Klinefelter's syndrome is characterised by a karyotype of

Options

A. XYY
B. XO
C. XXX
D. XXY

Explanation

**Step-by-Step Solution:**

1. **Understanding Klinefelter's Syndrome**: Klinefelter's syndrome is a genetic condition that occurs in males who have an extra X chromosome. This condition is characterized by a specific karyotype.

2. **Identifying the Karyotype**: The karyotype of Klinefelter's syndrome is typically represented as 47,XXY. This means that there are 47 chromosomes in total, with two X chromosomes and one Y chromosome.

3. **Analyzing the Options**: The question provides four options: XYY, XO, XXX, and XXY. We need to determine which of these corresponds to Klinefelter's syndrome.

4. **Evaluating Each Option**:
- **XYY**: This karyotype is associated with XYY syndrome, not Klinefelter's.
- **XO**: This karyotype is associated with Turner syndrome, which affects females.
- **XXX**: This karyotype is associated with Triple X syndrome, which also affects females.
- **XXY**: This is the karyotype for Klinefelter's syndrome.

5. **Conclusion**: Based on the analysis, the correct answer is **XXY**, which corresponds to Klinefelter's syndrome.

**Final Answer**: The karyotype characteristic of Klinefelter's syndrome is **XXY**.

---