IMMUNOLOGY

Detailed explanation-1: -IgM is the first antibody secreted by the adaptive immune system in response to a foreign antigen. Monomeric IgM is a heterotetramer of approximately 180 kDa.

Detailed explanation-2: -IgM is the largest antibody, and it is the first antibody to appear in the response to initial exposure to an antigen.

Detailed explanation-3: -IgM is the largest antibody and the first one to be synthesized in response to an antigen or microbe, accounting for 5% of all immunoglobulins present in the blood. IgM typically exists as polymers of identical subunits, with a pentameric form as the prevalent one.

Detailed explanation-4: -IgM is the largest antibody, with five Y structures being joined by their Fc regions in a circular configuration. IgM is expressed on the surface of B cells and present in serum, making up about 10 % of antibodies in the blood.

Detailed explanation-5: -IgM is the largest antibody as it is a pentamer which has 10 antigen binding sites, therefore it is more efficient and gives strong immune response. It is the first antibody to reach the site of infection. They are found majorly in blood and lymph, where most of the antigens are present.

Detailed explanation-6: -IgM is the first antibody produced in primary immune response. IgM has five antigen binding sites and hence, IgM can bind more antigen molecules. Hence, it can swiftly neutralise more antigens initially. IgG is also secreted but in much lesser amounts and also later than IgM.

Detailed explanation-7: -The first antibodies to be produced in a humoral immune response are always IgM, because IgM can be expressed without isotype switching (see Figs 4.20 and 9.8). These early IgM antibodies are produced before B cells have undergone somatic hypermutation and therefore tend to be of low affinity.