Microbiology Ch 15, 16 Exercise 6

Which of the following are phagocytic cells found in the epidermis?

1. neutrophils

2. dendritic cells

3. microglia

4. wandering macrophages

5. natural killer lymphocytes

dendritic cells

Which of the following statements regarding the surface of the skin is false?

1. It is salty.

2. It has normal microbiota.

3. It has sebum as a coating.

4. It is acidic.

5. It has goblet cells.

It has goblet cells.

Which of the following contributes to protecting the eyes from microbial invasion?

1. A mucus layer traps and removes microbes.

2. Tears and mucus combine to trap microbes and remove them.

3. Tears mechanically flush particles from the eyes.

4. Tears contain lysozyme and salt.

5. Tears contain lysozyme and salt and mechanically flush particles from the eyes.

Tears contain lysozyme and salt and mechanically flush particles from the eyes.

Which of the following is the best definition of "microbial antagonism"?

1. the presence of normal microbiota that protect the body by competing with pathogens in a variety of ways to prevent pathogens from invading the body

2. the presence of resident bacteria on the surface of the body and in cavities that connect to the surface

3. the ability of microbiota to mutate into pathogens

4. the presence of pathogens on the surface of the skin, which will invade the body through abrasions

5. the presence of normal microbiota that can become pathogens under certain conditions

the presence of normal microbiota that protect the body by competing with pathogens in a variety of ways to prevent pathogens from invading the body

Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense against microbial invaders?

1. Both the mucus and the outer layer of cells are shed frequently.

2. The mucus contains a variety of antimicrobial chemicals and molecules.

3. The mucus is a physical trap that contains a variety of antimicrobial chemicals.

4. The mucus secreted by the mucous membrane physically traps microbes.

5. The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.

The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.

Which of the following characteristics is shared by the skin and mucous membranes?

1. They are both constantly shedding and replacing cells.

2. They both have cilia.

3. Lysozymes are always present.

4. The outer layers are composed of dead cells.

5. Sebum may be present.

They are both constantly shedding and replacing cells.

First line of defense may be described as

1. intact skin, mucous membranes, sebum, tears, and so forth.

2. the coating of a pathogen by complement.

3. damage resulting in cell lysis.

4. nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.

5. the release of prostaglandins and leukotrienes in response to microbes

intact skin, mucous membranes, sebum, tears, and so forth.

Sweat can cause damage to bacteria because it contains salt and lysozyme. T or F?

True

Which of the following areas of the body have mucous membranes?

1. urinary system

2. mouth

3. nasal cavity

4. mouth and nasal cavity

5. mouth, nasal cavity, and urinary system

mouth, nasal cavity, and urinary system

Antimicrobial peptides called ________ are secreted in sweat and damage bacteria and fungi.

1. antibodies

2. dermicidins

3. TLRs

4. complement factors

5. cytokines

dermicidins

Which of the following cells is a component of the body’s first line defense?

1. neutrophil

2. microglial cells

3. NK cell

4. goblet cell

5. monocyte

goblet cell

Which of the following proteins are part of the first line of defense against microbial invasion?

1. C3 and C5

2. NOD proteins

3. TLRs

4. interferons

5. dermacidins

dermacidins

The resident microbiota have no role in defense against pathogen invasion. T or F?

False

Response to specific pathogens that can improve with subsequent exposure is

1. the second line of defense.

2. microbial antagonism.

3. the first line of defense.

4. the third line of defense.

5. innate immunity.

the third line of defense.

Which of the following are chemotactic factors for phagocytes?

1. peptide fragments from complement

2. interferons and chemokines

3. chemokines

4. chemokines and peptide fragments from complement

5. interferons

chemokines and peptide fragments from complement

Which of the following statements about eosinophil function is true?

1. They are involved in the removal of neoplastic cells.

2. They secrete toxins onto virally infected cells.

3. They attach to the surface of parasitic helminths and produce toxins that kill the parasite.

4. They produce defensins.

5. They identify and spare normal cells.

They attach to the surface of parasitic helminths and produce toxins that kill the parasite.

