World's Toughest Trivia Quiz On Microbiology!

229 Questions

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Microbiology Quizzes & Trivia

How good are you when it comes to knowledge on microbiology? The quiz below is considered the toughest trivia and is designed to sieve out the best out of all the top students in the class. Do you think that you can take it up and see if you are among the top students in the class? Well, do give it a shot and see how good you will do.


Questions and Answers
  • 1. 
    Which type of infection can be caused by septicemia?
    • A. 

      Systemic infection

    • B. 

      Focal infection

    • C. 

      Local infection

    • D. 

      Bacteremia

    • E. 

      Septicemia

  • 2. 
    Transient microbiota differ from normal microbiota because transient microbiota
    • A. 

      Are present for a relatively short time

    • B. 

      Cause diseases

    • C. 

      Are found in a certain location on the host

    • D. 

      Are acquired by direct contact

    • E. 

      None of the above

  • 3. 
    Which of the following definitions is incorrect?
    • A. 

      Pandemic - a disease that affects a large number of people in the world in a short time

    • B. 

      Endemic - a disease that is constantly present in a population

    • C. 

      Epidemic - a fraction of the population having a disease at a specified time

    • D. 

      Sporadic - a disease that affects a population occasionally

    • E. 

      None of the above

  • 4. 
    Which of the following is a fomite?
    • A. 

      Insects

    • B. 

      Droplets from a sneeze

    • C. 

      Water

    • D. 

      A hypodermic needle

    • E. 

      Pus

  • 5. 
    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

  • 6. 
    A nosocomial infection is
    • A. 

      Only a result of surgery

    • B. 

      Acquired during the course of hospitalization

    • C. 

      always present but inapparent at the time of hospitalization

    • D. 

      Always caused by medical personnel

    • E. 

      Always caused by pathogenic bacteria

  • 7. 
    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 are the result of disease.

    • E. 

      Microorganisms cause disease.

  • 8. 
    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

  • 9. 
    Symptoms of disease differ from signs of disease in that symptoms
    • A. 

      Always occur as part of a syndrome

    • B. 

      Are changes felt by the patient

    • C. 

      Are changes observed by the physician

    • D. 

      Are specific for a particular disease

    • E. 

      None of the above

  • 10. 
    All of the following are communicable diseases except
    • A. 

      Tyhphoid fever

    • B. 

      Tuberculosis

    • C. 

      Tetanus

    • D. 

      Malaria

    • E. 

      AIDS

  • 11. 
    Which of the following does NOT contribute to a pathogen's invasiveness?
    • A. 

      Cell wall

    • B. 

      Capsule

    • C. 

      Toxins

    • D. 

      Ligands

    • E. 

      Hyaluronidase

  • 12. 
    A needlestick is an example of which portal of entry?
    • A. 

      Skin

    • B. 

      Paranaternal route

    • C. 

      Mucous membranes

    • D. 

      All of the above

    • E. 

      None of the above

  • 13. 
    All of the following are types of exotoxins EXCEPT
    • A. 

      Lipid A

    • B. 

      Membrane disrupting toxins

    • C. 

      AB toxins

    • D. 

      Superantigens

    • E. 

      All of the above are types of exotoxins

  • 14. 
    Which of the following statements about exotoxins is generally NOT true?
    • A. 

      They are composed of proteins

    • B. 

      They are not required in high concentrations to be effective

    • C. 

      They are not destroyed by heat

    • D. 

      They have specific methods of action

    • E. 

      They are more potent than endotoxins

  • 15. 
    Cytopathic effects are changes in host cells due to
    • A. 

      Viral infections

    • B. 

      Protozoan and helminthic infections

    • C. 

      Bacterial infections

    • D. 

      Fungal infections

    • E. 

      All of the above

  • 16. 
    All of the following are methods of penetrating and/or avoiding the host EXCEPT
    • A. 

      Antigenic changes

    • B. 

      Membrane-disrupting toxins

    • C. 

