Human blood types are, in part, determined by the ABO system. The allele frequency for blood type IA is 0.3, and IB is 0.1. What is the frequency of the allele that codes for no carbohydrate (type O) and is designated i?

0.6

Explanation:

The ABO system for blood type is determined by a gene with multiple alleles. This means that even though any single individual can have at most two different alleles, in the population there are 3 different alleles in existence: IA, IB and i.

The sum of the frequencies of all the alleles in a population must add up to 1, therefore

freq (IA) + freq (IB) + freq (i)=1

0.3 + 0.1 + freq (i) = 1

freq (i) = 1 - 0.3 - 0.1

freq (i) = 0.6