Exam 3 (Multiple Choice Questions) COPY Flashcards
A commensal bacterium
A) Does not receive any benefit from its host.
B) Is beneficial to its host.
C) May be an opportunistic pathogen.
D) Does not infect its host.
E) B and D only.
C) May be an opportunistic pathogen.
Innate immunity is
A) The body’s ability to ward off diseases.
B) The body’s defenses against any kind of pathogen.
C) The body’s defense against a particular pathogen.
D) The lack of resistance.
E) None of the above.
B)The body’s defenses against any kind of pathogen
Which of the following is not a physical factor to protect the skin and mucous membranes from infection? A) Layers of cells
B) Tears
C) Saliva
D) Lysozyme
E) None of the above
D) Lysozyme
The function of the “ciliary escalator” is to
A) Kill microorganisms.
B) Remove microorganisms from body cavities.
C) Remove microorganisms from the lower respiratory tract.
D) Remove microorganisms from the upper respiratory tract.
E) All of the above.
C) Remove microorganisms from the lower respiratory tract.
Which of the following is not a characteristic of inflammation?
A) Redness
B) Pain
C) Local heat
D) Fever
E) Swelling
D)Fever
The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway beginning with the activation of
A) C1
B) C2
C) C3
D) C5
E) C6
C)C3
Which of the following does not cause vasodilation?
A) Kinins
B) Prostaglandins
C) Lysozymes
D) Histamine
E) None of the above
C)Lysozymes
“Margination” refers to
A) The adherence of phagocytes to microorganisms.
B) The chemotactic response of phagocytes.
C) Adherence of phagocytes to the lining of blood vessels.
D) Dilation of blood vessels.
E) The movement of phagocytes through walls of blood vessels.
C) Adherence of phagocytes to the lining of blood vessels.
Which of the following is not an effect of complement activation?
A) Interference with viral replication
B) Bacterial cell lysis
C) Opsonization
D) Increased phagocytic activity
E) Increased blood vessel permeability
A) Interference with viral replication
Normal microbiota provide protection from infection by all of the following except
A) They provide antibacterial chemicals.
B) They out-compete newcomers.
C) They make the chemical environment unsuitable for nonresident bacteria.
D) They produce lysozyme.
E) None of the above.
D) They produce lysozyme.
Which of the following does not provide protection from phagocytic digestion?
A) Preventing formation of phagolysosomes
B) Killing white blood cells
C) Lysing phagolysosomes
D) Ability to grow at a low pH
E) None of the above
E) None of the above
Defensive cells such as T cells identify pathogens by binding:
A) Toll-like receptors.
B) Lysozyme.
C) Complement.
D) Lectins.
E) Cytokines.
A) Toll-like receptors.
Which of the following is not a chemical factor to protect the skin and mucous membranes from infection? A) Mucus
B) Sebum
C) Gastric juices
D) pH
E) Lysozyme
A) Mucus
Adherence of phagocytes may be accomplished by all of the following except
A) Trapping a bacterium against a rough surface.
B) Opsonization.
C) Chemotaxis.
D) Lysozyme.
E) Complement.
D) Lysozyme.
Which of the following is not an effect of histamine?
A) Vasodilation
B) Fever
C) Swelling
D) Redness
E) Pain
B) Fever
Which of the following is not a function of inflammation?
A) To destroy an injurious agent
B) To remove an injurious agent
C) To wall off an injurious agent
D) To repair damaged tissue
E) None of the above
E) None of the above
Chill is a sign that
A) Body temperature is falling.
B) Body temperature is rising.
C) Body temperature will remain the same.
D) Sweating will follow.
E) None of the above.
B) Body temperature is rising.
Activation of C3a results in all of the following except
A) Acute inflammation.
B) Increased blood vessel permeability.
C) Fever.
D) Attraction of phagocytes.
E) None of the above.
C) Fever.
Vasodilation is caused by all of the following except
A) Histamine.
B) Complement.
C) Prostaglandins.
D) Leukotrienes.
E) None of the above.
B) Complement.
Which of the following is involved in adaptive immunity?
A) Basophil
B) Eosinophil
C) Lymphocyte
D) Monocyte
E) Neutrophil
C) Lymphocyte
Which one of the following is not an effect of fever?
A) Increases production of T cells.
B) Increases interferon activity.
C) Increases transferrin production.
D) Kills pathogens.
E) All are effects of fever.
D) Kills pathogens.
