91Ó°ÊÓ

Fill in the Blank The heavy chains of an antibody molecule contain _______ region segments, which help to determine its class or isotype.

Fill in the Blank The variable regions of the heavy and light chains form the _______ sites of an antibody.

Fill in the Blank MHC molecules are used for antigen _______ to T cells.

Fill in the Blank MHC II molecules are made up of two subunits ( \(\alpha\) and \(\beta\) ) of approximately equal size, whereas MHC I molecules consist of a larger \(\alpha\) subunit and a smaller subunit called _______.

Fill in the Blank A______ T cell will become activated by presentation of foreign antigen associated with an MHC I molecule.

Fill in the Blank A______T cell will become activated by presentation of foreign antigen in association with an MHC II molecule.

Fill in the Blank Both ______ and effector \(T\) cells are produced during differentiation of activated \(T\) cells.

Fill in the Blank ______antigens can stimulate B cells to become activated but require cytokine assistance delivered by helper T cells.

Fill in the Blank T-independent antigens can stimulate \(\mathrm{B}\) cells to become activated and secrete antibodies without assistance from helper T cells. These antigens possess _______ antigenic epitopes that cross-link BCRs.

Fill in the Blank A(n)______ pathogen is in a weakened state; it is still capable of stimulating an immune response but does not cause a disease.