What is gene frequency?

What is gene frequency?

• A. Frequency of alleles at a locus
• B. Frequency of genotypes at the locus
• C. Rate of mutation
• D. Proportion of individuals with a trait

Answer: (A)

Allele frequency is the proportion of copies of a given allele at a genetic locus in a population. In a diploid species, there are two alleles per individual, so the total number of allele copies is twice the number of individuals. To find the frequency, count how many times the allele appears among all copies and divide by the total number of alleles. For example, in a population of 10 individuals, if there are 12 copies of allele A and 8 copies of allele a, the frequency of A is 12/20 = 0.6 and the frequency of a is 0.4. This differs from the proportion of individuals with a particular genotype or phenotype, and from the mutation rate. Under Hardy-Weinberg assumptions, genotype frequencies (AA, Aa, aa) relate to allele frequencies, but the fundamental quantity being described here is the allele (gene) frequency.

Allele frequency is the proportion of copies of a given allele at a genetic locus in a population. In a diploid species, there are two alleles per individual, so the total number of allele copies is twice the number of individuals. To find the frequency, count how many times the allele appears among all copies and divide by the total number of alleles. For example, in a population of 10 individuals, if there are 12 copies of allele A and 8 copies of allele a, the frequency of A is 12/20 = 0.6 and the frequency of a is 0.4. This differs from the proportion of individuals with a particular genotype or phenotype, and from the mutation rate. Under Hardy-Weinberg assumptions, genotype frequencies (AA, Aa, aa) relate to allele frequencies, but the fundamental quantity being described here is the allele (gene) frequency.