Which of the following statements is true?
A) Symbiosis refers to different organisms living together.
B) Members of a symbiotic relationship cannot live without each other.
C) A parasite is not in symbiosis with its host.
D) Symbiosis refers to different organisms living together and benefiting from each other. E) At least one member must benefit in a symbiotic relationship.
A) Symbiosis refers to different organisms living together.
A nosocomial infection is
A) Always present but in apparent at the time of hospitalization.
B) Acquired during the course of hospitalization.
C) Always caused by medical personnel.
D) Only a result of surgery.
E) Always caused by pathogenic bacteria.
B) Acquired during the course of hospitalization.
The major significance of Koch's work was that
A) Microorganisms are present in a diseased animal.
B) Diseases can be transmitted from one animal to another.
C) Microorganisms can be cultured.
D) Microorganisms cause disease.
E) Microorganisms are the result of disease.
D) Microorganisms cause disease.
Koch’s postulates don’t apply to all diseases because
A) Some microorganisms can’t be cultured in laboratory media.
B) Some microorganisms do’t cause the same disease in laboratory animals.
C) Some microorganisms cause different symptoms under different conditions.
D) Some microorganisms can’t be observed.
E) All diseases aren’t caused by microorganisms.
E) All diseases aren’t caused by microorganisms.
Which of the following diseases is not spread by droplet infection?
A) Botulism
B) Tuberculosis
C) Measles
D) Common cold
E) Diphtheria
A) Botulism
Mechanical transmission differs from biological transmission in that mechanical transmission
A) Doesn’t require an arthropod.
B) Involves fomites.
C) Doesn’t involve specific diseases.
D) Requires direct contact.
E) Doesn’t work with non communicable diseases.
C) Doesn’t involve specific diseases.
Which of the following definitions is incorrect?
A) Endemic a disease that is constantly present in a population
B) Epidemic fraction of the population having a disease at a specified time
C) Pandemic a disease that affects a large number of people in the world in a short time
D) Sporadic a disease that affects a population occasionally
E) None of the above
B) Epidemic fraction of the population having a disease at a specified time
Which of these infections can cause septicemia?
A) Bacteremia
B) Focal infection
C) Local infection
D) Septicemia
E) Systemic infection
B) Focal infection
Which type of infection can be caused by septicemia?
A) Bacteremia
B) Focal infection
C) Local infection
D) Septicemia
E) Systemic infection
E) Systemic infection
Koch observed Bacillus anthracis multiplying in the blood of cattle. What is this condition called?
A) Bacteremia
B) Focal infection
C) Local infection
D) Septicemia
E) Systemic infection
D) Septicemia
Nosocomial infections are most often caused by
A) Escherichia coli.
B) Staphylococcus aureus.
C) Enterococcus.
D) Pseudomonas.
E) Klebsiella.
A) Escherichia coli.
Transient microbiota differ from normal microbiota because transient microbiota
A) Cause diseases.
B) Are found in a certain location on the host.
C) Are acquired by direct contact.
D) Are present for a relatively short time.
E) None of the above.
D) Are present for a relatively short time.
Which of the following statements about nosocomial infections is not true?
A) They occur in compromised patients.
B) They are caused by opportunists.
C) They are caused by drug-resistant bacteria.
D) They are caused by normal microbiota.
E) None of the above.
B) They are caused by opportunists.
One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in
A) Body odor.
B) Fewer diseases.
C) Increased susceptibility to disease.
D) Normal microbiota returning immediately.
E) No bacterial growth because washing removes their food source.
C) Increased susceptibility to disease.
Which of the following is not a reservoir of infection?
A) A sick person
B) A healthy person
C) A sick animal
D) A hospital
E) None of the above
E) None of the above
All of the following are communicable diseases except
A) Malaria.
B) AIDS.
C) Tuberculosis.
D) Tetanus.
E) Typhoid fever.
D) Tetanus.
Which of the following is a fomite?
A) Water
B) Droplets from a sneeze
C) Pus
D) Insects
E) A hypodermic needle
E) A hypodermic needle
All of the following statements about biological transmission are true except
A) The pathogen reproduces in the vector.
B) The pathogen may enter the host in the vector's feces.
C) Houseflies are an important vector.
D) The pathogen may be injected by the bite of the vector.
E) The pathogen may require the vector as a host.
C) Houseflies are an important vector.
Which of the following definitions is incorrect?
