Mutation is more common when it is present in

Options

A. (a) Recessive condition
B. (b) Dominant condition
C. (c) Constant in population
D. (d) None of these

Explanation

**Step-by-Step Solution:**

1. **Understanding Mutation**: Mutation refers to a change in the DNA sequence that alters the genotype of an organism. This change can also affect the phenotype, which is the observable characteristics of the organism.

2. **Genotype and Phenotype**: The genotype is the genetic makeup of an organism, while the phenotype is the physical expression of that genotype. By observing the phenotype, we can determine whether a mutation has occurred.

3. **Mendel's Law of Dominance**: According to Gregor Mendel's law of dominance, there are two types of phenotypes: dominant and recessive. An organism can exhibit three types of genotypes:
- **Homozygous Dominant**: Both alleles are dominant (e.g., AA).
- **Heterozygous**: One dominant allele and one recessive allele (e.g., Aa).
- **Homozygous Recessive**: Both alleles are recessive (e.g., aa).

4. **Effect of Alleles on Phenotype**:
- In the homozygous dominant condition (AA), the dominant phenotype is expressed.
- In the heterozygous condition (Aa), the dominant phenotype is also expressed due to the presence of the dominant allele.
- In the homozygous recessive condition (aa), the recessive phenotype is expressed only when there are no dominant alleles present.

5. **Conclusion on Mutation**: Since mutations can lead to changes in alleles, they are more likely to be expressed in the dominant conditions (either homozygous dominant or heterozygous). Therefore, mutations are more common when they are present in a dominant condition.

6. **Final Answer**: The correct answer is that mutations are more common when they are present in a dominant condition (option B).

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