Analyse the diagram given below and answer the questions based on it.

Give the functions of IgA, IgM, IgE and IgG.

Explanation

The functions are as follows:
(a) IgA: The Immunoglobulin A is a neutralising antibody that acts as the first line of defence against mucosal pathogens. It gets attached to the epithelial surfaces and prevents the invasion of pathogens. It comprises about 10 to 15% of the total antibodies present in the body. (b) IgM: It functions in production of B-cells. It is the first antibody to appear in response to the exposure of an antigen. It appears in the early course of infection and can reappear from time to time as per the growth of infection. It is also responsible for reactions of blood transfusion in ABO blood system. (c) IgE: This specific antibody is found in lungs, skin and mucous membrane that travels to the cell and releases the chemicals causing allergic reactions. (d) IgG: This immunoglobulin is responsible for deciding the Rh-factor of the blood. They function in protecting the body from viral and bacterial infections. It comprises about 70 to 80% of the total antibodies present in the body.