Turner syndrome is an example of

Options

A. Structural chromosomal aberration - Due to non - disjunction
B. Numerical chromosomal aberration - Due to disjunction
C. Aneuploidy - Due to non - disjunction
D. Both (B) and (C)

Answer

To solve the question regarding Turner syndrome, we need to analyze the options provided and understand the nature of Turner syndrome itself.

### Step-by-Step Solution:

1. **Understanding Turner Syndrome**:
- Turner syndrome is a chromosomal disorder that occurs in females. It is characterized by the absence of one of the X chromosomes, leading to a 45, XO genotype.

2. **Identifying the Type of Chromosomal Aberration**:
- Chromosomal aberrations can be classified into two main categories: structural and numerical.
- Structural aberrations involve changes in the structure of chromosomes (like deletions, duplications, inversions, or translocations), while numerical aberrations involve changes in the number of chromosomes.

3. **Analyzing the Options**:
- **Option A**: Structural chromosomal aberration due to non-disjunction.
- Turner syndrome is not a structural aberration; it is due to the absence of a chromosome, so this option is incorrect.
- **Option B**: Numerical chromosomal aberration due to non-disjunction.
- Turner syndrome results from the loss of one X chromosome, which is a numerical change. This option is potentially correct.
- **Option C**: Aneuploidy due to non-disjunction.
- Aneuploidy refers to the presence of an abnormal number of chromosomes in a cell. Since Turner syndrome involves having one less chromosome (45 instead of 46), it is indeed a type of aneuploidy. This option is also correct.
- **Option D**: Both B and C.
- Since both options B and C are correct, this option is also correct.

4. **Conclusion**:
- The correct answer to the question "Turner syndrome is an example of" is **Option D: both B and C**.

### Final Answer:
Turner syndrome is an example of both numerical chromosomal aberration due to non-disjunction and aneuploidy due to non-disjunction.

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