The complement cascade and its by-products contribute to

1. triggering inflammation and release of interferons.

2. triggering release of interferons.

3. triggering inflammation.

4. attracting phagocytes to sites of infection.

5. both triggering inflammation and attracting phagocytes to sites of infection.

both triggering inflammation and attracting phagocytes to sites of infection.

Which of the following cells can use nonphagocytic means to kill bacteria?

1. eosinophils

2. neutrophils

3. natural killer cells

4. macrophages

5. both eosinophils and neutrophils

both eosinophils and neutrophils

Which of the following leukocytes have granules in their cytoplasm that stain blue with methylene blue?

1. monocytes

2. eosinophils

3. neutrophils

4. lymphocytes

5. basophils

basophils

Which cell becomes a macrophage when leaving the bloodstream?

1. eosinophil

2. basophil

3. neutrophil

4. monocyte

5. lymphocyte

monocyte

The components of the second line of defense against microbes may be characterized as

1. detecting the unique features of specific pathogens.

2. responders to invasion.

3. passive barriers.

4. mechanisms to strengthen the first line of defense.

5. both passive barriers and detecting specific pathogen features.

responders to invasion.

Which of the following are among the activities of neutrophils?

1. phagocytosis

2. formation of neutrophil extracellular traps

3. enzyme production that leads to the formation of nitric oxide

4. formation of neutrophil extracellular traps and phagocytosis

5. formation of neutrophil extracellular traps, phagocytosis, and production of nitric oxide

formation of neutrophil extracellular traps, phagocytosis, and production of nitric oxide

Which of the following statements regarding phagocyte recognition of pathogens is true?

1. NOD proteins on the surface of microbes are detected by TLRs.

2. MACs on the surface of microbes are detected by NOD proteins.

3. TLRs on the surface of microbes trigger the accumulation of opsonins.

4. TLRs in the phagocyte cytoplasmic membrane bind surface structures of microbes.

5. Lectins on the surface of microbes are bound by chemokine receptors.

TLRs in the phagocyte cytoplasmic membrane bind surface structures of microbes.

Alpha and beta interferons

1. produce no adverse effects in the body.

2. help protect virus-infected cells from the effects of the pathogen.

3. protect the cells that secrete them from being invaded by a virus.

4. produce active antiviral proteins (AVPs) that coat the surface of healthy cells and prevent the attachment of pathogenic viruses.

5. are produced by infected fibroblasts and macrophages.

are produced by infected fibroblasts and macrophages.

Which of the following substances stimulates the phagocytic activity of phagocytes?

1. alpha interferons

2. gamma interferons

3. antiviral proteins

4. leukotrienes

5. beta interferons

gamma interferons

Which of the following is NOT an example of a walled-off site of infection that contains a fluid made of dead and dying tissue cells, leukocytes, and pathogens?

1. a pustule

2. a pimple

3. a boil

4. a tumor

5. an abscess

a tumor

How does aspirin act to decrease the symptoms of inflammation?

1. It acts as an antiprostaglandin.

2. It is an antitoxoid for most microbial toxins.

3. It interferes with the action of interferons.

4. It blocks the release of histamine.

5. It prevents complement activation.

It acts as an antiprostaglandin.

The phenomenon known as chemotaxis is defined as

1. the coating of a pathogen by complement.

2. an increase in allergies and helminth infection.

3. the release of prostaglandins and leukotrienes in response to microbes.

4. the movement of a cell toward or away from a chemical stimulus.

5. the squeezing of cells through the lining of capillaries.

the movement of a cell toward or away from a chemical stimulus.

Opsonization is

1. phagocyte receptors detecting PAMPs.

2. the coating of a pathogen by complement to facilitate phagocytosis.

3. nonspecific leukocyte secretion of toxins onto the surface of virally infected cells.

4. damage resulting in cell lysis.

5. the sticking of monocytes to the wall of the blood vessels at the site of infection.

the coating of a pathogen by complement to facilitate phagocytosis.

Which of the following statements is true of eosinophils?

