Presence of one Barr body in WBC indicates that the person is

Options

A. Colour blind
B. Normal female
C. Haemophilic
D. normal male

Answer

To solve the question regarding the presence of one Barr body in white blood cells (WBC), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Barr Bodies**:
- Barr bodies are inactivated X chromosomes found in females. In humans, females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).

2. **X Chromosome Inactivation**:
- In females, one of the X chromosomes is randomly inactivated during early embryonic development. This inactivated X chromosome condenses to form a Barr body.

3. **Counting Barr Bodies**:
- The number of Barr bodies is always one less than the total number of X chromosomes present. Therefore, a normal female (XX) will have one Barr body (2 X chromosomes - 1 = 1 Barr body).

4. **Analyzing the Options**:
- **Colorblind**: This is an X-linked recessive disorder. A colorblind female would have two active X chromosomes (both affected), resulting in no Barr body.
- **Normal Female**: A normal female with two X chromosomes will have one Barr body.
- **Hemophilic**: Similar to colorblindness, hemophilia is also an X-linked recessive disorder. A hemophilic female would also have two active X chromosomes, resulting in no Barr body.
- **Normal Male**: A normal male has one X chromosome and one Y chromosome, resulting in no Barr body.

5. **Conclusion**:
- Since the presence of one Barr body indicates that the individual has two X chromosomes (one of which is inactivated), the correct answer is that the person is a **normal female**.

### Final Answer:
The presence of one Barr body in WBC indicates that the person is a **normal female**.

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