1. Extravasation of immune cells depends on Choose one: A. increased permeability of endothelial cell junctions. B. antibody production by B cells. C. down regulation of selectin proteins on endothelial cells. D. increased vasoconstriction.

2.Interferons are cytokines produced by host cells in response to intracellular infection. There are two types of interferons, type I and type II. Which of the following is a difference between these two types? Choose one: A. Type I is part of innate, nonspecific immunity, while type II is part of adaptive, specific immunity. B. Type I binds to extracellular pathogens, while type II binds to intracellular pathogens. C. Type I includes interferon-alpha and interferon-beta, while type II includes interferon-omega. D. Type I interferes with viral replication, while type II activates white blood cells.

3.Which of the following host cell products prevents viral infections by inhibiting viral replication? Choose one: A. NOD-like receptors B. type I interferons C. type II interferons D. Toll-like receptors

4. Which of the following activates a natural killer (NK) cell to kill a host cell? Choose one or more: A. presence of antibodies on the host cell B. absence of antibodies on the NK cell C. presence of antibodies on the NK cell D. absence of MHC I on the host cell E. absence of antibodies on the host cell F. absence of MHC I on the NK cell G. presence of MHC I on the host cell H. presence of MHC I on the NK cell

5.Some cells of the innate immune system present antigens to T cells of the adaptive immune system. Cells that can present the antigens are logically called antigen-presenting cells (APCs) and include which of the following? Choose one or more: A. dendritic cells B. basophils C. eosinophils D. natural killer cells E. neutrophils F. macrophages