Microbiology an Introduction: Micro Quiz 3 Flashcards

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 of these portals are used equally.

Which of the following does NOT contribute to the virulence of a pathogen?
A) Toxins
B) Cell wall
C) Numbers of microorganisms that gain access to a host
D) Enzymes
E) All of the above contribute to a pathogen's virulence

Virulence factors include all the following except
A. Capsules
B. Ribosomes
C. Exoenzymes
D. Endotoxin
E. Exotoxin

The fimbriae of Neisseria gonorrhea and enteropathogenic E. coli are examples of
A) adhesins.
B) ligands.
C) receptors.
D) adhesins and ligands.
E) adhesins, ligands, and receptors

Siderophores are bacterial proteins that compete with the host's
A) antibodies.
B) red blood cells.
C) iron-transport proteins.
D) white blood cells.
E) receptors.

Biofilms provide pathogens with an adhesion mechanism and aid int resistance to antimicrobial agent

TRUE or FALSE

Which of the following is NOT used by bacteria for attachment to a host?
A) Fimbriae

B) A-B toxin

C) Capsules

D) M protein

E) Ligands

Which of the following statements about M protein is FALSE?
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.

The antibodies found in mucus, saliva, and tears are
A) IgG.

B) IgM.

C) IgA.

D) IgD.

E) IgE.

The antibodies found on B cells are
A) IgG.

B) IgM.

C) IgA.

D) IgD.

E) IgE.

In addition to IgG, the antibodies that can fix complement are
A) IgG.

B) IgM.

C) IgA.

D) IgD.

E) IgE.

Which of the following statements about exotoxins is generally FALSE?
A) They are more potent than endotoxins.
B) They are composed of proteins.
C) They are resistant to heat.
D) They have specific methods of action.
E) They are produced by gram-positive bacteria

Antibodies produced against Exotoxins are called ____?

All of the following are used by bacteria to attach to host cells EXCEPT
A) M protein.
B) ligands.
C) fimbriae.
D) capsules.
E) A-B toxins.

Which of the following is NOT a membrane-disrupting toxin?
A) Streptolysin O
B) Streptolysin S
C) A-B toxin
D) Hemolysin
E) Leukocidin

Superantigens produce intense immune responses by stimulating lymphocytes to produce
A) endotoxins.
B) exotoxins.
C) cytokines.
D) leukocidins.
E) interferons.

Which of the following is NOT a cytopathic effect of viruses?
A) cell death
B) host cells fusing to form multinucleated syncytia
C) inclusion bodies forming in the cytoplasm or nucleus
D) increased cell growth
E) toxin production

11) 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) metabolic products

Which of the following is not a normal portal of exit of an infectious disease?
A. Removal of blood
B. Urogenital tract and feces
C. Coughing and sneezing
D. Skin
E. All of these are normal exit portals

Innate immunity
A) is slower than adaptive immunity in responding to pathogens.
B) is nonspecific and present at birth.
C) involves a memory component.
D) involves T cells and B cells.
E) provides increased susceptibility to disease.

Innate immunity is
A) The body's defense against a particular pathogen.
B) The body's ability to ward off diseases.
C) The body's defenses against any kind of pathogen.
D) The lack of resistance.
E) Increased susceptibility to disease.

Keratin is an important aspect of non-specific defense because
A. It is toxic to pathogens
B. It creates a physical barrier against pathogens
C. It destroys pathogens
D. It physically restricts pathogens to a specific region
E. None of the choices are correct

Which of the following is NOT a physical factor protecting the skin and mucous membranes from infection?
A) Tears
B) Saliva
C) Layers of cells
D) Lysozyme
E) Ciliary escalator

The most frequently used portal of entry for pathogens is the
A) Mucous membranes of the gastrointestinal tract.
B) Mucous membranes of the respiratory tract.
C) Skin.
D) Parenteral route.
E) All are used equally

Defensive cells such as T cells identify pathogens by binding which of the following?
A) Cytokines
B) Lectins
C) Complement
D) Toll-like receptors
E) Lysozyme

Which of the following statements is TRUE?
A) All three types of interferons have the same effect on the body.
B) Alpha interferon promotes phagocytosis.
C) Gamma interferon causes bactericidal activity by macrophages.
D) Alpha interferon acts against specific viruses.
E) Beta interferon attacks invading viruses.