A) Acute a short-lasting primary infection
B) Inapparent infection characteristic of a carrier state
C) Chronic a disease that develops slowly and lasts for months
D) Primary infection an initial illness
E) Secondary infection a long-lasting illness
E) Secondary infection a long-lasting illness
Symptoms of disease differ from signs of disease in that symptoms
A) Are changes felt by the patient.
B) Are changes observed by the physician.
C) Are specific for a particular disease.
D) Always occur as part of a syndrome.
E) None of the above.
A) Are changes felt by the patient.
The science that deals with when diseases occur and how they are transmitted is called
A) Ecology.
B) Epidemiology.
C) Communicable disease.
D) Morbidity and mortality.
E) Public health.
B) Epidemiology.
Figure 14.1 shows the incidence of influenza during a typical year. Which letter on the graph indicates the endemic level?
A) a
B) b
C) c
D) d
E) None of the above
D) d
Emergence of infectious diseases can be due to all of the following except
A) Antibiotic resistance.
B) Climatic changes.
C) Digging up soil.
D) Microbes trying to cause disease.
E) Travel.
D) Microbes trying to cause disease.
Which of the following pairs is mismatched?
A) Malaria vector
B) Salmonellosis vehicle transmission
C) Syphilis direct contact
D) Influenza droplet infection
E) None of the above
E) None of the above
All of the following can contribute to postoperative infections except
A) Using syringes more than once.
B) Normal microbiota on the operating room staff.
C) Errors in aseptic technique.
D) Antibiotic resistance.
E) None of the above.
E) None of the above.
In Figure 14.2, what is the endemic level of rotavirus infections?
A) 0%
B) Approximately 10%
C) Approximately 20%
D) 35%
E) The month of January
B) Approximately 10%
A cold transmitted by a facial tissue is an example of
A) Direct contact
B) Droplet transmission
C) Fomite
D) Vector
E) Vehicle transmission
E) Vehicle transmission
Influenza transmitted by an unprotected sneeze is an example of
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmission.
B) Droplet transmission.
A sexually transmitted disease is an example of
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmission.
A) Direct contact.
Gastroenteritis acquired from roast beef is an example of
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmission.
E) Vehicle transmission.
A needlestick is an example of
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmission.
C) Fomite.
Legionellosis transmitted by a grocery store mist machine is an example of
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmission.
E) Vehicle transmission.
Plague transmitted by a flea is an example of
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmission.
D) Vector.
The most likely mode of transmission of pneumonic plague between humans is
A) Direct contact.
B) Droplet transmission.
C) Fomite.
D) Vector.
E) Vehicle transmission.
B) Droplet transmission.
Which one of the following is not an example of microbial antagonism?
A) Acid production by bacteria
B) Bacteriocin production
C) Bacteria occupying host receptors
D) Bacteria causing disease
E) None of the above
E) None of the above
The yeast Candida albicans does not normally cause disease because of
A) Symbiotic bacteria.
B) Antagonistic bacteria.
C) Parasitic bacteria.
D) Commensal bacteria.
E) None of the above.
B) Antagonistic bacteria.
Haemophilus bacteria require heme protein produced by Staphylococcus bacteria. This is an example of A) Antagonism.
B) Commensalism.
C) Parasitism.
D) Synergism.
E) None of the above.
D) Synergism.
Which one of the following does not contribute to the incidence of nosocomial infections?
A) Formation of biofilms.
B) Lapse in aseptic techniques.
C) Gram-negative cell walls.
D) Lack of hand-washing.
E) Lack of insect control.
C) Gram-negative cell walls.
The most frequently used portal of entry for pathogens is the
A) Mucous membranes of the respiratory tract.
B) Mucous membranes of the gastrointestinal tract.
C) Skin.
D) Parenteral route.
E) All are used equally.
A) Mucous membranes of the respiratory tract.
Which of the following diseases is not usually contracted by the respiratory route?
A) Pneumonia
B) Infectious hepatitis
C) Tuberculosis
D) Measles
E) None of the above
B) Infectious hepatitis
Most pathogens that gain access through the skin
A) Can penetrate intact skin.
B) Just infect the skin itself.
C) Enter through hair follicles and sweat ducts.
D) Must adhere first while their invasive factors allow them to penetrate.
E) Must be injected.
C) Enter through hair follicles and sweat ducts.
The ID50 is a A) Measure of pathogenicity.
B) Dose that will cause an infection in 50% of the test population.
