AGB 121: Principles of Animal Genetics and Population Genetics (2+1)

GENOTYPE FREQUENCY

• Genotype frequency is the proportion of a population that has one genotype relative to all genotypes at a specific locus.
• For example: Two alleles are possible - A or a, that can combine to give the following genotypes AA (homozygous dominant), Aa (heterozygous), aa (homozygous recessive).

Genotype	No. of individuals	Genotype frequency
AA	60	f(AA) = 60/200 = 0.3 or 30%
Aa	100	f(Aa) = 100/200 = 0.5 or 50%
aa	40	f(aa) = 40/200 = 0.2 or 20%
Total	200	=1.0 or 100%