Humoral immunity is due to

Options

A. T-lymphocytes
B. L-lymphocytes
C. P-lymphocytes
D. B-lymphocytes/Plasma cells

Answer

**Step-by-Step Solution:**

1. **Understanding Humoral Immunity**: Humoral immunity is a type of immune response that is mediated by antibodies in the blood. It primarily involves B lymphocytes (B cells) and the antibodies they produce.

2. **Identifying the Role of B Lymphocytes**: B lymphocytes are a type of white blood cell that plays a crucial role in the humoral immune response. When B cells encounter an antigen (a harmful pathogen), they can differentiate into plasma cells.

3. **Function of Plasma Cells**: Plasma cells are specialized B cells that produce and secrete large quantities of antibodies. These antibodies bind to specific antigens on pathogens, marking them for destruction and neutralizing their harmful effects.

4. **Differentiating Between Types of Lymphocytes**:
- T lymphocytes (T cells) are involved in cell-mediated immunity, not humoral immunity.
- The options provided in the question include T lymphocytes, L lymphocytes, and P lymphocytes, which are not relevant to humoral immunity.
- The correct answer involves B lymphocytes and plasma cells, as they are responsible for producing antibodies.

5. **Conclusion**: Therefore, the correct answer to the question "Humoral immunity is due to" is option 4: B lymphocyte and plasma cell.

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