Question

Colostrum (mother’s milk produced immediately after childbirth) is beneficial for the immunity of the human infant because it contains
(a)IgF
(b)IgC
(c)IgB
(d)IgA

Answer 1

Hint: This immunoglobulin plays an important role in the immune functions of mucous membranes. Its abundance is roughly 10% in our body as compared to another immunoglobulin.

Complete answer:
 Colostrum is beneficial for the immunity of the human infant because it contains IgA. IgA is present in all physiological secretions. It prevents mucosal infections by agglutinating microbes.

Additional Information: (a) Bone marrow produces precursors for B and T lymphocytes. B lymphocytes produce plasma cells that produce the five immunoglobulins- IgA, IgG, IgM, IgD, and IgE.
(b) B lymphocytes comprise of the humoral immunity which is also called memory cells.
(c) Immunoglobulins are antibodies responsible for different functions in the body.
The immunoglobulin IgG can pass through the placenta and provides immunity to the growing fetus, the immunoglobulin IgM has a role in agglutination, immunoglobulin IgD functions in the development of B-lymphocytes, and immunoglobulin IgE is known for an allergic response.
IgF – It is not an immunoglobulin rather it is an insulin-like growth factor which is also called somatomedin. It is a peptide hormone that has a function to stimulate growth and is also responsible for a decrease in blood glucose levels.
IgC - There is no such immunoglobulin.
IgB- There is no such immunoglobulin.
So, the correct answer is ‘IgA’.

Note: IgG is the immunoglobulin that can pass through the placenta but IgA is present in colostrum which is beneficial for infants at the time of childbirth. IgA does not cross the placenta. IgA has the role of providing immunity by acting against microbial antigens, immunization, and allergies.