There are two critically important aspects of adaptive immunity. The first is specificity, while the second is ________.

________ immunity involves the production of antibody molecules that bind to specific antigens.

The heavy chains of an antibody molecule contain ________ region segments, which help to determine its class or isotype.

The variable regions of the heavy and light chains form the ________ sites of an antibody.

MHC molecules are used for antigen ________ to T cells.

MHC II molecules are made up of two subunits (α and β) of approximately equal size, whereas MHC I molecules consist of a larger α subunit and a smaller subunit called ________.

A ________ T cell will become activated by presentation of foreign antigen associated with an MHC I molecule.

A ________ T cell will become activated by presentation of foreign antigen in association with an MHC II molecule.

A TCR is a protein dimer embedded in the plasma membrane of a T cell. The ________ region of each of the two protein chains is what gives it the capability to bind to a presented antigen.

Peripheral tolerance mechanisms function on T cells after they mature and exit the ________.

Both ________ and effector T cells are produced during differentiation of activated T cells.

________ antigens can stimulate B cells to become activated but require cytokine assistance delivered by helper T cells.

T-independent antigens can stimulate B cells to become activated and secrete antibodies without assistance from helper T cells. These antigens possess ________ antigenic epitopes that cross-link BCRs.

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

________ immunity occurs when antibodies from one individual are harvested and given to another to protect against disease or treat active disease.

In the practice of ________, scabs from smallpox victims were used to immunize susceptible individuals against smallpox.