Question

biobuddy socrative question
peppered moths have two morphs, coded for by a two - allele, dominant/recessive system: a dominant dark morph (carbonaria) and a recessive light morph (typica). a sampled moth population exhibits 33% of the typica morph. assuming hardy - weinberg equilibrium, what proportion of the population is probably heterozygous (aa) for this trait?
a) 0.49
b) 0.33
c) 0.51
d) 0.67

Explanation:

Step1: Identify the frequency of the recessive phenotype

The frequency of the light - morph (tyypica, recessive phenotype) is given as $q^{2}=0.33$.

Step2: Calculate the frequency of the recessive allele $q$

Take the square - root of $q^{2}$. So, $q = \sqrt{0.33}\approx0.574$.

Step3: Calculate the frequency of the dominant allele $p$

Since $p + q=1$ in the Hardy - Weinberg equilibrium, then $p = 1 - q=1 - 0.574 = 0.426$.

Step4: Calculate the frequency of the heterozygous genotype

The frequency of the heterozygous genotype $Aa$ is $2pq$. Substitute the values of $p$ and $q$: $2\times0.426\times0.574 = 2\times0.244 = 0.488\approx0.49$.

Answer:

A. 0.49