1. They decline during allergic reaction.

2. They secrete toxins onto the surface of helminth parasites.

3. They release prostaglandins and leukotrienes in response to microbes.

4. They produce the coating of a pathogen by complement.

5. They are in intact skin, sebum, tears, etc.

They secrete toxins onto the surface of helminth parasites.

TLRs are

1. present in intact skin, sebum, tears, etc.

2. the coatings of pathogens by complement.

3. nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.

4. molecules that damage cells, resulting in cell lysis.

5. phagocyte receptors that detect PAMPs.

phagocyte receptors that detect PAMPs.

The leukocytes called natural killer lymphocytes

1. are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.

2. respond to the coating of a pathogen by complement.

3. increase in allergies and helminth infection.

4. release prostaglandins and leukotrienes in response to microbes.

5. are specialists in killing bacteria.

are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.

Some toll-like receptors (TLRs) are found on the surface of host cells and recognize specific microbial molecules. T or F?

True

Histamine and prostaglandins are involved in inflammatory reactions. T or F?

True

The growth of some microbes is inhibited by elevated body temperature. T or F?

True

Neutrophils can kill bacteria by nonphagocytic mechanisms. T or F?

True

Which of the following cells increase in number during an infection with parasitic worms?

1. macrophages

2. lymphocytes

3. eosinophils

4. basophils

5. neutrophils

eosinophils

Cells of the second line of defense called ________ recognize and kill virus-infected cells.

1. eosinophils

2. NK cells

3. dendritic cells

4. basophils

5. macrophages

NK cells

The process of phagocytosis involve all of the following EXCEPT

1. vesicle fusion.

2. adhesion.

3. chemotaxis.

4. secretion of cytotoxins.

5. elimination.

secretion of cytotoxins.

Which of the following is an iron-binding protein produced by pathogens to access the body’s store of iron?

1. lactoferrin

2. ferritin

3. siderophores

4. transferrin

5. gastroferritin

siderophores

The alternative pathway of complement cascade activation begins with ________ binding to the surface of a microbe.

1. C5a

2. C1

3. complement factor B

4. C3a

5. C5b

complement factor B

Fever is beneficial during viral infection because the higher temperature

1. prevents viral infection of fibroblasts.

2. increases the effectiveness of interferons and phagocytes.

3. increases sweating and consequently the barrier effect.

4. inactivates interferons.

5. increases vasodilation, contributing to inflammation.

increases the effectiveness of interferons and phagocytes.

Which of the following substances contributes to the edema associated with inflammation?

1. interferon

2. leukotrienes

3. defensin

4. histamine

5. both leukotrienes and histamine

both leukotrienes and histamine

Which of the following are macrophage functions?

1. phagocytosis of pathogens and debris

2. release of alpha interferon

3. production of NETs

4. phagocytosis of pathogens and production of NETs

5. phagocytosis of pathogens and secretion of alpha interferons and leukotrienes

phagocytosis of pathogens and secretion of alpha interferons and leukotrienes

A type of lymphocyte called a(n) ________ detects cells with abnormal surface proteins and kills them.

1. NK cell

2. neutrophil

3. basophil

4. eosinophil

5. mast cell

NK cell

Microbial molecules detected by phagocytes are called

1. TLRs.

2. prostaglandins.

3. leukotrienes.

4. NODs.

5. PAMPs.

PAMPs

Interferons alpha and beta are effective against viruses. T or F?

True

Inflammation is an important part of the body’s first line of defense, and it involves migration of phagocytes to the area. T or F?

False

The white blood cells primarily responsible for adaptive immunity are

1. macrophages and eosinophils.

2. macrophages and neutrophils.

3. neutrophils and dendritic cells.

4. NK lymphocytes and neutrophils.

5. B lymphocytes and T lymphocytes.

B lymphocytes and T lymphocytes.

Adaptive immunity is sometimes also called acquired immunity. Which of the following statements provides a basis for the alternative name?

1. Lymphocytes of the adaptive immune system are highly specific for a single antigenic determinant.

2. Activated lymphocytes produce daughter cells that are identical in specificity and function.

3. Lymphocytes reactive to normal body components are removed.

4. To become activated, lymphocytes require exposure to the antigenic determinant for which they are specific.

5. Activated lymphocytes may persist for years in the body.

To become activated, lymphocytes require exposure to the antigenic determinant for which they are specific.

