In mongolism/Down 's syndrome the patient has

Options

A. Barr body
B. Trisomy
C. Monsomy
D. Nullisomy

Answer

### Step-by-Step Solution:

1. **Understanding Down Syndrome**:
- Down Syndrome, also known as Mongolism, is a genetic disorder caused by the presence of an extra chromosome. This condition is characterized by a range of physical and intellectual disabilities.

2. **Identifying the Chromosomal Abnormality**:
- The specific chromosomal abnormality associated with Down Syndrome is known as trisomy. This means that instead of the normal two copies of chromosome 21, individuals with Down Syndrome have three copies (47 chromosomes in total).

3. **Evaluating the Options**:
- The question provides four options:
- A) Bar body
- B) Trisomy
- C) Monosomy
- D) Nullisomy
- We need to determine which of these options correctly describes the chromosomal condition in Down Syndrome.

4. **Analyzing Each Option**:
- **A) Bar body**: This is not relevant to Down Syndrome as it pertains to the inactivation of one X chromosome in females and is not a characteristic of Down Syndrome.
- **B) Trisomy**: This is the correct answer since Down Syndrome is specifically caused by the presence of an extra chromosome (trisomy 21).
- **C) Monosomy**: This refers to having only one copy of a chromosome instead of the normal two, which does not apply to Down Syndrome.
- **D) Nullisomy**: This refers to the absence of both copies of a chromosome, which is also not applicable to Down Syndrome.

5. **Conclusion**:
- Based on the analysis, the correct answer is **B) Trisomy**.

### Final Answer:
In Down Syndrome, the patient has **Trisomy** (specifically trisomy 21).

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