Find out the mismatch

Options

A. Klinefelter's syndrome -XO
B. Haemophilia -sex linked
C. Down's syndrome autosomal aneuploidy
D. Turner 's syndrome females with retarded sexual development.

Answer

**Step-by-Step Solution:**

1. **Understand the Question**: The question asks to identify the mismatch among the given options related to genetic disorders and their chromosomal complements.

2. **Analyze Klinefelter's Syndrome**: Klinefelter's syndrome is characterized by the presence of an extra X chromosome in males. The typical chromosomal complement is XXY. This occurs due to nondisjunction during meiosis, leading to a male with an additional X chromosome.

3. **Check the Given Option**: The option states Klinefelter's syndrome as X0. This is incorrect because X0 (or Turner syndrome) indicates the absence of one X chromosome, which is not the case for Klinefelter's syndrome.

4. **Identify Turner Syndrome**: Turner syndrome is characterized by a chromosomal complement of X0, meaning there is only one X chromosome and no second sex chromosome. This is a condition that affects females and is characterized by underdeveloped sexual characteristics.

5. **Evaluate Other Options**:
- Hemophilia is correctly described as a sex-linked recessive disorder located on the X chromosome.
- Down syndrome is correctly identified as an autosomal aneuploidy, specifically 2n + 1, due to an extra copy of chromosome 21.
- Turner syndrome is correctly described with a chromosomal complement of 45 chromosomes, with one missing sex chromosome (X0).

6. **Conclude the Mismatch**: Since Klinefelter's syndrome is incorrectly matched with X0, the mismatch is identified. The correct answer is that Klinefelter's syndrome should be XXY, not X0.

7. **Final Answer**: The mismatch is Klinefelter's syndrome being described as X0.

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