The organ, where immature lymphocytes differentiate into antigen-sensitive lymphocytes?

Options

A. Bone marrow
B. Peyer's patches
C. Spleen
D. Lymph nodes

Answer

**Step-by-Step Solution:**

1. **Understanding Immature Lymphocytes**: Immature lymphocytes are cells that develop from hematopoietic stem cells in the bone marrow. They are not yet fully functional and need to mature to become antigen-sensitive lymphocytes.

2. **Identifying Primary Lymphoid Organs**: The primary lymphoid organs where lymphocytes mature are the thymus and the bone marrow. The thymus is responsible for the maturation of T lymphocytes, while the bone marrow is where B lymphocytes mature.

3. **Differentiation of Lymphocytes**:
- T lymphocytes mature in the thymus and are involved in cell-mediated immunity.
- B lymphocytes mature in the bone marrow and are responsible for producing antibodies in response to antigens.

4. **Function of Antigen-Sensitive Lymphocytes**: Once B lymphocytes mature, they become antigen-sensitive lymphocytes. When they encounter an antigen, they can recognize it as foreign and initiate an immune response by producing antibodies.

5. **Conclusion**: Based on the information provided, the organ where immature lymphocytes differentiate into antigen-sensitive lymphocytes is the bone marrow.

**Final Answer**: The correct answer is **bone marrow**.

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