Which of the following immunoglobins (Igs) is present in milk?

Options

A. IgA
B. IgG
C. IgM
D. IgE group

Answer

To determine which immunoglobulin is present in milk, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks which immunoglobulin (Ig) is found in milk. We need to identify the specific type of immunoglobulin that is present in the milk of mothers.

2. **Identify the Types of Immunoglobulins**: There are several types of immunoglobulins, including IgA, IgG, IgM, and IgE. Each type has different functions and locations in the body.

3. **Evaluate Each Immunoglobulin**:
- **IgA**: This immunoglobulin is primarily found in mucosal areas, such as the gut, respiratory tract, and is also present in secretions like saliva, tears, and milk. It plays a crucial role in mucosal immunity.
- **IgG**: This is the most abundant immunoglobulin in the blood and is responsible for long-term immunity. It can be transferred from mother to child through the placenta but is not present in milk.
- **IgM**: This is the first antibody produced in response to an infection and is mainly found in the blood and lymphatic fluid, not in milk.
- **IgE**: This immunoglobulin is involved in allergic reactions and is not found in milk.

4. **Conclusion**: Based on the evaluation, IgA is the immunoglobulin that is specifically present in the milk of mothers. Therefore, the correct answer is IgA.

### Final Answer:
**IgA is the immunoglobulin present in milk.**

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