group locus and the Rh factor locus. The MN blood group has two codominant alleles, LM and LN. The Rh factor locus also has two alleles, Rh and Rh-, where Rh is dominant. The two phenotypes at the Rh factor locus are Rh and Rh-. Suppose in a population, the frequency of the ABO allele IA is 0.36, and the IB allele frequency is 0.26. In the same population, the frequency of the LM allele is 0.47, and the frequency of the Rh is 0.62. What is the frequency of the genotype IAIB LMLM Rh-Rh- if the population is in Hardy–Weinberg equilibrium?

Explanation / Answer

The frequency of the ABO allele IA is 0.36, and the IB allele frequency is 0.26.

lets suppose allelic frequencies of IA=p, IB=q and i=r

we have p+q+r=1 if this follow the Hardy-Weinberg Theorem

p² +q²+r² +2pq +2pr +2qr =1,

IAIB frequency would be 2pq =2x0.36x0.26=0.27

For blood group MN if LM is p and LN is q, LM is given 0.47

LMLM would be p2 that is 0.47x0.47=0.22

Now for Rh the frequency 0.62 given denotes the Rh+Rh+ (p2) and Rh+Rh- (2pq)

so Rh-Rh-(q2) would be 1-0.62=0.38

Blood O A B AB Frequency r p+2pr q+2qr 2pq

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.