Question

In a particular population, the allele frequency of the ABO blood type alleles are as follows: IA is 10%, IB is 50%, and i is 40%.

A) IA is recessive
B) IAIB is the most common genotype
C) IAIB is the least common genotype
D) ii is the most common genotype

Answer 1

Using allele frequencies, we can determine that the most common genotype in the population is IBIB and that IAIB is not the least common but rather IAIA, while ii is more common than both IAIA and IAIB but not the most common overall.

Step-by-step explanation:

In the given population, where the allele frequencies are 10% for IA, 50% for IB, and 40% for i, we can assess the possible genotypes and their commonality. The allele i is recessive, while both IA and IB are dominant. To find the prevalence of a particular genotype, you would multiply the frequencies of the contributing alleles together. Therefore, the most common genotype would be IBIB since IB is the most frequent allele at 50%. The genotype IAIB would be less common as you would multiply the frequencies of IA and IB together, resulting in a frequency of 5% (0.10 * 0.50). The least common genotype would involve the least frequent allele, which is IA, in a homozygous state, which is IAIA at a frequency of 1% (0.10 * 0.10). Consequently, the genotype ii would have a frequency of 16% (0.40 * 0.40), making it not the most common genotype but more common than IAIA or IAIB. Based on this information, the correct answer would be:

C) IAIB is the least common genotype.