A student proposes that left-handedness is a recessive trait that is therefore hidden in much of the human population.A survey of a class of 36 students finds that 27 (0.75)are right-handed and 9 (0.25)are left-handed.Using the Hardy-Weinberg formula,what would the expected genotype and allele frequencies be in this theoretical population?
A)0.75 right-handed homozygous dominant and 0.25 recessive homozygous for 3-to-1 right- to left-handed alleles in the population
B)0.25 right-handed homozygous,0.50 heterozygous,and 0.25 recessive homozygous for a 3-to-1 right- to left-handed alleles in the population
C)0.25 right-handed homozygous,0.50 heterozygous,and 0.25 recessive homozygous for a 0.5 allele frequency for each allele
D)0.50 right-handed homozygous,0.25 heterozygous,and 0.25 recessive homozygous for a 0.5 allele frequency for each allele
E)They cannot be estimated using these limited data.

Question

Quizplus · Accepted Answer

The Hardy-Weinberg principle states that allele frequencies in a population remain constant from generation to generation in the absence of other evolutionary influences. Given that 25% of the population is left-handed (recessive homozygous), the allele frequency for the recessive allele is the square root of 0.25, which is 0.5. Therefore, the frequency of the dominant allele is also 0.5. Using the formula p^2 + 2pq + q^2 = 1, where p and q are the frequencies of the dominant and recessive alleles respectively, the expected genotype frequencies are 0.25 (right-handed homozygous), 0.50 (heterozygous), and 0.25 (recessive homozygous).

A Student Proposes That Left-Handedness Is a Recessive Trait That