Chapter 17 Homework

Mucous membranes are a part of the complement system. humoral immunity. adaptive defense. innate defense. cell-mediated immunity.

According to the animation, B cells interact directly with phagocytes. the complement system. helper T cells. inflammation.

Which of the following defense systems would be involved in eliminating virally-infected cells? Humoral immunity T lymphocytes Phagocytosis Complement system

According to the animation, antibodies interact with which innate defenses? Phagocytosis First-line defenses Phagocytosis and the complement system Phagocytosis, inflammation, and the complement system The complement system Inflammation

Which cells directly attack abnormal cells in the body? Cytotoxic T cells Helper T cells B cells Phagocytes

Phagocytosis is a process for engulfing large particles (>1μm). Which feature of antibodies will help to make particles larger, therefore enhancing phagocytosis? neutralization agglutination complement activation opsonization

The flu virus mutates fairly frequently. Its adhesive proteins change such that we have different "strains" of influenza each year. When a particular flu virus mutates such that its adhesive proteins change, which function of antibodies is disrupted? agglutination complement activation opsonization neutralization

__________________ stimulated with ___________ differentiate into __________, which secrete antibodies into the bloodstream. Antigen, plasma cells, B-cells Phagocytes, antigen, B-cells Plasma cells, antigen, B-cells B-cells, antigen, plasma cells

Antigen processing and presentation is a way for a cell to give information about its activities. is the way foreign cells engulf macrophages. is a way for viruses to infect cells. is only accomplished by bacterial cells

Why would a body cell that is not a phagocyte need to present antigens? Non-phagocytic body cells can become infected with a virus. All cells of the body can engulf invading cells. Antigens are infectious and can spread to normal cells. Antigens are required for cell-to-cell attachment

How do phagocytes communicate to other cells what they have captured? They engulf virally infected cells. They spread viruses to other cells. They present antigens from engulfed foreign cells.

Which of the following best characterizes clonal selection? The production of identical T cells producing the same antibody The production of identical B cells producing the same antibody The production of different antigens by the same B cell The production of identical B cells producing different antibodies

What is produced by the process of clonal expansion? Plasma cells Plasma cells, T cells, and memory B cells Memory B cells Plasma cells and memory B cells

An antigen that is potent enough to activate a B cell on its own is known as T-dependent antigens. T-independent antigens. antibodies. BCR.

Based on the animation, T cells recognized the antigen displayed by what protein of the B cell? BCR CD4 TCR MHC Antigen

How can a sufficient humoral immune response occur if a plasma cell only lives for a few days? Each plasma cell can proliferate into more plasma cells. Each plasma cell can produce up to 2000 antibodies every second. T cells can also produce antibodies. Memory B cells can also produce antibodies.

Which receptor on the helper T-cell recognizes the specific antigen from an antigen-presenting cell? CD4 IL-1 Receptors IL-2 Receptors TCR

TH2 cells produce cytokines that activate cytotoxic T-cells. macrophages. natural killer cells. B cells.

Which proteins on the antigen-presenting cell are recognized by the helper T-cell? IL-1 receptors MHC proteins CD8 receptors IL-2 receptors

When do helper T-cells develop into TH1 or TH2 cells? Immediately after the binding of the CD4 receptor Before autostimulation After proliferation into a clonal population After B cell activation

Natural killer cells are activated by bacterial cells. TH1 cells. antigen-presenting cells. TH2 cells.

What is apoptosis? The receptor on a cytotoxic T-cell that recognizes MHC molecules. A protein molecule that forms a pore in the membranes of infected cells. The proliferation of cytotoxic T-cells. The process of programmed cell death.

What is the function of the CD8 receptor? Bind to MHC molecules Produce gamma interferon Activate cytokines Produce IL-2

What is the fate of activated cytotoxic T-cells? They proliferate into a clone of cells specific to the same antigen; some of these cells then differentiate into long-lived memory T-cells, while others mature to attack infected cells. Each activated cytotoxic T-cell proliferates, forming a clone of cells specific to the same antigen. They can differentiate into long-lived memory T-cells. They can mature and attack infected cells. They are infected by viruses. They are destroyed via apoptosis.

