In a population of 400 salamanders, some individuals have long toes and others have short toes.This phenotypic difference is due to a single gene with dominant and recessive alleles, T and t, where T confers long toes.If the toe length gene is in Hardy Weinberg equilibrium, and 256 individuals have short toes, how many individuals are heterozygous at the toe length locus?
A)More information is needed to determine the answer.
B)32
C)128
D)144

Question

Quizplus · Accepted Answer

In Hardy-Weinberg equilibrium, the frequency of the recessive phenotype (short toes, tt) is q^2. Given 256 individuals have short toes, q^2 = 256/400 = 0.64, so q = 0.8. Therefore, p = 1 - q = 0.2. The frequency of heterozygotes (Tt) is 2pq = 2(0.2)(0.8) = 0.32. Thus, the number of heterozygous individuals is 0.32 * 400 = 128.

In a Population of 400 Salamanders, Some Individuals Have Long