A sample of 500 field mice contains 225 individuals that are D₁D₁, 175 that are D₁D₂, and 100 that are D₂D₂. What are the frequencies of D₁ and D₂ in this sample?

Verified step by step guidance

1. Calculate the total number of alleles in the population by multiplying the number of individuals by 2, since each individual has two alleles. For 500 mice, the total number of alleles is 500 * 2.
2. Determine the number of D₁ alleles: Each D₁D₁ individual contributes 2 D₁ alleles, and each D₁D₂ individual contributes 1 D₁ allele. Calculate the total number of D₁ alleles using the formula: (2 * number of D₁D₁ individuals) + (1 * number of D₁D₂ individuals).
3. Determine the number of D₂ alleles: Each D₂D₂ individual contributes 2 D₂ alleles, and each D₁D₂ individual contributes 1 D₂ allele. Calculate the total number of D₂ alleles using the formula: (2 * number of D₂D₂ individuals) + (1 * number of D₁D₂ individuals).
4. Calculate the frequency of the D₁ allele by dividing the total number of D₁ alleles by the total number of alleles in the population.
5. Calculate the frequency of the D₂ allele by dividing the total number of D₂ alleles by the total number of alleles in the population.

Key Concepts

Genotype Frequencies

Genotype frequencies refer to the proportion of different genotypes within a population. In this case, the genotypes D₁D₁, D₁D₂, and D₂D₂ represent different combinations of alleles for a specific gene. Understanding these frequencies is essential for calculating allele frequencies, as they provide the necessary data on how many individuals possess each genotype.

Allele Frequencies

Allele frequencies indicate how common an allele is in a population. They are calculated by dividing the number of copies of a specific allele by the total number of alleles for that gene in the population. In this scenario, the frequencies of alleles D₁ and D₂ can be derived from the genotype frequencies, allowing for insights into genetic diversity and population structure.

Hardy-Weinberg Principle

The Hardy-Weinberg Principle provides a mathematical framework for understanding genetic variation in a population at equilibrium. It states that allele and genotype frequencies will remain constant from generation to generation in the absence of evolutionary influences. This principle is useful for predicting expected genotype frequencies based on allele frequencies, which can help verify if a population is in genetic equilibrium.