Another mutation occurring in an already mutated gene gives rise to

Options

A. multiple genes
B. multiple alleles
C. polygenes
D. pleiotropic genes

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the outcome of another mutation occurring in a gene that has already undergone a mutation. We need to identify what this could lead to among the given options: multiple genes, multiple alleles, polygenes, or pleiotropic genes.

2. **Defining Key Terms**:
- **Multiple Genes**: Refers to a family of genes that are related and may have similar functions or sequences.
- **Multiple Alleles**: Variants of a gene that exist at a single locus.
- **Polygenes**: Refers to traits controlled by multiple genes, often leading to continuous variation.
- **Pleiotropic Genes**: Genes that affect multiple traits.

3. **Analyzing the Effects of Mutation**:
- When a gene undergoes a mutation, it can lead to changes in its function or expression. If another mutation occurs in this already mutated gene, it can further alter its function or lead to the creation of new gene variants.
- The concept of a **gene family** arises when duplication of an ancestral gene occurs, followed by mutations that lead to divergence. This means that multiple mutations can lead to the formation of multiple genes from a single ancestral gene.

4. **Conclusion**: Based on the analysis, the most appropriate answer to the question is that another mutation in an already mutated gene gives rise to **multiple genes**. This is because the process of mutation and duplication can lead to a family of related genes.

5. **Final Answer**: The correct option is **multiple genes**.

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