Normal microbiota provide protection from infection in each of the following ways EXCEPT
A) they produce antibacterial chemicals.
B) they compete with pathogens for nutrients.
C) they make the chemical environment unsuitable for nonresident bacteria.
D) they produce lysozyme.
E) they change the pH of the environment.

Which of the following statements is false?
A) Kinase destroys fibrin clots.
B) Coagulase destroys blood clots.
C) Hemolysins lyse red blood cells.
D) Leukocidins destroy neutrophils.
E) Hyaluronidase breaks down substances between cells.

Which of the following exhibits the highest phagocytic activity?
A) Neutrophils
B) Erythrocytes
C) Eosinophils
D) Basophils
E) Lymphocytes

The chemical mediators of anaphylaxis are
A) Antibodies.
B) Antigen-antibody complexes.
C) Antigens.
D) The proteins of the complement system.
E) Found in basophils and mast cells.

Which of the following is involved in resistance to parasitic helminths?
A) basophils
B) eosinophils
C) lymphocytes
D) monocytes
E) neutrophils

Which white blood cells comprise 3-7% of circulating WBC's, are phagocytic and can migrate out into
body tissues to differentiate into macrophages?
A. Basophils
B. Eosinophils
C. Neutrophils
D. Monocytes
E. Lymphocytes

Which of the following is NOT an effect of histamine?
A) Fever
B) Pain
C) Swelling
D) Vasodilation
E) Redness

Which one of the following is NOT an effect of fever?
A) Increases transferrin production.
B) Kills pathogens.
C) Increases interleukin-1.
D) Increases alpha interferon activity.
E) Increases production of T cells.

Several inherited deficiencies in the complement system occur in humans. Which of the
following would be the MOST severe?
A) deficiency of C3
B) deficiency of C5
C) deficiency of C6
D) deficiency of C7
E) deficiency of C8

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

What type of immunity results 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

What type of immunity results 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

Which of the following is the best definition of epitope?
A) specific regions on antigens that interact with T-cell receptors
B) specific regions on antigens that interact with MHC class molecules
C) specific regions on antigens that interact with haptens
D) specific regions on antigens that interact with antibodies
E) specific regions on antigens that interact with perforins

Newborns' immunity due to the transfer of antibodies across the placenta is an example of
A) innate immunity.
B) naturally acquired active immunity.
C) naturally acquired passive immunity.
D) artificially acquired active immunity.
E) artificially acquired passive immunity.

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

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

15) The antibodies found in mucus, saliva, and tears are
A) IgG.
B) IgM.
C) IgA.
D) IgD.
E) IgE

The most abundant class of antibodies in serum is
A) IgG.
B) IgM.
C) IgA.
D) IgD.
E) IgE.

Which of the following is the best definition of antigen?
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

Which of the following is an effect of opsonization?
A) Cytolysis
B) Increased diapedesis of phagocytes
C) Increased margination of phagocytes
D) Inflammation
E) Increased adherence of phagocytes to microorganisms

A reaction between antibody and particulate antigen is called a(n)
A) Agglutination reaction.
B) Neutralization reaction.
C) Immunofluorescence.
D) Precipitation reaction.
E) Complement fixation.

Helper T cells
A. secrete antibodies.
B. function in allergic reactions.
C. directly destroy target cells.
D. suppress immune reactions.
E. activate B cells and other T cells.

Cytotoxic T cells
A. stimulate B cell proliferation.
B. lack specificity for a target cell.
C. secrete granzymes and perforins that damage target cells.
D. secrete interleukin-2 to stimulate B and T cells.
E. All of the choices are correct.

