In a random mating population frequency of dominent allele is `0.7.` What will be the frequency of homozygous dominant phenotype.

Options

A. `0.49`
B. `0.09`
C. `0.3`
D. `0.21`

Answer

To solve the problem of finding the frequency of the homozygous dominant phenotype in a random mating population where the frequency of the dominant allele (P) is 0.7, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Frequency of the Dominant Allele (P)**:
- Given that the frequency of the dominant allele (P) is 0.7.

2. **Calculate the Frequency of the Recessive Allele (q)**:
- The frequency of the recessive allele (q) can be calculated using the formula:
\[ q = 1 - p \]
- Substituting the value of p:
\[ q = 1 - 0.7 = 0.3 \]

3. **Use the Hardy-Weinberg Principle**:
- According to the Hardy-Weinberg principle, the frequencies of the genotypes can be represented as:
\[ p^2 + 2pq + q^2 = 1 \]
- Here, \(p^2\) represents the frequency of the homozygous dominant phenotype.

4. **Calculate the Frequency of Homozygous Dominant Phenotype (p²)**:
- To find the frequency of the homozygous dominant phenotype, we calculate \(p^2\):
\[ p^2 = (0.7)^2 = 0.49 \]

5. **Conclusion**:
- Therefore, the frequency of the homozygous dominant phenotype is 0.49.

### Final Answer:
The frequency of the homozygous dominant phenotype is **0.49**.

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