An epitope associates with which part of an antigen receptor or antibody?a. the tailb. the heavy-chain constant regions onlyc. variable regions of a heavy chain and light chain combinedd. the light-chain constant regions only

The antigen-binding sites of an antibody molecule are formed from the molecule's variable regions. Why are these regions described as variable?

The body produces antibodies complementary to foreign antigens. The process by which the body comes up with the correct antibodies to a specific invader is most like __________.

A viral infection in a cell results in __________.

What is the primary difference between the innate and adaptive immune responses?a. The innate immune response does not distinguish between pathogens, while the adaptive immune response does.b. Only the innate immune response is activated by antigens.c. The adaptive immune response generates immunological memory and is more specific than the innate immune response.d. The innate immune response does not kill cells; the adaptive immune response does.

Which statement best describes the difference between responses of effector B cells (plasma cells) and those of cytotoxic T cells?a. B cells confer active immunity; cytotoxic T cells confer passive immunity.b. B cells respond the first time a pathogen is present; cytotoxic T cells respond subsequent times.c. B cells secrete antibodies against a pathogen; cytotoxic T cells kill pathogen-infected host cells.d. B cells carry out the cell-mediated response; cytotoxic T cells carry out the humoral response.

What is the difference between an epitope and an antigen?

Which of the following statements is true?(A) An antibody has one antigen-binding site. (B) A lymphocyte has receptors for a single antigen. (C) Every antigen has a single epitope. (D) A liver or muscle cell makes two classes of MHC molecule

Which of the following statements is not true?a. An antibody has more than one antigen-binding site.b. A lymphocyte has receptors for multiple different antigens.c. An antigen can have different epitopes.d. A liver or muscle cell makes one class of MHC molecule.