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Q33 - Genotype and Phenotype Frequencies at a Three-Allele Locus

Theoretical B Real exam question - full text reproduced under IBO's CC BY-NC-SA 4.0 license

In a single locus with three alleles A, B and C, the population allele frequency of A is 0.25 and the frequency of AC individuals is 0.20. We assume random mating in the population.

Using the information and data, determine which of the statements are true or which are false.

A. The frequency of the AA genotype will be 0.1875
B. The frequency of the AB genotype will be 0.175
C. If B is dominant to A and C, then the frequency of the B phenotype will be the frequency of the B allele
D. In a single locus with 5 alleles, we get 16 possible genotypes

Question reproduced from IBO 2015, Theoretical Exam B, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)