Barr body occurs in

Options

A. Interphase cell of female mammal
B. Interphase cell of male mammal
C. Prophase cell of male mammal
D. Prophase cell of female mammal

Answer

### Step-by-Step Solution:

1. **Understanding Barr Bodies**:
- A Barr body is an inactivated X chromosome found in female mammals. It is a mechanism to balance the dosage of X-linked genes between males (who have one X chromosome) and females (who have two X chromosomes).

2. **Location of Barr Bodies**:
- Barr bodies are present in the nucleus of somatic cells. They can be identified during the interphase of the cell cycle, which is the phase when the cell is not actively dividing.

3. **Identifying the Correct Option**:
- The question provides four options:
- Interphase cell of female mammal
- Interphase cell of male mammal
- Prophase cell of male mammal
- Prophase cell of female mammal

4. **Analyzing Each Option**:
- **Interphase cell of female mammal**: This is the correct option because Barr bodies are present in the interphase cells of females.
- **Interphase cell of male mammal**: Incorrect, as males have only one X chromosome and do not have Barr bodies.
- **Prophase cell of male mammal**: Incorrect for the same reason as above; males do not have Barr bodies.
- **Prophase cell of female mammal**: Incorrect because, during prophase, the cell is dividing, and the Barr body is not visible.

5. **Conclusion**:
- The Barr body occurs in the interphase cell of female mammals.

### Final Answer:
Barr body occurs in the interphase cell of female mammals.

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