How can we calculate the frequency of a specific genotype in a population?

• A. By counting the number of individuals with the genotype and dividing by the total population size
• B. By analyzing the environmental factors affecting the population
• C. By measuring the phenotypic traits associated with the genotype
• D. By using the Hardy-Weinberg equation

Answer: (D)

Verified step by step guidance

1. Understand the Hardy-Weinberg principle, which states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of evolutionary influences.
2. Identify the alleles involved in the genotype you are interested in. For example, if you are looking at a genotype 'Aa', identify the alleles 'A' and 'a'.
3. Use the Hardy-Weinberg equation: \( p^2 + 2pq + q^2 = 1 \), where \( p \) is the frequency of the dominant allele and \( q \) is the frequency of the recessive allele.
4. Determine the allele frequencies \( p \) and \( q \) in the population. This can be done if you know the frequency of homozygous dominant (\( p^2 \)), homozygous recessive (\( q^2 \)), or heterozygous (\( 2pq \)) individuals.
5. Calculate the frequency of the specific genotype using the appropriate term from the Hardy-Weinberg equation. For example, for the heterozygous genotype 'Aa', use \( 2pq \).