      Hyaluronidase

    • D. 

      IgA proteases

    • E. 

      Invasins

  • 17. 
    Siderophores are bacterial proteins that compete with animal
    • A. 

      White blood cells

    • B. 

      Transferrins

    • C. 

      Antibodies

    • D. 

      Red blood cells

    • E. 

      Ferrodoxins

  • 18. 
    Endotoxins are
    • A. 

      Required only in minute amounts

    • B. 

      Excreted from the cell

    • C. 

      Associated with Gram-positive bacteria

    • D. 

      Specific in their mode of action

    • E. 

      Part of the Gram-negative cell wall

  • 19. 
    The most frequently used portal of entry for pathogens is the
    • A. 

      Mucous membranes of the respiratory tract

    • B. 

      Mucous membranes of the genitourinary tract.

    • C. 

      Skin

    • D. 

      Parenteral route

    • E. 

      All of the above

  • 20. 
    Botulism is caused by an exotoxin, therefore it could be easily prevented by
    • A. 

      Administering antibiotics to patients.

    • B. 

      Boiling food prior to consumption

    • C. 

      Including antibiotics in the canning process

    • D. 

      Preventing fecal contamination of food

    • E. 

      Just not eating canned food

  • 21. 
    Which of the following is involved in specific resistance (immunity)?
    • A. 

      Monocyte

    • B. 

      Basophil

    • C. 

      Neutrophil

    • D. 

      Lymphocyte

    • E. 

      Eosinophil

  • 22. 
    All of the following are associated with complement fixation EXCEPT
    • A. 

      Inflammation

    • B. 

      Cell lysis

    • C. 

      Membrane attack complex

    • D. 

      Increased phagocytic activity

    • E. 

      Fever

  • 23. 
    Which of the following is involved in fighting parasitic infections?
    • A. 

      Eosinophil

    • B. 

      Basophil

    • C. 

      Lymphocyte

    • D. 

      Neutrophil

    • E. 

      Monocyte

  • 24. 
    All of the following occur during inflammation.  What is the first step?
    • A. 

      Vasodilation

    • B. 

      Diapedesis

    • C. 

      Repair

    • D. 

      Phagocyte migration

    • E. 

      Margination

  • 25. 
    Which of the following is NOT a characteristic of inflammation?
    • A. 

      Fever

    • B. 

      Local heat

    • C. 

      Pain

    • D. 

      Swelling

    • E. 

      Redness

  • 26. 
    Which of the following exhibits the highest phagocytic activity?
    • A. 

      Erythrocytes

    • B. 

      Eosinophils

    • C. 

      Lymphocytes

    • D. 

      Neutrophils

    • E. 

      Basophils

  • 27. 
    Which of the following is NOT a chemical factor to protect the skin and mucous membranes from infection?
    • A. 

      Gastric juices

    • B. 

      Ciliary escalator

    • C. 

      Lysozyme

    • D. 

      Mucus

    • E. 

      Sebum

  • 28. 
    Macrophages arise from which of the following?
    • A. 

      Neutrophil

    • B. 

      Lymphocyte

    • C. 

      Monocyte

    • D. 

      Eosinophil

    • E. 

      Basophil

  • 29. 
    Nonspecific resistance is
    • A. 

      The body's ability to ward off diseases.

    • B. 

      The body's defenses against any kind of pathogen

    • C. 

      The body's defenses against a specific pathogen

    • D. 

      The lack of resistance

    • E. 

      None of the above

  • 30. 
    Bacteria have siderophores to capture iron; humans counter this by
    • A. 

      Producing iron

    • B. 

      Producing sulfur dioxide

    • C. 

      Transferrins

    • D. 

      Iron-degrading enzymes

    • E. 

      Toxin production

  • 31. 
    In which organism were phagocytes first reported?
    • A. 

      Bacteria

    • B. 

      Amoeba

    • C. 

      Red blood cells

    • D. 

