Chapter 16 study questions

A microbe is ingested and broken into fragments by an antigen-presenting cell (APC). Which of the following would you expect to occur? A. B cells will bind to antigens on the surface of the APC. B. B cells will release cytokines to activate T cells. C. Plasma cells will release cytokines to activate the APC. D. T cells will bind to antigens on the surface of the APC

D. T cells will bind to antigens on the surface of the APC

Which of the following scenarios is an example of an allotypic difference? a. A single amino acid change gives rise to a new form of IgG antibody in humans. b. Humans and dogs have slightly different immunoglobulins. c. A human is able to generate antigen specificity by rearranging genes. d. There are five major classes of immunoglobulins within an individual

a. A single amino acid change gives rise to a new form of IgG antibody in humans.

Which of the following statements is an example of a situation in which cross-protection will occur? a. A vaccine is administered for one of two viruses that share epitopes. b. A single virus triggers a response from both B cells and T cells. c. An antigen forms a cross-link between two antibodies. d. A combination vaccine is administered to provide protection against three viruses.

a. A vaccine is administered for one of two viruses that share epitopes

Class switching is the process in which.. a. B cells switch from producing IgM of IgD to producing IgE, IgG, or IgA. b. formed IgM antibody pentamers break apart into IgM monomers. c. antibody released from the surface of a B cell switches to a different heavy chain. d. higher-affinity antibodies are produced upon repeated exposure to the same antigen

a. B cells switch from producing IgM of IgD to producing IgE, IgG, or IgA.

Why does B-cell proliferation and differentiation often require assistance from helper T cells? a. Capping does not occur unless epitopes are found in multiple copies. b. B cells require antigen presentation by helper T cells. c. Microbes often destroy B-cell receptors and then B cells require help from T cells. d. Helper T cells are required to move epitopes closer together for capping by B cells

a. Capping does not occur unless epitopes are found in multiple copies.

The molecule indicated on this illustration of the first signal during the activation of a cytotoxic T cell (TC) must be... a. Class I MHC. b. Class II MHC c. a CD8 molecule. d. a B7 protein.

a. Class I MHC.

A newborn receives passive immunity through.. a. IgG. b. IgM. c. IgD. d. IgE

a. IgG

Antigen bound by the molecule shown would be recognized by ____ cells. a. Tc b. TH2 c. TH17 d. B

a. Tc

T cells capable of killing virus-infected and cancer cells are known as _____ cells. a. Tc b. TH2 c. TH17 d. TH1

a. Tc

The process illustrated in this figure is best described as.. a. capping. b. T-cell-dependent activation. c. class switching. d. clonal selection

a. capping

Which of the following cell types is considered a "nonprofessional" antigen-presenting cell? a. fibroblast b. macrophage c. dendritic cell d. B cell

a. fibroblast

Which of the following accurately describes how a foreign molecule leads to the production of antibody? a. Individual epitopes on an antigen are recognized and a single antibody is produced for each epitope. b. The immune system recognizes whole microbes and responds by secreting a single antibody against the microbe. c. The immune system recognizes individual haptens on an antigen and secretes several antibodies directed against that hapten. d. Groups of epitopes on an antigen are recognized and a single antibody is produced for each group.

a. individual epitopes on an antigen are recognized and a single antibody is produced for each epiitope

The direct consequence of a CD40 protein on a B cell binding to a CD40 ligand on a T cell is.... a. initiation of an intracellular signal required for B cell activation. b. heavy-chain class switching in the B cell. c. release of IL-2 from the T cell. d. release of perforins and granzymes from the T cell.

a. initiation of an intracellular signal required for B cell activation

T-cell receptors (TCRs) are only able to bind a. peptides. b. lipids. c. polysaccharides. d. DNA

a. peptides

The figure shown illustrates clonal expansion of activated B cells. What are the two cell types produced by this cell line? a. plasma cells and memory B cells b. antigen-presenting cells and memory T cells c. activated T cells and plasma cells d. memory B cells and dendritic cells

a. plasma cells and memory B cells

One health risk associated with excessive cytokine release is the chance of.. a. severe tissue damage. b. cytokines destroying antibodies. c. damage to virally infected cells. d. inactivating mitosis.

a. severe tissue damage.