Which molecule triggers apoptosis? MHC Perforin Granzyme Gamma-interferon IL-2

Which event happens first during cytotoxic T-cell activation? Clonal proliferation Secretion of granzymes and perforin CD8 binds to MHC molecules of infected cells Production of IL-2 and gamma-interferon receptor

Which of the following statements concerning cellular immunity is FALSE? Cellular immunity involves cells that recognize antigens and make specific antibodies against them. The lymphocytes involved with cellular immunity are found primarily in lymphoid organs and blood. The thymus is necessary for development of cells involved in cellular immunity. T cells respond to antigens when the antigens bind to receptors on their surface.

The primary immune response involves an immediate increase in the concentration of antibodies, followed by an immediate and sharp decline. a slow rise in the concentration of antibodies, followed by a gradual decline. a slow rise in the concentration of antibodies, followed by a rapid decline. an immediate increase in the concentration of antibodies, followed by a slow decline.

According to the animation, for approximately how many days is IgG present in the serum? Fifteen days Five days Ten days Twenty days

According to the animation, on what day does IgM first appear? Day ten Day fifteen Day five Day one

Cytokines are protein-based chemical messengers that allow for communication between cells of the immune system. True False

Which of the following is NOT a characteristic of B cells? They recognize antigens associated with MHC I. They are responsible for antibody formation. They originate in bone marrow. They are responsible for the memory response. They have antibodies on their surfaces.

Plasma cells are activated by a(n) T cell. antigen. memory cell. APC. B cell.

What makes agglutination by antibodies possible? Antibodies are produced by plasma cells. Antibodies can inactivate toxins. Antibodies can recognize bacteria as well as viruses. Each antibody has at least two antigen-binding sites

What is the role of plasma cells in humoral immunity? Plasma cells produce antibodies. Plasma cells neutralize toxins. Plasma cells activate the complement system. Plasma cells engulf viruses. Plasma cells are phagocytes.

How might a pathogenic bacterium be affected by antibodies? The antibodies may coat the surface of the bacteria (opsonization), allowing for it to be tagged for phagocytosis. The antibodies may block proteins necessary for binding the pathogen to the host, may opsonize the bacterium, or may agglutinate bacteria. The antibodies may block proteins necessary for binding the pathogen to the host. The antibodies may stick to multiple bacteria, causing agglutination.

Which of the following statements is NOT a possible outcome of antigen-antibody reaction? ADCC agglutination clonal deletion activation of complement opsonization

When an antibody binds to a toxin, the resulting action is referred to as opsonization. neutralization. agglutination. apoptosis. ADCC.

Where are MHC molecules located on a cell? In the nucleus They are not associated with any one location on the cell On the surface of the cell Inside the cell cytoplasm

What is a feature of the small fragments presented by MHC-I proteins? They are small fragments of nucleic acids, 8-10 nucleotides in length. They are large proteins from the host. They are derived from bacteria. They are small peptides, roughly 8-10 amino acids long.

Which organelle assists directly with the presentation of MHC-I antigens? The phagosome The endoplasmic reticulum The mitochondria The Golgi apparatus The nucleus

When does MHC-II loading occur? After passing through the endoplasmic reticulum During viral infection During the fusion of vesicles containing MHC-II proteins with vesicles containing digested pathogens During phagocytosis of an invading pathogen

Which of the cells listed below can present antigens on Class II MHC proteins? Virus infected epithelial cells Healthy epithelial cells Tumor cells Macrophages

Which type of cell directly attacks infected cells? Cancerous cells Cytotoxic T-cells Bacterial cells Helper T-cells

Immune cells that secrete cytokines and activate other immune cells are: Cytotoxic T-cells Helper T-cells Virally infected cells Invading pathogenic bacteria Abnormal body cells

HIV directly infects T-cells. Why is this problematic for cell-mediated immunity? HIV transforms the T-cells into cancer cells. HIV reprograms these cells to attack the body cells. Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body. HIV causes cytokines to be produced at much higher levels, altering the normal function of the immune system.

How do helper T-cells and cytotoxic T-cells work together? Helper T-cells produce cytotoxic T-cells. Cytotoxic T-cells produce cytokines to activate helper T-cells. Helper T-cells produce cytokines to activate other cells of the immune system. Cytotoxic T-cells attack abnormal body cells, while helper T-cells attack virally infected cells.

Which of the following cells is NOT an APC? mature B cells dentritic cells macrophages natural killer cells None of the answers is correct; all of these are APCs.

CD4+ T cells are activated by cytokines released by dendritic cells. cytokines released by B cells. complement. interaction between CD4+ and MHC II. interaction between TCRs and MHC II.

