Which of the following immunoglobulins does constitute the largest percentage in human milk ?

Options

A. Ig D
B. Ig M
C. Ig A
D. Ig G

Answer

To determine which immunoglobulin constitutes the largest percentage in human milk, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Immunoglobulins**:
- Immunoglobulins, also known as antibodies, are proteins produced by the immune system to fight against foreign antigens such as bacteria, viruses, and other pathogens.

2. **Identify the Types of Immunoglobulins**:
- There are five main classes of immunoglobulins: IgG, IgM, IgA, IgD, and IgE. Each type has a specific role in the immune response.

3. **Focus on Human Milk**:
- The question specifically asks about the immunoglobulin present in human milk.

4. **Research the Composition of Human Milk**:
- Human milk is known to contain various immunoglobulins, but the one that is most abundant is immunoglobulin A (IgA).

5. **Determine the Percentage of IgA in Human Milk**:
- IgA constitutes about 10-15% of the total immunoglobulin content in human plasma and is significantly present in human milk, particularly in the first milk known as colostrum.

6. **Conclusion**:
- Based on the information gathered, the immunoglobulin that constitutes the largest percentage in human milk is **IgA**.

### Final Answer:
The immunoglobulin that constitutes the largest percentage in human milk is **IgA**.

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