The locus of mutation is :-

Options

A. Gene
B. Chromosome
C. Centromere
D. Nucleus

Answer

**Step-by-Step Solution:**

1. **Understanding Mutation**: A mutation is defined as a sudden change in the genetic sequence or coding sequence of an organism. This change can occur in various forms, such as substitutions, deletions, or insertions of nucleotides.

2. **Location of Mutation**: The question asks about the locus of mutation, which refers to the specific location where the mutation occurs. Mutations can happen anywhere in the genetic material, but they are most significant when they occur in coding regions.

3. **Cellular Context**: In eukaryotic cells, the genetic material is housed within the nucleus. The nucleus contains chromatin, which is the material that makes up chromosomes.

4. **Chromosomes and Genes**: Chromosomes are structures made of DNA and proteins, and they contain genes. Each gene has a specific locus on the chromosome, which is its physical location.

5. **Coding Sequences**: The coding sequences of genes are made up of codons, which are sequences of three nucleotides that correspond to specific amino acids. Mutations that affect these coding sequences can lead to changes in the protein produced by the gene.

6. **Conclusion**: Therefore, the locus of mutation is primarily found in the genes, specifically within the coding sequences of those genes.

**Final Answer**: The locus of mutation is in the genes.

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