C) Dose that will kill some of the test population.
D) Dose that will cause an infection in some of the test population.
E) Dose that will kill 50% of the test population.
B) Dose that will cause an infection in 50% of the test population.
Which of the following does not contribute to a pathogen's invasiveness?
A) Toxins
B) Capsule
C) Cell wall
D) Hyaluronidase
E) Ligands
A) Toxins
Which of the following statements is false?
A) Leukocidins destroy neutrophils.
B) Hemolysins lyse red blood cells.
C) Hyaluronidase breaks down substances between cells.
D) Kinase destroys fibrin clots.
E) Coagulase destroys blood clots.
E) Coagulase destroys blood clots.
Which of the following statements about exotoxins is generally not true?
A) They are more potent than endotoxins.
B) They are composed of proteins.
C) They are not destroyed by heat.
D) They have specific methods of action.
E) They are produced by gram-positive bacteria.
C) They are not destroyed by heat.
Endotoxins are
A) Associated with gram-positive bacteria.
B) Specific in their method of action.
C) Part of the gram-negative cell wall.
D) Excreted from the cell.
E) None of the above.
C) Part of the gram-negative cell wall.
Which of the following is not a membrane-disrupting toxin?
A) A-B toxin
B) Hemolysin
C) Leucocidin
D) Streptolysin O
E) Streptolysin S
A) A-B toxin
Cytopathic effects are changes in host cells due to
A) Viral infections.
B) Protozoan and helminthic infections.
C) Fungal infections.
D) Bacterial infections.
E) All of the above.
A) Viral infections.
Which of the following does not contribute to the symptoms of a fungal disease?
A) Capsules
B) Toxins
C) Allergic response of the host
D) Cell walls
E) None of the above
D) Cell walls
All of the following are methods of avoiding host antibodies except
A) Antigenic change.
B) IgA protease.
C) Invasims.
D) Membrane-disrupting toxins.
E) None of the above
D) Membrane-disrupting toxins.
Siderophores are bacterial proteins that compete with animal
A) Antibodies.
B) Red blood cells.
C) Transferrin.
D) White blood cells.
E) None of the above.
C) Transferrin.
All of the following may be used for adherence except
A) Fimbriae.
B) Cell membrane mannose.
C) Glycoproteins.
D) Lipoproteins.
E) Capsules.
B) Cell membrane mannose.
Which of the following is not considered entry via the parenteral route?
A) Injection
B) Bite
C) Surgery
D) Hair follicle
E) None of the above
D) Hair follicle
A cell wall can increase a bacterium's virulence because cell wall lipid A
A) Resists phagocytosis.
B) Helps the bacterium attach.
C) Destroys host tissues.
D) All bacteria have a cell wall and all are not pathogenic; therefore, cell walls do not contribute to virulence.
E) None of the above.
E) None of the above.
Botulism is caused by an exotoxin, therefore it could easily be prevented by
A) Boiling food prior to consumption.
B) Administering antibiotics to patients.
C) Not eating canned food.
D) Preventing fecal contamination of food.
E) None of the above.
A) Boiling food prior to consumption.
Which of the following organisms doesn't produce an exotoxin?
A) Salmonella typhi
B) Clostridium botulinum
C) Corynebacterium diphtheriae
D) Clostridium tetani
E) Staphylococcus aureus
A) Salmonella typhi
Which of the following cytopathic effects is cytocidal?
A) Inclusion bodies
B) Giant cells
C) Antigenic changes
D) Transformation
E) Release of enzymes from lysosomes
E) Release of enzymes from lysosomes
The symptoms of tetanus are due to
A) Encapsulated Clostridium tetani.
B) The growth of Clostridium tetani in a wound.
C) Hemolysins produced by Clostridium tetani.
D) An exotoxin produced by Clostridium tetani.
E) All of the above.
D) An exotoxin produced by Clostridium tetani.
Symptoms of protozoan and helminthic diseases are due to
A) Tissue damage due to growth of the parasite on the tissues.
B) Waste products excreted by the parasite.
C) Products released from damaged tissues.
D) All of the above.
E) None of the above.
D) All of the above.
Which of the following is not true of staphylococcal enterotoxin?
A) It causes vomiting.
B) It causes diarrhea.
C) It is an exotoxin.
D) It is produced by Staphylococcus aureus growing in the host's intestines.
E) None of the above.
D) It is produced by Staphylococcus aureus growing in the host's intestines.
