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How to Calculate Allele Frequency

Allele Frequency Formula:

\[ p = \frac{n_A}{n_A + n_a} \]

1. What is Allele Frequency?

Definition: Allele frequency (p) measures how common a particular allele is in a population relative to other alleles for the same gene.

Purpose: It's fundamental in population genetics for understanding genetic variation and predicting evolutionary changes.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ p = \frac{n_A}{n_A + n_a} \]

Where:

  • \( p \) — Frequency of dominant allele (dimensionless, range 0-1)
  • \( n_A \) — Number of dominant alleles in population
  • \( n_a \) — Number of recessive alleles in population

Explanation: The frequency is calculated by dividing the count of dominant alleles by the total number of alleles (dominant + recessive).

3. Importance of Allele Frequency

Details: Understanding allele frequencies helps in studying genetic diversity, disease prevalence, and evolutionary biology.

4. Using the Calculator

Tips: Enter the number of dominant and recessive alleles observed in your population. Both values must be ≥ 0, and their sum must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does an allele frequency of 0.5 mean?
A: It means the dominant allele makes up 50% of all alleles for that gene in the population.

Q2: How do I count alleles in a population?
A: For diploid organisms, each individual has 2 alleles. Count all A alleles and a alleles across all individuals.

Q3: What's the frequency range for alleles?
A: Frequencies range from 0 (allele absent) to 1 (only allele present) in the population.

Q4: How is this different from genotype frequency?
A: Allele frequency counts individual alleles, while genotype frequency counts combinations (AA, Aa, aa).

Q5: Can I calculate recessive allele frequency with this?
A: Yes, recessive frequency (q) would be 1 - p (the dominant allele frequency).

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