      Starfish larvae

  • 32. 
    Which is not a component of innate immunity?
    • A. 

      Skin

    • B. 

      Inflammation

    • C. 

      Fever

    • D. 

      Antibody

  • 33. 
    Which of the following is a phagocytic cell found in the human body?
    • A. 

      Erythrocyte

    • B. 

      Neutrophil

    • C. 

      B cell

    • D. 

      T cell

  • 34. 
    The leukocyte described as having a small amount of cytpolasm surrounding a round nucleus is the
    • A. 

      Lymphocyte

    • B. 

      Monocyte

    • C. 

      Basophil

    • D. 

      Neutrophil

  • 35. 
    Skin and mucous membranes
    • A. 

      Are the first line of innate immunity

    • B. 

      Are the first line of adaptive immunity

    • C. 

      Act as physical barriers to infection

    • D. 

      Contain antimicrobial secretions

    • E. 

      A, c and d

  • 36. 
    A group of interacting serum proteins that provide a nonspecific defense mechanism is
    • A. 

      Complement

    • B. 

      Interferon

    • C. 

      Glycoprotein

    • D. 

      Lysozome

  • 37. 
    The first host response to a nonspecific tissue injury is described as
    • A. 

      Inflammation

    • B. 

      Reaction

    • C. 

      Antibodies

    • D. 

      Trauma

  • 38. 
    Following digestion of a microorganism by phagocytes, the debris is excreted by
    • A. 

      Ingestion

    • B. 

      Exocytosis

    • C. 

      Extrusion

    • D. 

      Budding

  • 39. 
    Which of the following cytokines is most antiviral in its action?
    • A. 

      Interleukin-1 (IL-1)

    • B. 

      Interleukin-2 (IL-2)

    • C. 

      Interferon

    • D. 

      Lysozyme

  • 40. 
    Pyrogens are
    • A. 

      Fever-inducing substances

    • B. 

      Fever-inhibiting substances

    • C. 

      Phagocytosis-enhancing substances

    • D. 

      Complement activators

  • 41. 
    The hypersensitivity treatment that stimulates an increase of IgG and T suppressor cells, and a decrease in IgE is known as
    • A. 

      Desensitization

    • B. 

      Immunity

    • C. 

      Sensitization

    • D. 

      Exposure

    • E. 

      Anaphylaxis

  • 42. 
    A transfusion reaction primarily involves
    • A. 

      Leukocytes

    • B. 

      Phagocytes

    • C. 

      Platelets

    • D. 

      Erythrocytes

  • 43. 
    Regarding a mismatch of either the Rh antigen or the AB antigen both
    • A. 

      Result in destruction of red blood cells

    • B. 

      Utilize complement to destroy red blood cells

    • C. 

      Utilize antibody-dependent cellular cytotoxicity to destroy the red blood cells

    • D. 

      Result in destruction of only leukocytes

  • 44. 
    Antibodies that have arisen in the blood plasma without any obvious or deliberate stimulus are called
    • A. 

      Natural

    • B. 

      Acquired

    • C. 

      Injurious

    • D. 

      Active

  • 45. 
    The cell type responsible for Type II hypersensitivity is the
    • A. 

      Mast cell

    • B. 

      B cell

    • C. 

      Macrophage

    • D. 

      Platelet

    • E. 

      Neutrophils

  • 46. 
    Delayed type hypersensitivity primarily involves
    • A. 

      Erythrocytes

    • B. 

      B cells

    • C. 

      T cells

    • D. 

      Mast cells

  • 47. 
    Type IV hypersensitivity reactions typically peak within
    • A. 

      Minutes

    • B. 

      Hours

    • C. 

      12 hours

    • D. 

      2-3 days

  • 48. 
    Which of the following is associated with contact dermatitis?
    • A. 

      Poison ivy

    • B. 

      Latex

    • C. 

      Tuberculin skin test

    • D. 

      Hay fever

    • E. 

