Question

There are five alleles of a particular gene in a population. The total number of different genotypes (for this allele) in the population will be

• A. 5
• B. 15
• C. 25
• D. 30

Answer 1

Answer: (B)

Consider the five alleles in the population to be A1, A2, A3, A4 and A5. An individual can have only two alleles at a time. So the various genotypes will be A1A1, A1A2, A1A3, A1A4, A1A5, A2A2, A2A3, A2A4, A2A5, A3A3, A3A4, A3A5, A4A4, A4A5, A5A5 (total 15). The general formula for types of genotypes is $\left[n\left(n+1\right)\right]/2,$ where n is the number of alleles in the population.