Q. The first antibody which gets formed in response to an antigen is

 1156  214 AMUAMU 1999 Report Error

Solution:

: is the largest of the immunoglobulins and the first to reach the site of infection being present in the circulating fluid. When a B- lymphocyte is first stimulated by antigen is the first antibody type to be produced during an immune response. fixes complement and does not cross placenta. Later on replaces . is the main antibody in the secondary response. It crosses the placenta. is the predominant antibody class in seromucous secretions such as saliva, tears, colostrums and respiratory, gastrointestinal and urinogenital secretions. provides the first line of defence against invading pathogens, inhibiting their adherence to the mucosal cells and to preventing their invasions of the body.