Which are the first to attack cancer cells and virus-infected cells?
A. helper T cells
B. suppressor T cells
C. cytotoxic T cells
D. delayed hypersensitivity T cells
E. natural killer (NK) cells

An example of artificial passive immunity would be
A. chickenpox infection is followed by lifelong immunity.
B. chickenpox vaccine triggers extended immunity to chickenpox.
C. giving a person immune serum globulins to chickenpox virus after exposure to the disease.
D. a fetus acquiring maternal IgG to the chickenpox virus across the placenta.
E. None of the choices are correct.

Hemolytic disease of the newborn can result from an
A) Rh+ mother with an Rh- fetus.
B) Rh- mother with an Rh+ fetus.
C) AB mother with a B fetus.
D) AB mother with an O fetus.
E) Rh- mother and an A fetus

All of the following are examples of autoimmune diseases, except
A. multiple sclerosis.
B. Graves disease.
C. Hashimoto thyroiditis.
D. myasthenia gravis.
E. Wiskott-Aldrich syndrome.

Attachment of HIV to the target cell depends on
A) gp120 combining with the CD4+ receptor.
B) gp120 combining with the chemokine receptor CCR5.
C) gp41 binding to the CD4+ receptor.
D) gp120 binding to the CD4+ plasma membrane.
E) CXCR4 binding to the CD4+ receptor.

Treatment with certain drugs to reduce transplant rejection can cause
A) Immunologic surveillance.
B) Immunosuppression.
C) Immunotherapy.
D) Autoimmunity
E) Immunologic enhancement.

Septic shock due to gram-positive bacteria is caused by
A) Lipid A.
B) A-B toxins.
C) Membrane-disrupting toxins.
D) Erythrogenic toxin.
E) Superantigens.

Hypersensitivity is due to
A) Allergies.
B) Immunity.
C) The presence of an antigen.
D) The presence of antibodies.
E) An altered immune response.

Which of the following statements about type I hypersensitivities is false?
A) They are cell-mediated.
B) Antibodies are bound to host cells.
C) They involve IgE antibodies.
D) The symptoms occur soon after exposure to an antigen.
E) The symptoms are due to histamine.

Which of the following statements about type IV hypersensitivities is false?
A) They are cell-mediated.
B) The symptoms occur within a few days after exposure to an antigen.
C) The symptoms are due to lymphokines.
D) They contribute to the symptoms of certain diseases.
E) They can be passively transferred with serum.

Which of the following is NOT considered a type I hypersensitivity?
A) Pollen allergies
B) Asthma
C) Dust allergies
D) Penicillin allergic reactions
E) Transplant rejections

Which of the following statements about type IV reactions is FALSE?
A) Reactions are primarily due to T cell proliferation.
B) Reactions are not apparent for a day or more.
C) Cytokines initiate tissue damage.
D) Allergic contact dermatitis is an example.
E) Hemolytic disease of the newborn is an example.

The major categories of hypersensitivities that typically involve a B-cell immunoglobulin response is/
are
A. Type 1 only.
B. Type 1 and Type 4.
C. Type 4 only.
D. Type 1, Type 2, Type 3.
E. Type 1, Type 2, Type 3, and Type 4.

Atopy and anaphylaxis are hypersensitivities in the category
A. Type 1 only.
B. Type 1 and Type 4.
C. Type 4 only.
D. Type 1, Type 2, Type 3.
E. Type 1, Type 2, Type 3, and Type 4.

All of the following are involved in Type 2 hypersensitivity, except
A. IgM.
B. IgG.
C. IgE.
D. complement.
E. foreign cells.

Which is mismatched?
A. Food allergy - Type I hypersensitivity
B. Poison ivy dermatitis - Type 4 hypersensitivity
C. Serum sickness - Type 3 hypersensitivity
D. Transfusion reaction - Type 2 hypersensitivity
E. Hay fever - Type 4 hypersensitivity

Viruses that have reverse transcriptase are in the
A) Bacteriophage families.
B) Retroviridae and Picornaviridae.
C) Influenzavirus.
D) Hepadnaviridae and Retroviridae.
E) Herpesviridae and Retroviridae.