Which of the following does not contribute to the virulence of a pathogen?
A) Numbers of microorganisms that gain access to a host
B) Cell wall
C) Toxins
D) Enzymes
E) None of the above
E) None of the above
Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages
A) Give new gene sequences to the host bacteria.
B) Produce toxins.
C) Carry plasmids.
D) Kill the bacteria causing release of endotoxins.
E) All of the above.
A) Give new gene sequences to the host bacteria.
Thirty-two people in San Francisco who ate jackfish caught at Midway Island developed malaise, nausea, blurred vision, breathing difficulty, and numbness from 3 to 6 hours after eating. The most likely cause of this food intoxication is
A) A mycotoxin.
B) Aflatoxin.
C) Staphylococcal enterotoxin.
D) Ciguatera.
E) Cholera toxin.
D) Ciguatera.
All of the following are true about M protein except
A) It is found on Streptococcus pyogenes.
B) It is found on fimbriae.
C) It is heat- and acid-resistant.
D) It is readily digested by phagocytes.
E) It is a protein.
D) It is readily digested by phagocytes.
Septic shock due to gram-positive bacteria is caused by
A) A-B toxins.
B) Lipid A.
C) Membrane-disrupting toxins.
D) Superantigens.
E) All of the above.
D) Superantigens.
A needlestick is an example of which portal of entry?
A) Skin
B) Parenteral route
C) Mucous membranes
D) All of the above
E) None of the above
B) Parenteral route
Poliovirus is ingested and gains access to tissues by which portal of entry?
A) Skin
B) Parenteral
C) Mucous membranes
D) All of the above
E) None of the above
C) Mucous membranes
Pseudomonas aeruginosa produces a two-part exotoxin. The most likely pathologic effect of this toxin is
A) Inhibition of protein synthesis.
B) Flaccid paralysis.
C) Tetani or lockjaw.
D) A red rash.
E) The bacteria will be able to grow in phagocytes.
A) Inhibition of protein synthesis.
Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides were removed
A) Polypeptide A would bind to target cells.
B) Polypeptide A would enter the cells.
C) Polypeptide B would not be able to enter the cells.
D) Vibrio would not produce cholera toxin.
E) None of the above.
C) Polypeptide B would not be able to enter the cells.
Which is a method of avoiding phagocytosis?
A) Producing fimbriae
B) Inducing endocytosis
C) Producing toxins
D) Inducing TNF
E) All of the above
B) Inducing endocytosis
The mechanism by which gram-negative bacteria can cross the blood-brain barrier.
A) Producing fimbriae
B) Inducing endocytosis
C) Producing toxins
D) Inducing TNF
E) All of the above
D) Inducing TNF
Injectable drugs are tested for endotoxins by
A) The Limulus amoebocyte lysate test.
B) Counting the viable bacteria.
C) Filtering out the cells.
D) Looking for turbidity.
E) None of the above.
A) The Limulus amoebocyte lysate test.
Endotoxins in injectable drugs could cause
A) Infection.
B) Septic shock.
C) Giant cell formation.
D) Nerve damage.
E) All of the above.
D) Nerve damage.
Gram-negative septic shock results from the following events. What is the second step?
A) Body temperature is reset in the hypothalamus.
B) Fever occurs.
C) IL-1 is released.
D) LPS is released from gram-negative bacteria.
E) Phagocytes ingest gram-negative bacteria.
D) LPS is released from gram-negative bacteria.
Antibiotics can lead to septic shock if used to treat
A) Viral infections.
B) Gram-negative bacterial infections.
C) Gram-positive bacterial infections.
D) Protozoan infections.
E) Helminth infestations.
B) Gram-negative bacterial infections.
Which of the following is not a cytopathic effect of viruses?
A) Cell death
B) Host cells fuse to form multinucleated syncytia
C) Inclusion bodies form in the cytoplasm or nucleus
D) Increased cell growth
E) None of the above
E) None of the above
Which of the following organisms causes the most severe disease?
A) E. coli O157:H7 ID50-20
B) Rhinovirus ID50-200
C) Shigella ID50-10
D) Treponema pallidum ID50-57
E) Can’t tell
E) Can’t tell
The administration of ampicillin before surgery
A) Decreases the risk of staphylococcal infection.
B) Increases the risk of staphylococcal infection.
C) Has no effect on risk of infection.
D) Replaces tetracycline.
E) Can’t tell.
