Question 1

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

Accepted Answer

A. is a way for a cell to give information about its activities.

Question 2

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

Accepted Answer

C. Non-phagocytic body cells can become infected with a virus.

Question 3

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

Accepted Answer

A. They present antigens from engulfed foreign cells.

Question 4

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

Accepted Answer

A. Phagolysosome

Question 5

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

Accepted Answer

A. Damaged mitochondrial fragment

Question 6

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

Accepted Answer

D. Class I MHC with skin cell antigens

Question 7

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

Accepted Answer

D. Class I MHC with dendritic cell antigens and Class II MHC with engulfed bacteria

Question 8

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?A. Tom would be less susceptible to helminth infections. B. Tom would not be able to destroy virally-infected cells. C. Tom would not be able to produce antibodies against viruses. D. Tom would be more susceptible to bacterial infections.

Accepted Answer

B. Tom would not be able to destroy virally-infected cells.

Question 9

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

Accepted Answer

B. They are involved in activating T cells.

Question 10

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

Accepted Answer

D. Humoral

Question 11

Antibodies are a part of which type of immunity?A. Cell-mediated B. Neither humoral nor cell-mediated C. Humoral D. Both humoral and cell-mediated

Accepted Answer

C. Humoral

Question 12

Phagocytosis is a process for engulfing large particles (>1&mu;m). Which feature of antibodies will help to make particles larger, therefore enhancing phagocytosis? A. opsonization B. neutralization C. agglutination D. complement activation

Accepted Answer

C. agglutination

Question 13

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? A. opsonization B. neutralization C. complement activation D. agglutination

Accepted Answer

B. neutralization

Question 14

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

Accepted Answer

B. B-cells, antigen, plasma cells

Question 15

If a patient has been exposed to an antigen for the first time, which class of immunoglobulin appears first?  IgG  IgE  IgM  IgD

Accepted Answer

IgM

Question 16

Which type of cell directly attacks infected cells?A. Bacterial cells B. Cancerous cells C. Helper T-cells D. Cytotoxic T-cells

Accepted Answer

D. Cytotoxic T-cells

Question 17

Immune cells that secrete cytokines and activate other immune cells are:A. Helper T-cells B. Abnormal body cells C. Cytotoxic T-cells D. Virally infected cells E. Invading pathogenic bacteria

Accepted Answer

A. Helper T-cells

Question 18

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

Accepted Answer

B. Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body.

Question 19

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

Accepted Answer

D. Helper T-cells produce cytokines to activate other cells of the immune system.

Question 20

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

Accepted Answer

D. Cellular immunity involves cells that recognize antigens and make specific antibodies against them.

Question 21

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

Accepted Answer

B. TH1 cells

Question 22

Number 10

Accepted Answer

...

Question 23

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? A. naturally acquired passive immunity B. artificially acquired active immunity C. artificially acquired passive immunity D. naturally acquired active immunity

Accepted Answer

D. naturally acquired active immunity

Question 24

Which cytokines are believed to contribute to autoimmune disease, such as rheumatoid arthritis? A. tumor necrosis factor (TNF) B. interferons C. hematopoietic cytokines D. chemokines

Accepted Answer

A. tumor necrosis factor (TNF) The tumor necrosis factor (TNF) family of cytokines are the ones that help to protect against tumors but also play a role in some autoimmune diseases.

Question 25

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? A. Blood flow is reduced to the area, which starves the worm of nutrients. B. Antibodies bind to the worm and disrupt its plasma membrane. C. The worm gets coated with antibodies, which activate other cells in the immune system to secrete chemicals that kill it. D. Numerous phagocytes work cooperatively to ingest the worm.

Accepted Answer

C. The worm gets coated with antibodies, which activate other cells in the immune system to secrete chemicals that kill it.

Question 26

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

Accepted Answer

A. The memory response is due to production of long-lived cells that can respond very rapidly upon second exposure.

Question 27

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

Accepted Answer

C. Each antibody has at least two antigen-binding sites.

Question 28

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

Accepted Answer

B. Plasma cells produce antibodies.

Question 29

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

Accepted Answer

C. The antibodies may block proteins necessary for binding the pathogen to the host, may opsonize the bacterium, or may agglutinate bacteria.

Question 30

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

Accepted Answer

D. On the surface of the cell

Question 31

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

Accepted Answer

B. They are small peptides, roughly 8-10 amino acids long.

Question 32

Which organelle assists directly with the presentation of MHC-I antigens?A. The endoplasmic reticulum B. The nucleus C. The Golgi apparatus D. The mitochondria E. The phagosome

Accepted Answer

A. The endoplasmic reticulum

Question 33

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

Accepted Answer

A. During the fusion of vesicles containing MHC-II proteins with vesicles containing digested pathogens

Question 34

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

Accepted Answer

D. Macrophages

Question 35

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

Accepted Answer

A. The process of programmed cell death.

Question 36

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

Accepted Answer

D. Bind to MHC molecules

Question 37

What is the fate of activated cytotoxic T-cells?A. Each activated cytotoxic T-cell proliferates, forming a clone of cells specific to the same antigen. B. They are destroyed via apoptosis. C. They are infected by viruses. D. They can differentiate into long-lived memory T-cells. E. 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. F. They can mature and attack infected cells.

