What does allele frequency refer to in genetics?

Allele frequency is a fundamental concept in genetics that refers to how often a particular allele appears in a gene pool of a population. It is expressed as a fraction or percentage of all alleles for that gene in the population. This measurement helps researchers understand genetic diversity, population structure, and the evolutionary dynamics of a species.

For example, if we consider a population of flowering plants with a specific gene that has two alleles (A and a), the allele frequency indicates the proportion of allele A relative to the total number of alleles for that gene in the population. If allele A appears 70 times and allele a appears 30 times in a population of 100 individuals, the frequency of allele A is 0.70, while the frequency of allele a is 0.30.

Understanding allele frequency is crucial for studying mechanisms such as natural selection, genetic drift, and gene flow, as shifts in these frequencies can indicate how populations evolve over time.

Other options, like the total number of genes in a population or the appearance of specific traits, focus on different aspects of genetics and do not accurately define allele frequency. Only the correct answer captures the concept of how frequent a genetic variation is within the gene pool, emphasizing its importance in genetic studies and