Question

Antibodies present in colostrum which protect the new born from certain diseases is of

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

Answer 1

The correct option is B

IgA type

The correct option is B.

Explanation of the correct option:

1. Antibodies are large, Y-shaped blood proteins that are produced by plasma cells. They bind to foreign particles & invade them.
2. IgA is usually found in liquids like breast milk, serum, saliva, and fluids of an intestine.
3. IgA in breast milk also protects an infant’s gastrointestinal tract from microbial activity.
4. It generally constitutes 13% of total antibody content in the serum and is divided into two sub-classes- IgA1 and IgA2.
5. Among these, IgA1 is highly found in secretions and is also called the secretory immunoglobulin.
6. It exists in both the monomeric as well as dimeric forms.
7. It provides the first line of defense against pathogens and limits inflammation.
8. It also activates the complement pathway which participates in the immune response.

Explanation of the incorrect options:

Option A:

1. Immunoglobin G is transferred to the placenta through the fetus and protects the infant until its birth.
2. It is the most abundantly found immunoglobin.

Option C:

Immunoglobin D is involved in the production of antibodies by B cells.

Option D:

Immunoglobin E is present in the linings of the respiratory and intestinal tracts and responds to allergic reactions.

Final answer: Antibodies present in colostrum that protect the newborn from certain diseases are of IgA type.