Question

Suppose the frequencies of two alleles in a particular population are B = 0.67 and b = 0.33. The genotypic frequencies are BB = 0.50, Bb = 0.35, and bb = 0.15. Do these numbers indicate inbreeding? Explain why or why not

Answer 1

Inbreedingis the mating ofgeneticaly related species,the allelic frequency oi 8= 0.67,b= 0.33. Consider the a leles 8=p,b=qof a population,when there isinbreeding the Genotype frequency can becalculated using the formula,

For homozygous normal inividuals the genotypic frequency of BBis equals to p1+fPq .   For heterozygous normal individuals the genotypic frequency of Bbis equals to 2pq{ l-f). For homozygous recessive individuals the genotypic frequency of bbis equals to q +fPq .

\/\there f is the measure of genotypic frequency deviation from the Hardy-/\-einberg equation,its

value ranges from -1to +1.For inbreeding the j value is greater than zero,so in this way genotypic frequency affected due to inbreeding.

Consider the f value as 0.25,and then the genotypicfrequency BB value canbe calculated,

Bil •(0.67)1 + (0.25)(0.67}(0.33)

= 0.50

The genotypic frequency Sbvalue canbe calculated,

Bb = 2(0.67)(0.33)(1-0.25)

•0.37

The genotypic frequency bbvalue canbe calcu ated,

bb •(0.33)' + (0.25)(0.67)(0.33)

= 0.13

These numbers suggest the inbreeding because the calculated genotypic frequency coincides with the given values.