Lysis of foreign cell is mediated through

Options

A. IgM only
B. IgA only
C. IgM and IgG
D. IgD and IgE

Answer

To answer the question "Lysis of foreign cell is mediated through," we need to analyze the roles of different immunoglobulins (antibodies) in the immune response, particularly focusing on their involvement in the lysis of foreign cells.

### Step-by-Step Solution:

1. **Understanding Immunoglobulins**: Immunoglobulins, or antibodies, are proteins produced by the immune system to identify and neutralize foreign objects like bacteria and viruses. There are several classes of immunoglobulins, including IgA, IgM, IgG, IgD, and IgE.

2. **Evaluating IgA**: IgA is primarily found in mucosal areas, such as the gut, respiratory tract, and in secretions like saliva and breast milk. It plays a crucial role in mucosal immunity but is not directly involved in the lysis of foreign cells. Therefore, IgA is not the correct answer.

3. **Evaluating IgM**: IgM is the first antibody produced in response to an infection and is found in blood and lymphatic fluid. It is effective in forming complexes with antigens and activating the complement system, which leads to the lysis of foreign cells. Thus, IgM is involved in the lysis of foreign cells.

4. **Evaluating IgG**: IgG is the most abundant antibody in the blood and extracellular fluid, and it plays a significant role in the immune response. Like IgM, IgG can also activate the complement system and mediate the lysis of foreign cells. Therefore, IgG is also involved in the lysis of foreign cells.

5. **Evaluating IgD and IgE**: IgD is primarily found on the surface of immature B-lymphocytes and plays a role in the initiation of B-cell activation. IgE is involved in allergic reactions and defense against parasitic infections but is not directly involved in the lysis of foreign cells. Therefore, neither IgD nor IgE is correct in this context.

6. **Conclusion**: Since both IgM and IgG are involved in the lysis of foreign cells, the correct answer to the question is option C, which includes both IgM and IgG.

### Final Answer:
The lysis of foreign cells is mediated through **IgM and IgG** (Option C).

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