      A, b and c

  • 49. 
    Allografts
    • A. 

      Are normally rejected within hours

    • B. 

      Are normally rejected within 10-14 days

    • C. 

      Are grafts between non-identical members of the same species

    • D. 

      Would include the fetus

    • E. 

      B, c and d

  • 50. 
    If the thymus fails to develop,
    • A. 

      Functional T cells are absent

    • B. 

      Functional B cells are absent

    • C. 

      Di George's syndrome exists

    • D. 

      Complement deficiencies exist

    • E. 

      A and c

  • 51. 
    Which of the following is not a granulocyte?
    • A. 

      Eosinophil

    • B. 

      Macrophage

    • C. 

      Basophil

    • D. 

      Neutrophil

  • 52. 
    The leukocyte that contains histamine is the
    • A. 

      Lymphocyte

    • B. 

      Monocyte

    • C. 

      Macrophage

    • D. 

      Basophil

  • 53. 
    In humans, the stem cells from which all blood cells arise are found in the
    • A. 

      Peripheral circulation

    • B. 

      Lymphatic vessels

    • C. 

      Lymph nodes

    • D. 

      Bone marrow

  • 54. 
    Allergic reactions mainly involve
    • A. 

      Macrophages

    • B. 

      Monocytes

    • C. 

      Neutrophils

    • D. 

      Mast cells

  • 55. 
    Which of the following is a phagocytic cell found in the human body?
    • A. 

      Erythrocyte

    • B. 

      Neutrophil

    • C. 

      B cell

    • D. 

      T cell

  • 56. 
    Which of the following are referred to as mononuclear phagocytes?
    • A. 

      Lymphocytes and basophils

    • B. 

      Mast cells and eosinophils

    • C. 

      Basophils and eosinophils

    • D. 

      Monocytes and macrophages

  • 57. 
    Which of the following are antigen-presenting cells?
    • A. 

      Dendritic cells

    • B. 

      T cells

    • C. 

      Erythrocytes

    • D. 

      Basophils

  • 58. 
    The leukocyte responsible for adaptive immunity is the
    • A. 

      Lymphocyte

    • B. 

      Monocyte

    • C. 

      Eosinophil

    • D. 

      Neutrophil

  • 59. 
    The "voices" of a cell are
    • A. 

      Surface receptors

    • B. 

      Platelets

    • C. 

      Cytokines

    • D. 

      Antigens

  • 60. 
    Normal flora
    • A. 

      Are the organisms that typically reside on your body

    • B. 

      Protect against infection by pathogens

    • C. 

      Enhance infection by pathogens

    • D. 

      Play no role in affecting pathogen growth

    • E. 

      A and b

  • 61. 
    The first step in the establishment of infection is that the organism must
    • A. 

      Invade host tissues

    • B. 

      Attach to host cells

    • C. 

      Evade phaogcytes

    • D. 

      Produce toxins

  • 62. 
    The complex resulting from complement activity that leads to cell lysis is the
    • A. 

      Prostaglandin complex

    • B. 

      Leukotriene activating complex

    • C. 

      Membrane attack complex

    • D. 

      Histamine complex

  • 63. 
    Diseases that can be transmitted from one person to another are termed
    • A. 

      Symptomatic

    • B. 

      Clinical

    • C. 

      Acute

    • D. 

      Latent

    • E. 

      Communicable

  • 64. 
    Opportunists or opportunistic pathogens
    • A. 

      Are usually saprophytes

    • B. 

      Take advantage of special circumstances

    • C. 

      Are usually mutalistic

    • D. 

      Always cause disease

  • 65. 
    A relationship in which one partner benefits and the other is unaffected is termed
    • A. 

      Commensalism

    • B. 

      Parasitism

    • C. 

      Independence

    • D. 

      Mutualism

  • 66. 
    All of the following are involved in Type II hypersensitivity except
    • A. 

      IgM

    • B. 

      IgG

    • C. 

