Addition of individual chromosomes is mutation called

Options

A. Polyploidy
B. Structural mutation
C. Polysomy
D. Point mutation.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about a specific type of mutation characterized by the addition of individual chromosomes.

2. **Identifying the Options**: The options provided are:
- Polyploidy
- Structural mutation
- Polysomy
- Point mutation

3. **Defining Each Term**:
- **Polyploidy**: This refers to a condition where there are one or more extra sets of chromosomes (e.g., 3n, 4n).
- **Structural Mutation**: This involves changes in the structure of chromosomes, such as deletions, duplications, or inversions.
- **Polysomy**: This is the condition where there is one or more extra individual chromosomes (e.g., 2n + 1, 2n + 2).
- **Point Mutation**: This is a mutation that affects a single nucleotide in the DNA sequence.

4. **Analyzing the Options**:
- Polyploidy does not fit the description since it involves entire sets of chromosomes, not individual ones.
- Structural mutation does not apply here as it pertains to structural changes rather than the number of chromosomes.
- Point mutation is also not relevant as it deals with changes at the nucleotide level.

5. **Conclusion**: The correct answer is **Polysomy**, as it specifically refers to the addition of individual chromosomes beyond the normal count.

**Final Answer**: Polysomy

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