A) Decreases the risk of staphylococcal infection.
Which organism most easily causes an infection?
A) E. coli O157:H7 ID50-20
B) Legionella pneumophila ID50-1
C) Shigella ID50-10
D) Treponema pallidum ID50-57
E) Can’t tell
B) Legionella pneumophila ID50-1
Bacteria that cause periodontal disease have adhesins for receptors on streptococci that colonize on teeth. This indicates that
A) Streptococci get bacterial infections.
B) Streptococcal colonization is necessary for periodontal disease.
C) Bacteria that cause periodontal disease adhere to gums and teeth.
D) Bacteria that cause periodontal disease adhere to teeth.
E) Streptococci cause periodontal disease.
B) Streptococcal colonization is necessary for periodontal disease.
Nonpathogenic V. cholerae can acquire the cholera toxin gene by
A) Phagocytosis.
B) Transduction.
C) Conjugation.
D) Transformation. E) None of the above.
B) Transduction.
In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes
A) The disease to subside.
B) A decrease in blood pressure.
C) A fever.
D) A gram-negative infection.
E) None of the above.
B) A decrease in blood pressure.
Which of the following is not used for attachment to a host?
A) M protein
B) Ligands
C) Fimbriae
D) Capsules
E) None of the above.
E) None of the above.
Type of immunity resulting 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
D) Artificially acquired active immunity
Type of immunity resulting from transfer of antibodies from one individual to a susceptible individual by means of injection.
A) Innate immunity
B) Naturally acquired active immunity
C) Naturally acquired passive immunity
D) Artificially acquired active immunity
E) Artificially acquired passive immunity
E) Artificially acquired passive immunity
Immunity resulting from recovery from mumps.
A) Innate immunity
B) Naturally acquired active immunity
C) Naturally acquired passive immunity
D) Artificially acquired active immunity
E) Artificially acquired passive immunity
B) Naturally acquired active immunity
Newborns' immunity due to the transfer of antibodies across the placenta.
A) Innate immunity
B) Naturally acquired active immunity
C) Naturally acquired passive immunity
D) Artificially acquired active immunity
E) Artificially acquired passive immunity
C) Naturally acquired passive immunity
Immunity that is not due to antibodies.
A) Innate immunity
B) Naturally acquired active immunity
C) Naturally acquired passive immunity
D) Artificially acquired active immunity
E) Artificially acquired passive immunity
A) Innate immunity
T cells are activated by:
A) Interaction between CD4 and MHC II.
B) Interaction between TCRs and MHC II.
C) Cytokines released by dentritic cells.
D) Cytokines released by B cells.
E) Complement.
A) Interaction between CD4 and MHC II.
Which of the following recognizes antigens displayed on host cells with MHC II?
A) TC cell
B) B cell
C) TH cell
D) Natural killer cell
E) Basophil
C) TH cell
Which of the following is not a characteristic of cellular immunity?
A) The cells originate in bone marrow.
B) Cells are processed in the thymus gland.
C) It can inhibit the immune response.
D) It includes macrophages.
E) None of the above.
D) It includes macrophages.
Which statement is incorrect?
A) The variable region of a heavy chain binds with antigen.
B) The variable region of a light chain binds with antigen.
C) The Fc region attaches to a host cell.
D) The constant region of a heavy chain is the same for all antibodies.
E) None of the above.
D) The constant region of a heavy chain is the same for all antibodies.
The best definition of an antigen is
A) Something foreign in the body.
B) A chemical that elicits an antibody response and can combine with these antibodies.
C) A chemical that combines with antibodies.
D) A pathogen.
E) A protein that combines with antibodies.
B) A chemical that elicits an antibody response and can combine with these antibodies
The best definition of an antibody is
A) A serum protein.
B) A protein that inactivates or kills an antigen.
C) A protein made in response to an antigen that can combine with that antigen.
D) An immunoglobulin.
E) None of the above.
C) A protein made in response to an antigen that can combine with that antigen.
All of the following are true about natural killer cells except
A) They destroy virus-infected cells.
B) They destroy tumor cells.
C) They destroy cells lacking MHC I.
D) They are stimulated by an antigen.
E) None of the above.
D) They are stimulated by an antigen
Antigen-antibody binding may result in all of the following except
A) Agglutination of the antigens.
B) Complement activation.
C) IL-2 production.
D) Neutralization of the antigen.
E) Opsonization of the antigen.
C) IL-2 production.