Which of the following may be inherited or result from HIV infection?
A) Immunosuppression
B) Immunologic enhancement
C) Immunotherapy
D) Immunologic surveillance
E) Autoimmunity

Which of the following is the LEAST likely vaccine against HIV?
A) Protein core
B) Glycoprotein
C) Subunit
D) Attenuated virus
E) All of the above are equally likely.

What material in skin cells provides protection from abrasions, water damage and microorganism entry?
A. Lysozyme
B. Keratin
C. Sweat
D. Sebum
E. Salt

The patient has vesicles and scabs over her forehead. Microscopic examination of skin scrapings shows gram-positive cocci in clusters. The etiology is
A) Candida.
B) Microsporum.
C) Pseudomonas aeruginosa.
D) Staphylococcus aureus.
E) Sarcoptes.

What group of microorganisms do not usually call the skin "home"?
A. Micrococci
B. Diphtheroids
C. Spirochetes
D. Yeasts
E. All the choices are correct

The causative agent of acne is
A. Staphylococcus aureus
B. Micrococcus luteus
C. Propionibacterium acnes
D. Streptococcus epidermidis
E. Corynebacterium diphtheriae

Which of the following is not true of Propionibacterium acnes?
A. Anaerobic or aerotolerant
B. Gram-negative rod
C. Releases lipase
D. Attracts white blood cells
E. Present in hair follicles

Propionibacterium acnes is normal flora of sebaceous glands of the skin.
True or False

An eight-year-old girl has scabs and pus-filled vesicles on her face and throat. Three weeks
earlier she had visited her grandmother, who had shingles. What infection does the eight-yearold
have?
A) chickenpox
B) measles
C) fever blisters
D) scabies
E) rubella

Which microorganism species is most well adapted to life on the skin?
A. S. aureus
B. C. diphtheriae
C. S. epidermidis
D. Malassezia
E. Candida albicans

Impetigo is caused by
A. P. acnes
B. C. diphtheriae
C. S. aureus
D. S. pyogenes
E. Both S. aureus and S. pyogenes

All Staphylococci can be differentiated from all Streptococci because only Staphylococci produce the
enzyme _____ that is easily detected in the lab.
A. Staphlokinase
B. Exfoliative toxin A
C. Exfoliative toxin B
D. Catalase
E. Lactase

The majority of the staphylococci isolated from human skin are coagulase-positive.
true or false

Blue-green pus is characteristic of Pseudomonas wound infections.

true or false

Warts are caused by
A) papillomavirus.
B) poxvirus.
C) herpesvirus.
D) parvovirus.
E) Staphylococcus aureus.

The normal flora of the skin is predominantly gram-negative rods.
true or false

Impetigo is caused by
A. P. acnes
B. C. diphtheriae
C. S. aureus
D. S. pyogenes
E. Both S. aureus and S. pyogenes

Which is true of viral conjunctivitis?
A. Caused by Chlamydia trachomatis or Neisseria gonorrhoeae
B. Has a mucopurulent discharge
C. Caused by adenoviruses
D. Must be treated with topical and oral antibiotics
E. Caused by Moraxella

Newborns' eyes are treated with an antibiotic
A) when Neisseria gonorrhoeae is isolated from the eyes.
B) when the mother is blind.
C) when the mother has genital herpes.
D) when the mother has gonorrhea.
E) as a routine precaution.

What eye disease is characterized by pannus forming over the cornea?
A. Simple conjunctivitis
B. Keratitis
C. Sty
D. Trachoma
E. River blindness

Which of the following can be treated with topical chemotherapeutic agents?
A) Dermatomycosis
B) Sporotrichosis
C) Rubella
D) Shingles
E) Herpes gladiatorium

Which of the following pairs is mismatched?
A) Infected tissue fluoresces = Dermatomycosis
B) Conjunctivitis =Chlamydia trachomatis
C) Buruli ulcer= Mycobacterium
D) Chickenpox =Poxvirus
E) Keratitis= Acanthamoeba