Accepted Answer

E. 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.

Question 38

Which molecule triggers apoptosis?A. Gamma-interferon B. MHC C. Granzyme D. Perforin E. IL-2

Accepted Answer

C. Granzyme

Question 39

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

Accepted Answer

D. CD8 binds to MHC molecules of infected cells

Question 40

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

Accepted Answer

A. TCR

Question 41

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

Accepted Answer

D. B cells.

Question 42

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

Accepted Answer

C. MHC proteins

Question 43

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

Accepted Answer

C. After proliferation into a clonal population

Question 44

Natural killer cells are activated byA. TH2 cells. B. TH1 cells. C. antigen-presenting cells. D. bacterial cells.

Accepted Answer

B. TH1 cells.

Question 45

Which cells are involved in a secondary response?A. Memory B cells B. Plasma cells C. Memory B cells and plasma cells D. T cells

Accepted Answer

C. Memory B cells and plasma cells

Question 46

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

Accepted Answer

D. The secondary response is faster and produces more antibodies than the primary response.

Question 47

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

Accepted Answer

A. Day five

Question 48

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

Accepted Answer

A. another name for secondary response.

Question 49

Order the steps in the clonal expansion of antibodies and the production of antibodies.

Accepted Answer

1. Using its TCR, the Th cell recognizes the viral epitope displayed by the B cell.2. Cytokines produced by the Th cell activate the B cell, which divides giving rise to two cell types - memory cells and plasma cells. 3. Plasma cells secrete antibodies that recognize the virus.

Question 50

Number 21

Accepted Answer

Number 22

Question 51

Which of the following is the most likely possible diagnosis for Caleb? A. Sinus infection B. Flu C. Ear infection D. Common cold E. Mumps

Accepted Answer

C. Ear infection Hopefully, you recognized the signs and symptoms of an ear infection (otitis media, OM): pain and pressure in the ears or head, fever, and feeling wiggly, which we later deduced to be a 4-yr-old's way of describing the imbalance and dizziness he felt from his inner ear dysfunction! OM is responsible for millions of pediatric infections per year.

Question 52

While we usually think of fever as a bad thing, a fever is actually signifying that an immune response is progressing! Overall, which of the following cytokines would be most involved in increasing Caleb's fever response?A. Interleukin-4 B. Interleukin-1 C. Interleukin-2 D. Interleukin-10 E. Interleukin-12

Accepted Answer

B. Interleukin-1 When immune cells sense pathogens, certain components of the pathogen stimulate the innate cells to produce cytokines. When Interleukin-1 is produced, it acts on the hypothalamus to crank up the heat and results in fever and increased inflammatory processes. The other cytokines listed have separate functions such as T-cell responses (Interleukin-2), B-cell responses (Interleukin -4), anti-inflammation (Interleukin -10), or cell differentiation (Interleukin -12).

Question 53

The examination led to a diagnosis of otitis media (OM), or an ear infection. The picture on the left demonstrates a swollen, red eardrum with a fluid buildup behind the membrane. The immune processes most involved in the inflammation seen behind Caleb's eardrum would be attributed to:A. Lysis of red blood cells and allergic responses against platelets B. Destruction of all leukocytes and sudden cytokine storm responses C. Uncontrolled tissue necrosis due to pathogenic immune responses D. Vasodilation of capillaries and accumulation of immune cells, fluid or pus E. Reducing edema factors and increasing intravascular coagulation

Accepted Answer

D. Vasodilation of capillaries and accumulation of immune cells, fluid or pus The acute inflammatory processes provide noticeable signs, symptoms, and clinical clues such as pain, heat, and swelling to show that the body is attempting to fight the pathogen. This manifests when vasodilation increases blood flow to the area and produces erythema and edema. Specifically, edema is the result of the increased permeability of post-capillary venules as signaled by inflammatory cytokines and allows immune cells and microbe-fighting proteins to arrive at the area.

Question 54

Most patients would happily accept a prescription for antibiotics from the pediatrician and go home. But as a microbiologist, Dr. Trapper wanted to identify the infectious etiology and see what was going on inside his son. Even though it's not standard procedure for otitis media, he asked for some of the fluid contained behind the eardrum to be collected with a syringe (tympanocentesis) so he could analyze it for culture and sensitivity in his lab. He stained the fluid and examined it under the microscopic field. Interestingly, although he did not find any noticeable bacterial organisms, he did find high numbers of this characteristic responding cell type (picture), which could likely be identified as a:A. Neutrophil B. Macrophage C. Plasma cell D. Natural killer (NK) cell E. Dendritic cell

Accepted Answer

A. Neutrophil The appearance of the nucleus and cytoplasm of these cells would identify them as neutrophils (a.k.a. polymorphonuclear leukocytes or PMNs). They are part of the innate class of cells known as granulocytes which comprise a large percentage of responding innate cells. Increasing numbers of neutrophils, known as leukocytosis or raised white blood cell counts are often clinically important for diagnosis of acute bacterial infection, especially pyogenic infection. Often, these can be seen on common hospital lab reports as bands or shifts. These terms refer to immature neutrophils that are released from reserves in the bone marrow because they are needed to battle invading bacteria. Because they have not had enough time to 'grow up' they can be distinguished by phenotype and quantified. Neutrophils are some of the first responder cells that migrate the area of infection and their death results in the production of pus as noted in our patient, Caleb.