Individuals with bare lymphocyte syndrome lack MHC II proteins. Which of the following could still occur in an individual lacking MHC II proteins? a. Helper T cells could use T-cell receptors to interact with macrophages. b. B cells could produce IgM antibodies. c. Cytotoxic T cells could become activated. d. B cells could undergo class switching independently

b. B cells could produce IgM antibodies.

When comparing the primary and secondary immune responses, which of the following is true? a. IgM titer levels are much higher during a secondary immune response. b. IgG titer levels are much higher during a secondary immune response. c. IgM titer levels are higher than IgG titer levels during the primary immune response. d. IgM titer levels are higher than IgG titer levels during the secondary immune response.

b. IgG titer levels are much higher during a secondary immune response.

Which of the following statements accurately describes how memory B cells become activated during the secondary immune response? a. Memory B cells present antigen bound to MHC II and bind to TH cells. b. Memory B cells respond to soluble IL-4 and IL-6 without direct contact with TH cells. c. Memory B cells must bind IgM antibody on activated B cells. d. Memory B cells use CD40 surface proteins to attach to CD40 ligands on TH cells.

b. Memory B cells respond to soluble IL-4 and IL-6 without direct contact with TH cells

T cells that secrete IL-4, IL-5, and IL-6 and that play a major role in helping B cells are known as __________cells. a. Treg b. TH2 c. TH1 d. TH0

b. TH2

How would you expect an injection of killed or attenuated Salmonella typhi, the causative agent of typhoid fever, to protect an individual? a. The injection would cause the individual to have a mild case of typhoid fever, but would protect against future cases of typhoid fever. b. The injection would provide antigens recognizable by the immune system and memory cells would form to prevent typhoid fever in the future. c. The injection would provide cross-protection to prevent several diseases caused by different bacteria. d. The injection would provide the individual with premade antibodies capable of binding to and inactivating Salmonella typhi.

b. The injection would provide antigens recognizable by the immune system and memory cells would form to prevent typhoid fever in the future.

Which of the following would you expect to elicit the largest production of antibodies? a. haptens floating freely within plasma b. a complex protein with many different epitopes c. a polysaccharide with several identical segments d. a small lipid

b. a complex protein with many different epitopes

The figure shown illustrates a bacterial cell that a. acts as an antigen. b. is broken down into many antigens. c. is producing antibodies in response to antigens. d. has a single epitope.

b. broken down into many antigens

The immunoglobulin superfamily of proteins includes... a. immunoglobulins only. b. immunoglobulins, major histocompatibility complex, and B- and T-cell receptors. c. major histocompatibility complex and B- and T-cell receptors only. d. IgA, IgG, IgM, IgE, and IgD only.

b. immunoglobulins, major histocompatibility complex, and B- and T-cell receptors.

Almost 95% of T cells entering the thymus die when apoptosis is triggered during..... a. positive selection. b. negative selection. c. antibody production. d. MHC recognition

b. negative selection

The second signal required for TC activation is... a. binding of a CD28 molecule on the T cell to a B7 protein on an antigen-presenting cell. b. secretion of the cytokine IL-2 from a TH1 cell. c. binding of a CD8 molecule on the T cell to an antigen-MHC I complex on an antigen- presenting cell. d. secretion of the cytokine IL-1 from a TH0 cell

b. secretion of the cytokine IL-2 from a TH1 cell.

