Number of Barr bodies in XXXX female would be

Options

A. 1
B. 2
C. 3
D. 4

Answer

To determine the number of Barr bodies in a female with the genotype XXXX, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Barr Bodies**: Barr bodies are the inactivated X chromosomes in females. In humans, females typically have two X chromosomes (XX), and one of these X chromosomes becomes inactivated during early embryonic development. This process is known as X-inactivation or dosage compensation.

2. **Counting X Chromosomes**: In the case of a female with the genotype XXXX, we note that there are a total of four X chromosomes present.

3. **Applying the Barr Body Formula**: The number of Barr bodies is calculated using the formula:
\[ \text{Number of Barr Bodies} = \text{Total Number of X Chromosomes} - 1 \]
This formula indicates that for each additional X chromosome beyond the first, one additional Barr body will be formed.

4. **Calculating the Barr Bodies**:
- Here, we have 4 X chromosomes.
- Applying the formula:
\[ \text{Number of Barr Bodies} = 4 - 1 = 3 \]

5. **Conclusion**: Therefore, a female with the genotype XXXX would have 3 Barr bodies.

### Final Answer:
The number of Barr bodies in a XXXX female would be **3**.

---