Who discovered that Barr body is formed from X-chromosome

Options

A. Barr and Bertram
B. Lyon
C. Sharp and Roberts
D. Ohno and Hanaschka.

Answer

To answer the question "Who discovered that Barr body is formed from X-chromosome?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Barr Body**:
- A Barr body is an inactivated X chromosome found in female mammals. Females have two X chromosomes (XX), and one of these X chromosomes is randomly inactivated during early embryonic development, forming the Barr body.

2. **Identifying the Discovery**:
- The discovery of the Barr body and its association with the X chromosome is attributed to a scientist.

3. **Analyzing the Options**:
- The options provided are:
- A) Barr and Bertram
- B) Mary Lyon
- C) Sharp and Roberts
- D) Ohno and Hennaskela

4. **Reviewing Historical Context**:
- Mary Lyon is known for her work on X-chromosome inactivation, which is directly related to the formation of Barr bodies. She proposed the Lyon Hypothesis, which explains how one of the X chromosomes in females is inactivated.

5. **Selecting the Correct Answer**:
- Based on the information, the correct answer is **B) Mary Lyon**.

### Final Answer:
The scientist who discovered that Barr body is formed from the X-chromosome is **Mary Lyon**.

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