Which of the following recognizes antigens displayed on host cells with MHC II? natural killer cell B cell basophil TH cell TC cell

Which of the following is NOT a characteristic of cellular immunity? It can inhibit the immune response. Cells are processed in the thymus gland. The cells originate in bone marrow. T cells react with antigens. B cells make antibodies.

Which of the following destroys virus-infected cells? Treg dendritic cells B cells TH CTL

Which of the following statements about natural killer cells is FALSE? They destroy virus-infected cells. They destroy cells lacking MHC I. They are stimulated by an antigen. They destroy tumor cells. None of the answers are correct; all of these statements are true. f

A Treg cell deficiency could result in increased number of viral infections. autoimmunity. increased number of bacterial infections. increased severity of bacterial infections. transplant rejection.

Which of the following statements concerning antigen-presenting cells is true? They transport antigens to the liver, where they can be degraded. They are a type of T cell. They are involved in activating T cells. They are found only in lymphoid tissues.

Which type of T cell is involved in activating macrophages and stimulating development of cytotoxic T cells? TH2 cells CD8+ T cells Treg cells TH1 cells

Apoptosis results in significant leakage of cellular contents. True False

Which structure do antigen presenting cells utilize to directly help them present bacterial antigens? Phagolysosome Mitochondria Nucleus Golgi apparatus

Which of the following are likely to be found on an MHC-I protein? Damaged mitochondrial fragment Bacterial DNA Membranes from a neighboring dead host cell Bacterial flagella Bacterial cell wall fragment

What would a virally infected skin epithelial cell have on its cell surface? Class I MHC with skin cell antigens Class II MHC with liver cell antigens Class II MHC with macrophage antigens Class II MHC with viral antigens

Which of the following would you likely see on the surface of a human dendritic cell following phagocytosis of a bacterium? Class I MHC with dendritic cell antigens Class II MHC with dendritic cell antigens Class II MHC with engulfed bacterial antigens Class I MHC with dendritic cell antigens and Class II MHC with engulfed bacteria

Tom has a genetic disorder in which he does not synthesize class I MHC proteins or functional NK cells. Which of the following statements would be true for Tom? Tom would be less susceptible to helminth infections. Tom would not be able to destroy virally-infected cells. Tom would be more susceptible to bacterial infections. Tom would not be able to produce antibodies against viruses.

Consider a helminthic infection in which an individual is colonized by a parasitic worm. The worm is too big to be engulfed by a phagocytic cell. How does the immune system respond? Antibodies bind to the worm and disrupt its plasma membrane. The worm gets coated with antibodies, which activate other cells in the immune system to secrete chemicals that kill it. Blood flow is reduced to the area, which starves the worm of nutrients. Numerous phagocytes work cooperatively to ingest the worm.

Which of the following statements concerning immunological memory is true? The memory response is due to production of long-lived cells that can respond very rapidly upon second exposure. Antibodies produced in response to a secondary infection are mostly IgM. The memory response involves only B cells. The memory response is usually faster but not as strong.

What type of immunity results from vaccination? innate immunity naturally acquired active immunity naturally acquired passive immunity artificially acquired active immunity artificially acquired passive immunity

An individual may be exposed to a pathogen and become infected without actually getting sick. This is known as a subclinical infection. Even in subclinical infections, the individual's adaptive immune system can generate memory for the pathogen. What type of adaptive immunity is this? naturally acquired passive immunity naturally acquired active immunity artificially acquired passive immunity artificially acquired active immunity

Which cells are involved in a secondary response? Memory B cells T cells Plasma cells Memory B cells and plasma cells

How is the secondary response different from the primary response in terms of antibody concentration in the blood? The secondary response is faster, but does not produce more antibodies than the primary response. The secondary response is faster and produces more antibodies than the primary response. There is no difference with regard to antibody concentration in the blood. The secondary response is slower, but produces more antibodies than the primary response.

According to the animation, on which day does the production of IgG occur in the secondary response? Day ten Day two Day fifteen Day five

An anamnestic response is the term used to describe the production of antibodies from a plasma cell. another name for primary response. the appearance of antibodies in serum. another name for secondary response.

Which part of the adaptive immune response involves B cells? Neither humoral nor cell-mediated Both humoral and cell-mediated Cell-mediated Humoral

Antibodies are a part of which type of immunity? Cell-mediated Both humoral and cell-mediated Humoral Neither humoral nor cell-mediated