Which of the following statements correctly describes the molecules that elicit an immune response? a. Antigens are small molecules that must be bound to an immunogen to elicit an immune response. b. Small segments of an antigen that elicit an immune response are called epitopes. c. Haptens are proteins that elicit the synthesis of antibodies and are also known as antigens. d. Immunogens are small segments of antigens that are recognized by the immune system.

b. small segments of an antigen that elicit an immune response are called epitopes

Why are cytotoxic T (TC) cells more effective than antibodies at clearing viral infections? a. TC cells are able to recognize free viral particles as they circulate through lymph nodes. b. Antibodies bind weakly to antigen-MHC I complexes on antigen-presenting cells. c. Antibodies are only able to bind to extracellular antigen, and viruses tend to be intracellular. d. TC cells are activated more strongly than B cells by cytokines released by helper T cells.

c. Antibodies are only able to bind to extracellular antigen, and viruses tend to be intracellular.

This figure shows the structure of an _________ antibody. a. IgG b. IgA c. IgM d. IgE

c. IgM

MHC molecules are required for.. a. B cell activation. b. phagocytosis of microbes. c. T cell activation d. proteasome degradation of viruses.

c. T cell activation

Which of the following would most directly eliminate an intracellular pathogen such as a virus? a. production of antibody b. activation of B cells c. activation of cytotoxic T cells d. activation of helper T cells

c. activation of cytotoxic T cells

The antigen-binding site on an antibody... a. is composed of light chains only. b. contains constant amino acid sequences within each class. c. contains highly variable amino acid sequences. d. is composed of heavy chains only.

c. contains highly variable amino acid sequences.

IgG, IgA, IgM, IgD, and IgE are all examples of.... a. antigens. b. idiotypes. c. isotypes. d. allotypes

c. isotypes

Clonal expansion of B cells occurs when a(n)... a. antigen-presenting cell binds to a single B cell. b. helper T cell secretes antibody onto a single B cell. c. single B cell becomes activated when its receptor binds to a single epitope. d. memory B cell attaches onto an antigen-presenting cell.

c. single B cell becomes activated when its receptor binds to a single epitope

What is the function of an antigen-presenting cell (APC)? a. An APC presents antigen to macrophages to stimulate the synthesis of antibodies. b. An APC presents antigen to B cells to stimulate the formation of memory B cells. c. An APC presents antigen to memory T cells to stimulate the synthesis of cytokines. d. An APC presents antigen to helper T cells to activate the T cells during a cellular response.

d. An APC presents antigen to helper T cells to activate the T cells during a cellular response.

The cell indicated on this illustration has the surface molecule.... a. CD4. b. Class I MHC. c. Class II MHC. d. CD8.

d. CD8

What is the function of class II MHC molecules? a. Class II MHC is used to present intracellular antigen to CD8 cells. b. Class II MHC is used to present intracellular antigen to CD4 cells. c. Class II MHC is used to present extracellular antigen to CD8 cells. d. Class II MHC is used to present extracellular antigen to CD4 cells

d. Class II MHC is used to present extracellular antigen to CD4 cells

Which two antibody classes are displayed on the surface of naïve B cells? a. IgG and IgD b. IgE and IgD c. IgE and IgM d. IgM and IgD

d. IgM and IgD

How are memory B cells able to persist for many years? a.Memory B cells are continuously stimulated by cytokines released from helper T cells. b. Memory B cells undergo hypermutation, which allows them to survive indefinitely. c. Memory B cells use gene rearrangement to prevent apoptosis from occurring. d. Memory B cells with receptors that match with antigen produce anti-apoptosis protein.

d. Memory B cells with receptors that match with antigen produce anti-apoptosis protein.

If you had a box of 200 beads that were different shapes and you randomly chose and linked together 3 beads, you would be performing a process analogous to the way.. a. T cells are able to use 200 genes to produce 3 receptor types. b. 200 B cells are able to produce 3 different antibodies. c. antigens are processed by antigen-presenting cells. d. antibody diversity is created within our bodies.

d. antibody diversity is created within our bodies.

What step would have preceded the figure shown? A. The B cell would have recognized antigen bound to an antigen-presenting cell. B. The T cell would have recognized antigen bound to an antigen-presenting cell. C. The B cell would have gone through clonal expansion. D. The T cell would have differentiated into plasma cells.

B. The T cell would have recognized antigen bound to an antigen-presenting cell.