Barr body present in karyotype of Turner syndrome female, normal female,Down syndrome female. Respectively?

Options

A. 0,1
B. 0,1,2
C. 1,0,1
D. 1,1,0

Answer

To solve the question regarding the number of Barr bodies present in the karyotype of Turner syndrome females, normal females, and Down syndrome females, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Barr Bodies**: Barr bodies are inactivated X chromosomes in females. The formula to calculate the number of Barr bodies is given by \( n - 1 \), where \( n \) is the number of X chromosomes.

2. **Turner Syndrome (Karyotype: X0)**:
- Turner syndrome is characterized by the presence of only one X chromosome (karyotype: X0).
- Here, \( n = 1 \) (only one X chromosome).
- Applying the formula:
\[ \text{Number of Barr bodies} = n - 1 = 1 - 1 = 0 \]
- Therefore, there are **0 Barr bodies** in Turner syndrome.

3. **Normal Female (Karyotype: XX)**:
- A normal female has two X chromosomes (karyotype: XX).
- Here, \( n = 2 \).
- Applying the formula:
\[ \text{Number of Barr bodies} = n - 1 = 2 - 1 = 1 \]
- Therefore, there is **1 Barr body** in a normal female.

4. **Down Syndrome Female (Karyotype: XX)**:
- Down syndrome in females typically involves an extra chromosome 21, but they still have two X chromosomes (karyotype: XX).
- Here, \( n = 2 \).
- Applying the formula:
\[ \text{Number of Barr bodies} = n - 1 = 2 - 1 = 1 \]
- Therefore, there is **1 Barr body** in a Down syndrome female.

5. **Final Summary**:
- Turner syndrome female: 0 Barr bodies
- Normal female: 1 Barr body
- Down syndrome female: 1 Barr body

### Conclusion:
The number of Barr bodies present in the karyotype of Turner syndrome female, normal female, and Down syndrome female is **0, 1, and 1**, respectively.