The type of immunoglobulin present in the colostrum secre- ted by mammary glands is:

Options

A. IgD
B. IgE
C. IgG
D. IgA

Answer

**Step-by-Step Solution:**

1. **Understanding Immunoglobulins**: Immunoglobulins, abbreviated as Ig, are proteins that function as antibodies in the immune system. They play a crucial role in identifying and neutralizing pathogens like bacteria and viruses.

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

3. **Defining Colostrum**: Colostrum is the first milk produced by mammals after giving birth. It is thick, yellowish in color, and is rich in antibodies, providing essential immunity to the newborn.

4. **Identifying the Predominant Immunoglobulin in Colostrum**: Among the various immunoglobulins present in colostrum, IgA is the most predominant type. It is crucial for mucosal immunity and is particularly important for infants as it helps protect them from infections.

5. **Conclusion**: Therefore, the type of immunoglobulin present in the colostrum secreted by mammary glands is IgA.

**Final Answer**: IgA

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