Question

The type of immunoglobulin, whose function is possible antigen recognition by B cells, may be
A. IgE
B. IgA
C. IgD
D. IgG

Answer 1

-Immunoglobulin (antibody) is a very important part of our immune system which plays an important role to fight with foreign antigen (unwelcome pathogen). They attach to the foreign substances, such as bacteria, viruses and destroy them.

Complete answer:
To answer this question you must know the function of all classes of immunoglobulin.
Immunoglobulin are proteins produced by plasma cells and lymphocytes are very essential for our immune system. It fights with the foreign antigen which can cause the disease so it bind with those foreign with those foreign antigen to destroy them.
There are several classes of immunoglobulin and have different function such as
Immunoglobulin A (IgA) :- it prevents the attachment of bacteria and viruses to mucus membranes.
Immunoglobulin G (IgG):- it recognizes the bacteria and opsonizes the bacteria, making them easier to phagocytose and it has fixed complement so that it enhances bacterial killing and neutralizes the toxins released by bacteria.
Immunoglobulin E (IgE):- it mediated hypersensitivity (allergy) by causing release of mediators from mast cells and basophils depending upon antigen.
IhD stands for ischemic heart disease also known as CAD coronary artery disease caused by inadequate supply of blood and oxygen to the myocardium.

Thus IgG immunoglobulin help to recognizing the antigen therefore correct option of the given question is (D) IgG

Note:-
There are five main classes of immunoglobulin – IgA, IgM, IgD, IgE and IgG. All classes have different functions and properties determined by structural variation. IgA is the main class of immunoglobulin found in tears, saliva, respiratory, intestinal secretion and colostrums. IgG is the most common class of immunoglobulin present in large amounts in blood and tissue fluids.