What type of immunity is produced by the body when a person contracts a disease?

1. naturally acquired passive immunity

2. naturally acquired active immunity

3. artificially acquired passive immunity

4. artificially acquired active immunity

5. innate immunity

naturally acquired active immunity

Vaccination triggers an immune response which produces ________ immunity.

1. artificial passive

2. natural passive

3. artificial active

4. natural active

5. both active and passive

artificial active

the figure illustrates an interaction between a(n) Hint: CD4 to MHC2

1. antigen presenting cell and a T lymphocyte.

2. antigen presenting cell and a B lymphocyte.

3. CTL and its target cell.

4. antigen presenting cell and a plasma cell.

5. NK cell and its target cell.

antigen presenting cell and a T lymphocyte.

Which of the following statements concerning plasma cells is FALSE?

1. They are descended from activated B cells.

2. They secrete a single type of antibody molecule specific for a single epitope.

3. They can produce large quantities of antibodies on a daily basis.

4. They live for many years and function as memory cells.

5. The antibodies they produce can remain in circulation for weeks.

They live for many years and function as memory cells.

Enhanced immune responses to subsequent exposures to an antigen to which the body has already been exposed are known as ________ responses.

1. autoimmune

2. primary immune

3. third-degree immune

4. memory

5. allergic

memory

Which of the following recognizes and binds to MHC I proteins and helps stabilize the binding of epitopes to T cell receptors?

1. CD8

2. CD4

3. CD26

4. CD95

5. MHC I

CD8

Which of the following statements regarding the cell-mediated immune response is TRUE?

1. A single cytotoxic T lymphocyte can kill many target cells.

2. Cytotoxic T lymphocytes do not require antigen presentation to become activated.

3. Helper T lymphocytes have no role in the activation of cytotoxic T lymphocytes.

4. Cytotoxic T lymphocytes kill by producing hydrogen peroxide.

5. Cytotoxic T lymphocytes interact with antibodies that have bound antigen to identify their target.

A single cytotoxic T lymphocyte can kill many target cells.

The perforin-granzyme pathway involves

1. binding CD95L to infected cells, which eventually leads to cell apoptosis.

2. presenting the foreign antigen to B cells.

3. the production of fever, which kills the pathogen.

4. the production of antibodies toward the invading pathogen.

5. the synthesis of special cell-killing proteins that act on infected or abnormal cells.

the synthesis of special cell-killing proteins that act on infected or abnormal cells.

The immunological synapse refers to the

1. interaction of the many cytokines produced by different immunological cells.

2. interaction between lymphocytes and foreign antigens to produce memory cells.

3. binding of a monocyte or macrophage to antigen so that it can act as an antigen-presenting cell.

4. activation of a B cell to become a plasma cell.

5. interaction between a T cell and an antigen-presenting cell to produce a specialized contact area for communication between these cells.

interaction between a T cell and an antigen-presenting cell to produce a specialized contact area for communication between these cells.

Which of the following cytokines promotes the development of a cell-mediated immune response?

1. IL-12

2. alpha interferon

3. IL-4 (interleukin-4)

4. tumor necrosis factor (TNF)

5. chemokines

IL-12

Which of the following is the result when a CTL interacts with a virally infected cell?

1. The cell releases interferon-gamma (INF-γ).

2. The CTL produces IL-12.

3. The cell undergoes apoptosis.

4. The cell produces MHC II with epitope attached.

5. The CTL produces oxidizing chemicals.

The cell undergoes apoptosis.

Which of the following is an exogenous antigen?

1. a noninfected human cell

2. a virus inside a cell

3. a bacterium outside a cell

4. a bacterium inside a cell

5. the malaria parasite inside a red blood cell

a bacterium outside a cell

Antigens are

1. enzymes secreted to destroy a pathogen’s cell wall.

2. proteins the body produces against invading substances.

3. specific molecules, or parts of molecules, that the body recognizes as foreign.

