Bio 103 Study Guide Rated A+

Which of these molecules is incorrectly paired with a source? A.)interferons - virus-infected cells B.)chemokines - cytotoxic T cells C.)antibodies - B cells D.)lysozyme - tears E.)cytokines - helper T cells {Ans: B.)chemokines - cytotoxic T cells}Which of the following is not true about helper T cells? A.)They function in cell-mediated and humoral responses. B.)They recognize polysaccharide fragments presented by class II MHC molecules. C.)They bear surface CD4 molecules. D.)They are subject to infection by HIV. E.)When activated, they secrete cytokines. {Ans: B.)They recognize polysaccharide fragments presented by class II MHC molecules.}Which protein presents viral antigens on the outer surface of cells? A.)T cell receptor. B.)MHC protein. C.)B cell receptor. D.)Antibody. {Ans: B.)MHC protein.}Which of the following events of the innate immune response occurs first when a wound that breaks the skin has occurred? A.)Neutrophils secrete substances that degrade bacterial cell walls. B.)Macrophages present bacterial proteins as antigens on their plasma membrane. C.)Platelets release proteins that form clots and decrease bleeding. D.)Mast cells secrete chemical messengers to regulate blood flow to the wound. {Ans: C.)Platelets release proteins that form clots and decrease bleeding.}How are cytotoxic T lymphocytes (CTLs) produced? A.)CD8+ T cells divide and differentiate into