Question 1
A population is in Hardy-Weinberg equilibrium. The gene of interest has two alleles, with 16% of the population portraying the features of the recessive phenotype. What percentage of the population is heterozygous?
Explanation: Using the Hardy-Weinberg equilibrium equations, you can determine the answer.
The value of 
gives us the frequency of the dominant allele, while the value of 
gives us the frequency of the recessive allele. The second equation corresponds to genotypes. 
is the homozygous dominant frequency, 
is the heterozygous frequency, and 
is the homozygous recessive frequency.
16% of the population shows the recessive phenotype, and therefore must carry the homozygous recessive genotype. We can use this information to solve for the recessive allele frequency.
We can use the value of 
and the first Hardy-Weinberg equation to solve for 
.
Knowing both 
and 
, you can use the second equation to find the percent of heterozygous organisms in the population.
The value of gives us the frequency of the dominant allele, while the value of gives us the frequency of the recessive allele. The second equation corresponds to genotypes. is the homozygous dominant frequency, is the heterozygous frequency, and is the homozygous recessive frequency.
16% of the population shows the recessive phenotype, and therefore must carry the homozygous recessive genotype. We can use this information to solve for the recessive allele frequency.
We can use the value of and the first Hardy-Weinberg equation to solve for .
Knowing both and , you can use the second equation to find the percent of heterozygous organisms in the population.