Allele frequency is the frequency (proportion) of alleles in a population. It can be expressed as a percentage or a decimal.
For example, suppose a population has 10 individuals and there are two alleles (A and a) of a gene. Suppose the individuals are as follows:
4 AA individuals = 8 A alleles
4 Aa individuals = 4 A alleles and 4 a alleles
2 aa individuals = 4 a alleles
So there are (8 + 4) = 12 A alleles in the population and (4 + 4) = 8 a alleles in the population.
The frequency of A alleles is therefore 12/20 = 0.6 or 60%.
The frequency of a alleles is 8/20 = 0.4 or 40%.
(Notice that the total number of alleles equals 1.0 or 100%.)
one off the pea plants mates more than the others
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