In a hardy-Weinberg population, if gene has only two alleles A and a, and the gene frequency of allele A is 0.4. What is the frequency of gene 'a'?

Options

A. 0.6
B. 0.48
C. 0.16
D. 0.36

Answer

To solve the problem of finding the frequency of allele 'a' in a Hardy-Weinberg population where the frequency of allele 'A' is given as 0.4, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Hardy-Weinberg Principle**: The Hardy-Weinberg principle states that in a population that is not evolving, the allele frequencies will remain constant from generation to generation. The frequencies of the alleles can be represented as:
- p = frequency of allele A
- q = frequency of allele a

According to the principle, the sum of the frequencies of the two alleles must equal 1:
\[ p + q = 1 \]

2. **Identify the given information**: From the question, we know that:
- Frequency of allele A (p) = 0.4

3. **Calculate the frequency of allele 'a' (q)**: Using the equation from the Hardy-Weinberg principle, we can rearrange it to find q:
\[ q = 1 - p \]
Substituting the value of p:
\[ q = 1 - 0.4 \]
\[ q = 0.6 \]

4. **Conclusion**: The frequency of allele 'a' is 0.6.

### Final Answer:
The frequency of gene 'a' is **0.6**.

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