Chapter 17 Pre-Lecture Quiz Questions

Which structure do antigen presenting cells utilize to directly help them present bacterial antigens?
Which of the following are likely to be found on an MHC-I protein?
Bacterial cell wall fragment
Bacterial flagella
Bacterial DNA
Damaged mitochondrial fragment
Membranes from a neighboring dead host cell
Damaged mitochondrial fragment
What would a virally infected skin epithelial cell have on its cell surface?
Class II MHC with liver cell antigens
Class II MHC with macrophage antigens
Class II MHC with viral antigens
Class I MHC with skin cell antigens
Class I MHC with skin cell 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 I MHC with dendritic cell antigens and Class II MHC with engulfed bacteria
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. Which of the following statements would be true for Tom?
Tom would be more susceptible to bacterial infections.
Tom would be less susceptible to helminth infections.
Tom would not be able to destroy virally-infected cells.
Tom would not be able to produce antibodies against viruses.
Tom would not be able to destroy virally-infected cells.
Phagocytosis is a process for engulfing large particles (>1μm). Which feature of antibodies will help to make particles larger, therefore enhancing phagocytosis?
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?
__________________ stimulated with ___________ differentiate into __________, which secrete antibodies into the bloodstream.
B-cells, antigen, plasma cells
Which type of cell directly attacks infected cells?
cytotoxic t-cells
Cytokines are produced by which of the following cells?
Abnormal body cells
Virally infected cells
Invading pathogenic bacteria
Helper T-cells
Cytotoxic T-cells
helper t-cells
HIV directly infects T-cells. Why is this problematic for cell-mediated immunity?
Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body.
How do helper T-cells and cytotoxic T-cells work together?
Helper T-cells produce cytokines to activate other cells of the immune system.
Which of the following best characterizes clonal selection?
The production of identical B cells producing the same antibody
What is produced by the process of clonal expansion?
plasma cells and memory B cells
An antigen that is potent enough to activate a B cell on its own is known as
T-independent antigen
Based on the animation, T cells recognized the antigen displayed by what protein of the B cell?
How can a sufficient humoral immune response occur if a plasma cell only lives for a few days?
Each plasma cell can produce up to 2000 antibodies every second.
What makes agglutination by antibodies possible?
Each antibody has at least two antigen-binding sites.
What is the role of plasma cells in humoral immunity?
they produce antibodies
How might a pathogenic bacterium be affected by antibodies?
block proteins necessary for binding the pathogen to the host, may opsonize the bacterium, or may agglutinate bacteria.
Which receptor on the helper T-cell recognizes the specific antigen from an antigen-presenting cell?
TH2 cells produce cytokines that activate
Which proteins on the antigen-presenting cell are recognized by the helper T-cell?
MHC proteins
When do helper T-cells develop into TH1 or TH2 cells?
After proliferation into a clonal population
Natural killer cells are activated by
TH1 cells
What is apoptosis?
programmed cell death
What is the function of the CD8 receptor?
bind to MHC molecules
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.
Which molecule triggers apoptosis?
Which event happens first during cytotoxic T-cell activation?
CD8 binds to MHC molecules of infected cells
Where are MHC molecules located on a cell?
on the surface of the cell
What is a feature of the small fragments presented by MHC-I proteins?
small polypeptide chains of 8-10 amino acids
Which organelle assists directly with the presentation of MHC-I antigens?
endoplasmic reticulum
When does MHC-II loading occur?
during the fusion of vesicles containing MHC-II proteins with vesicles containing digested pathogens
Which of the cells listed below can present antigens on Class II MHC proteins?