4. proteins on the surface of our cells to which pathogens attach.

5. cells that protect the body against invaders.

specific molecules, or parts of molecules, that the body recognizes as foreign.

You step on something in the yard resulting in a puncture wound that does not bleed freely. Antigens from any microbes that entered the wound will most likely end up in the

1. lymph nodes of the neck (cervical).

2. lymph nodes of the armpit (axilla).

3. appendix.

4. lymph nodes of the groin.

5. spleen.

lymph nodes of the groin.

The type of immunoglobulin illustrated in the figure is
Hint: 5 Y shape

1. IgM.

2. IgD.

3. IgA.

4. IgE.

5. IgG.

IgM

The antibody-binding site of an antibody is made up of

1. the variable regions of both light and heavy chains.

2. the variable regions of the heavy chains.

3. one heavy chain.

4. portions of both of the heavy chains only.

5. the light chains only.

the variable regions of both light and heavy chains

Secretory IgA antibodies are unique because they

1. are present in lymph nodes.

2. have unique light chains.

3. are present in the plasma.

4. are connected with J chains and short polypeptides to form dimers.

5. are Y-shaped molecules.

are connected with J chains and short polypeptides to form dimers.

Which of the following function in agglutination?

1. IgG antibodies

2. IgD antibodies

3. IgA antibodies

4. IgE antibodies

5. IgA and IgG antibodies

IgA and IgG antibodies

The most prevalent type of antibody in the blood is

1. IgM.

2. IgA.

3. IgG.

4. IgE.

5. IgD.

IgG

Which of the following statements about T lymphocytes is FALSE?

1. T lymphocytes have TCRs that recognize antigen only if it is bound to MHC.

2. T lymphocytes directly attack cells and produce the cell-mediated immune response.

3. T lymphocytes produce antibody molecules.

4. T lymphocytes are called such because they mature in the thymus.

5. There are three types of T lymphocytes.

T lymphocytes produce antibody molecules.

Which of the following cytokines act as a signal between leukocytes?

1. interferons

2. growth factors

3. chemokines

4. interleukins

5. tumor necrosis factors

interleukins

Major histocompatibility antigens are

1. antigens attached to foreign invaders.

2. antigens that must be processed to be recognized by the immune system.

3. autoantigens involved in epitope recognition.

4. antigens that provoke allergic reactions.

5. not really antigens, but rather antibodies produced to mask foreign antigens.

autoantigens involved in epitope recognition.

Class II MHC are found on

1. muscle cells.

2. professional antigen-presenting cells.

3. red blood cells.

4. the skin.

5. cytoplasmic membranes of nucleated cells.

professional antigen-presenting cells.

Class I MHC molecules are essential for

1. detection of IL-2.

2. recognition of class II MHC.

3. presentation of endogenous antigens.

4. recognition of chemokines.

5. presentation of exogenous antigens.

presentation of endogenous antigens.

What is the role of interleukins?

1. chemotaxis of leukocytes

2. production of virally infected cells

3. signaling between leukocytes

4. complement activation

5. ensuring production of enough leukocytes

signaling between leukocytes

What is the result when a dendritic cell phagocytizes a microbe and processes it?

1. display of microbial epitope-MHC II complexes on the cell surface

2. display of microbial fragments with CD8 glycoproteins

3. activation of the dendritic cell to become a plasma cell

4. display of epitope-MHC I complexes on the surface of the cell

5. suppression of the immune response to the microbe

display of microbial epitope-MHC II complexes on the cell surface

Large molecules such as polymers make good antigens. T or F?

False

Cytokines are soluble regulatory proteins that act as intercellular signals and include substances such as interleukins, interferon, and growth factors. T or F?

True

Immature B lymphocytes undergo clonal deletion in the bone marrow. T or F?

True

The MALT lacks the tough outer capsule of a lymph node but functions in the same way. T or F?

True

A single B lymphocyte can recognize multiple antigenic determinants. T or F?

False

During an infection with Listeria, an intracellular bacterium, APCs will present antigen on MHC II molecules. T or F?

False