Question

A population has 1000 individuals. A PCR analysis of the genotypes of a gene associated with Lactase persistence are: LL = 450 Ll = 250 ll = 300. What are the allelic frequencies of the L and l alleles?

Answer 1

L allele: 0.575 (or 57.5%)

l allele: 0.425 (or 42.5 %)

Explanation:

Homo-zygous individuals have two copies of the same allele (i.e., either L alelle or l allele), while heterozygous individuals carry both alleles at a time (i.e., one L allele and one l allele). In consequence:

- Frequency of the L allele: [(450 x 2) + 250] / 2000 = 0.575

- Frequency of the l allele: [(300 x 2) + 250] / 2000 = 0.425