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

Options

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

Answer

To solve the question regarding the presence of Barr bodies in the karyotypes 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 found in females. The formula to determine the number of Barr bodies is given by the formula:
\[ \text{Number of Barr Bodies} = n - 1 \]
where \( n \) is the number of X chromosomes.

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

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

4. **Down Syndrome Female**:
- Down syndrome is caused by the presence of an extra chromosome 21 (karyotype: XX + 21).
- The sex chromosomes remain normal (two X chromosomes).
- Here, \( n = 2 \).
- Applying the formula:
\[ \text{Number of Barr Bodies} = 2 - 1 = 1 \]
- Therefore, a Down syndrome female also has **1 Barr body**.

5. **Compile the Results**:
- Turner syndrome female: 0 Barr bodies
- Normal female: 1 Barr body
- Down syndrome female: 1 Barr body

### Final Answer:
The presence of Barr bodies in the karyotypes is as follows:
- Turner syndrome female: **0**
- Normal female: **1**
- Down syndrome female: **1**

Thus, the answer is **0, 1, 1**.