necessary
therefore
extremely rare
determinant
polymorphic gene
able
the totol of antigenic specificities of the lymphocytes in an individual, called the lymphocye reportoire,is extremely large.
individual
The immune tem of higher vertebrate consists of two component innate and adaptive. the innate immune system.relies on a set of germline encoded receptors that recognize conserved molecular pattens found only in microorganism, the adaptive immune system uses somatically generated antigen receptor which are clonally distributed on the two type of lymphocyte t cell and b cell