      IgE

    • D. 

      Complement

    • E. 

      Foreign cells

  • 67. 
    The humoral immune response involves the manufacture and use of 
    • A. 

      Antibodies

    • B. 

      T cells

    • C. 

      Lymphokines

    • D. 

      Antigens

  • 68. 
    A person with O type blood
    • A. 

      Lacks all the alleles for ABO blood type

    • B. 

      Lacks A and B antigens

    • C. 

      Could not have the Rh factor

    • D. 

      Is called a universal recipient

    • E. 

      All of the choices are correct

  • 69. 
    The complement pathway that requires antibodies to be activated is the
    • A. 

      Alternate pathway

    • B. 

      Classical pathway

    • C. 

      Properdin pathway

    • D. 

      Inflammatory pathway

  • 70. 
    The microorganisms that are regularly found in or on the body, yet do no apparent  harm are called
    • A. 

      Abnormal flora

    • B. 

      Transient flora

    • C. 

      Variant flora

    • D. 

      Normal flora

  • 71. 
    The potential for hemolytic disease of the newborn occurs when
    • A. 

      Maternal Rh+ cells enter an Rh- fetus

    • B. 

      Fetal Rh+ cells enter an Rh- mother

    • C. 

      Maternal Rh- cells enter an Rh+ fetus

    • D. 

      Fetal Rh- cells enter an Rh+ mother

    • E. 

      Fetal Rh+ cells enter an Rh+ mother

  • 72. 
    T cells and B cells are manufactured in the
    • A. 

      Bone marrow

    • B. 

      Thymus

    • C. 

      Peyer's Patches

    • D. 

      Nervous tissue

  • 73. 
    Which of the following is a phagocytic cell found in the human body?
    • A. 

      Erythrocyte

    • B. 

      Neutrophil

    • C. 

      B cell

    • D. 

      T cell

  • 74. 
    An epidemic that spreads worldwide is called a(n)
    • A. 

      Epidemical

    • B. 

      Endemic

    • C. 

      Pandemic

    • D. 

      Syndemic

  • 75. 
    Allergic reactions mainly involve
    • A. 

      Macrophages

    • B. 

      Monocytes

    • C. 

      Neutrophils

    • D. 

      Mast cells

  • 76. 
    Which process involves antibodies coating microorganisms in order to facilitate phagocytosis?
    • A. 

      Neutralization

    • B. 

      Opsonization

    • C. 

      Complement fixation

    • D. 

      Agllutination

    • E. 

      Anamnestic response

  • 77. 
    MHC molecules are found on each of the following cells except
    • A. 

      Leukocytes

    • B. 

      Eosinophils

    • C. 

      Epithelial cells

    • D. 

      Red blood cells

    • E. 

      Islet of langerhans cells

  • 78. 
    Delayed type hypersensitivity primarily involves
    • A. 

      Erythrocytes

    • B. 

      B Cells

    • C. 

      T cells

    • D. 

      Mast cells

  • 79. 
    Organisms that are found together and interact on a more or less permanent basis are in a relationship termed
    • A. 

      Mutualism

    • B. 

      Parasitism

    • C. 

      Symbiosis

    • D. 

      Commensalism

  • 80. 
    Interferons function to make cells
    • A. 

      Resistant to viral replication

    • B. 

      Lyse when exposed to virus

    • C. 

      Non-motile when infected with virus

    • D. 

      Resistant to phagocytosis

  • 81. 
    The major categories of hypersensitivities that typically involve a B-cell immunoglobulin response is/are
    • A. 

      Type I only

    • B. 

      Type I and Type IV

    • C. 

      Type IV only

    • D. 

      Type I, Type II, Type III

    • E. 

      Type I, Type II, Type III, and Type IV

  • 82. 
    T cells primarily are responsible for
    • A. 

      Humoral immunity

    • B. 

      Cell-mediated immunity

    • C. 

      Anamnestic immunity

    • D. 