Question 55

Dr. Trapper wasn't going to give up easily and continued to scan the overall field for bacterial clues, but all he found were more immune cells. Soon, he noticed something else interesting...several cells were interacting! The likely identities of these cells based on morphologies could be best described as:A. Activated B cell and an antibody producing cell B. Macrophage and a platelet cell C. Adaptive immune cell and an antigen presenting cell D. Neutrophil and a complement cell E. Killer cell and an infected eardrum cell

Accepted Answer

C. Adaptive immune cell and an antigen presenting cell This interaction represents a critical turn in the immune response. The cell on the right (grey) is likely a lymphocyte, a component of the adaptive lines of defense. The cell on the left (purple) is an innate cell, likely a dendritic cell. This is probably representative of the interaction of an antigen-presenting cell (APC). The result of antigen presentation is to activate and bring powerful adaptive cells like B cells and T cells into the fight and provides tertiary immune responses such as antibody production (B cells), cytotoxicity (CD8 T cells), or 'helper/coordination' (CD4 T cells) functions. Without this APC interaction, the third line of defense would be inactive in our plight against antigen and our overall responses would suffer. Most other choices can be ruled out due to the phenotypic appearances.

Question 56

Caleb recovered without incident, but because there are millions of cases of ear infections every year in the U.S., Dr. Trapper wanted to make sure that this would not be the first of many recurrent ear infections for his son. He wanted to ensure that Caleb did not have an underlying immunodeficiency that would cause his future responses to fight antigens suboptimally. He asked the physician to do a serology analysis of Caleb, which consisted of probing for each antibody isotype found and to report how much is present. The analysis yielded the following results. What might you conclude from this?Probe Qualitative Result Anti-whole human antiserum +++ Anti-IgG ++ Anti-IgA ++ Anti-IgM + A. Caleb has a B cell deficiency B. Caleb has a normal response C. Caleb has SCID D. Caleb has a T cell deficiency E. Caleb has an autoimmune disorder

Accepted Answer

B. Caleb has a normal response Caleb's antibody response is perfect and producing as predicted! As the immune response progresses, we hope our responses become specialized to best combat the antigen. This includes adaptive immune activation and eventual memory responses. When we have T cell help (from CD4+ T cells) and plasma B cell responses, we fine-tune the response to make more productive antibody types. These changes produce better-qualified antibodies to bind the antigen via clonal selection and immunoglobulin class switching. Caleb's data shows he is producing large amounts of the efficient antibody, IgG, instead of the inefficient rookie antibody IgM.

Question 57

If this particular antigen attempts to re-infect Caleb, it's in for a bigger fight. By getting activation of adaptive immune cells such as B-cells and T-cells, the body generates an extra layer of protection. What is a critical advantage for Caleb the next time he encounters this antigen?A. Anamnestic (memory) responses and future vaccinations to augment the response B. Rates of ear infections (otitis media) are decreasing in the U.S. C. Innate immune components will be more abundant and quicker to respond D. Total immunity to the antigen once exposed and defeated by the body E. New, more potent antibiotics may be available as therapeutics to minimize need for immune responses

Accepted Answer

A. Anamnestic (memory) responses and future vaccinations to augment the response The major difference between innate responses and adaptive responses is the formation of memory cells Innate cells respond the same way each time. They search for simple antigenic patterns (pathogen-associated molecular patterns or PAMPs) and act on those patterns, and one cell can detect and respond to multiple antigens. Adaptive cells are specific for a single molecular pattern and tend to act even more effectively each time they encounter it.

Question 58

Which immunoglobulin class, found in blood, lymph, and the intestine, can cross the placenta and help to protect a fetus?  IgA  IgM  IgG  IgE

Accepted Answer

IgG

Question 59

What type of immunity results from vaccination? A. innate immunity B. naturally acquired active immunity C. naturally acquired passive immunity D. artificially acquired active immunity E. artificially acquired passive immunity

Accepted Answer

D. artificially acquired active immunity

Question 60

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

Accepted Answer

C. TH cell

Question 61

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

Accepted Answer

D. interaction between CD4+ and MHC II.

Question 62

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

Accepted Answer

A. neutralization.

Question 63

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

Accepted Answer

C. natural killer cells

Question 64

Which of the following statements is NOT a possible outcome of antigen-antibody reaction? A. clonal deletion B. ADCC C. activation of complement D. agglutination E. opsonization

Accepted Answer

A. clonal deletion

Microbiology Ch 17 - Study 1

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