Antibodies are formed by

Options

A. Plasma cells
B. Histiocytes
C. Mast cells
D. None of the above.

Answer

**Step-by-Step Text Solution:**

1. **Understanding Antibodies**: Antibodies are specialized proteins that play a crucial role in the immune response by identifying and neutralizing foreign objects like bacteria and viruses.

2. **Source of Antibodies**: Antibodies are produced by specialized white blood cells known as B cells or B lymphocytes.

3. **Activation of B Cells**: B cells become activated when they encounter foreign particles or pathogens (referred to as antigens). This encounter triggers their differentiation.

4. **Differentiation of B Cells**: Upon activation, B cells differentiate into two main types of cells:
- **Plasma Cells**: These cells are responsible for the production and secretion of antibodies.
- **Memory Cells**: These cells remain in the body to provide long-term immunity by "remembering" the specific antigens for future encounters.

5. **Function of Plasma Cells**: The plasma cells secrete antibodies that are specific to the antigens. These antibodies bind to the antigens, marking them for destruction by other immune cells.

6. **Conclusion**: Therefore, the correct answer to the question "Antibodies are formed by" is that they are formed by plasma cells, which are derived from B cells.