This is how much a certain genotype occurs in the population.<\/p>\n\n\n\n
For example, let us take the gene ‘B’ for black hair. Those with BB and Bb have black hair, those with bb have blonde hair. In a certain population, the following numbers were taken;<\/p>\n\n\n\n
Homozygous dominant(BB): 234<\/p>\n\n\n\n
Heterozygous(Bb): 132<\/p>\n\n\n\n
Homozygous recessive(bb): 43<\/p>\n\n\n\n
Total: 409<\/p>\n\n\n\n
The genotypic frequency for BB is 234\/409=0.5721<\/p>\n\n\n\n
The genotypic frequency for Bb is 132\/409=0-3227<\/p>\n\n\n\n
The genotypic frequency for bb is 43\/409=0.1051<\/p>\n\n\n<\/span>\n This is how much a certain allele occurs in the population.<\/p>\n\n\n\n We will reference the previous example. If 234 people have genotype BB, it means that each of these people has two copies of the allele ‘B’. Therefore in total, these 234 people have 468 ‘B’ alleles.<\/p>\n\n\n\n If 132 people have genotype Bb, it means that they each have one copy of ‘B’ and another of ‘b’. Therefore in total, they have 132 ‘B’ alleles and 132 ‘b’ alleles.<\/p>\n\n\n\n If 43 people have genotype bb, it means that they each have two copies of ‘b’. Therefore in total, they have 86 ‘b’ alleles. In total, there are 468+132+132+86= 818 alleles.<\/p>\n\n\n\n The allelic frequency for ‘B’ is (468+132)\/818=0.7334<\/p>\n\n\n\n The allelic frequency for ‘b’ is (132+86)\/818=0.2665<\/p>\n\n\n<\/span>\n The Hardy-Weinberg law states that the allelic and genotypic frequencies will always be constant and equal to one<\/strong> in a population as long as certain requirements are met such as no immigration, no mutations, and a large population with random matings.<\/p>\n\n\n\n As no realistic population can fulfill all these requirements, the Hardy-Weinberg law usually refers to an ideal, virtual population.<\/p>\n\n\n\n According to the Hardy-Weinberg law,<\/p>\n\n\n\nAllelic frequencies<\/h4>\n<\/span>\n\n\n
The Hardy-Weinberg Law<\/h3>\n<\/span>\n\n\n