      Producing haptens

  • 83. 
    The series of steps used to connect an organism to a disease are known as
    • A. 

      Pasteur's postulates

    • B. 

      Lister's aseptics

    • C. 

      Linnaeus taxonomics

    • D. 

      Koch's postulates

  • 84. 
    Macrophages and dendritic cells are
    • A. 

      T cells

    • B. 

      B cells

    • C. 

      Antigen-presenting cells

    • D. 

      Antibody-presenting cells

  • 85. 
    A disease-causing microorganism or virus is referred to as a(n)
    • A. 

      Avirulent infection

    • B. 

      Colony

    • C. 

      Commensal

    • D. 

      Pathogen

  • 86. 
    Which is not a component of innate immunity?
    • A. 

      Skin

    • B. 

      Inflammation

    • C. 

      Fever

    • D. 

      Antibody

  • 87. 
    Which process involves antibodies covering surface receptors on a virus or toxin molecule thereby disrupting their activity?
    • A. 

      Neutralization

    • B. 

      Opsonization

    • C. 

      Complement fixation

    • D. 

      Agglutination

    • E. 

      Anamnestic response

  • 88. 
    An infection acquired during hospitalization is reffered to as
    • A. 

      Antibiotic-induced

    • B. 

      Therapeutic

    • C. 

      Medication-stimulated

    • D. 

      Nosocomial

  • 89. 
    Inanimate objects capable of transferring infectious disease agents are
    • A. 

      Vectors

    • B. 

      Fomites

    • C. 

      Vehicles

    • D. 

      Reservoirs

  • 90. 
    The leukocyte responsible for adaptive immunity is the
    • A. 

      Lymphocyte

    • B. 

      Monocyte

    • C. 

      Eosinophil

    • D. 

      Neutrophil

  • 91. 
    Diseases that cause long-term or permanent damage leave
    • A. 

      Latent

    • B. 

      Sequelae

    • C. 

      Directly

    • D. 

      Indirectly

    • E. 

      Chronically

  • 92. 
    A __________ is an infection indigenous to animals that can, on occasion, be transmitted to humans
    • A. 

      Secondary infection

    • B. 

      Sequelae

    • C. 

      Nosocomial infection

    • D. 

      Zoonosis

    • E. 

      None of the choices are correct

  • 93. 
    The body region where a ciliary escalator helps to sweep microbes trapped in mucus away from that body site is the
    • A. 

      Skin

    • B. 

      Respiratory tract

    • C. 

      Digestive tract

    • D. 

      Urinary tract

    • E. 

      Eyes

  • 94. 
    Which is mismatched?
    • A. 

      Fibriae - adherence to substrate

    • B. 

      Capsultes - antiphagocytic factor

    • C. 

      Coagulase - dissolve fibrin clots

    • D. 

      Leukocidins - damage white blood cells

    • E. 

      Hemolysins - damage red blood cells

  • 95. 
    A symptom is a(n)
    • A. 

      Objective indication of disease

    • B. 

      Subjective indication of disease

    • C. 

      Measurable by health care personnel

    • D. 

      Temperature

    • E. 

      None of the choices are correct

  • 96. 
    Which event is the process of releasing chemical mediators?
    • A. 

      Degranulation

    • B. 

      Bonding of allergen to adjacent IgE binding sites on mast cells and basophils

    • C. 

      Binding of IgE by the Fc region to mast cells and basophils

    • D. 

      Histamine acts on smooth muscle

    • E. 

      Prostaglandins cause vasodilation and increased vascular permeability

  • 97. 
    Nosocomial infections involve all the following except:
    • A. 

      Are only transmitted by medical personnel

    • B. 

      Often involve the patient's urinary tract and surgical incisions

    • C. 

      The patient's resident biota can be the infectious agent

    • D. 

      Escherichia coli and staphylococci are common infectious agents

    • E. 

      Medical and surgical asepsis help lower their occurrence

  • 98. 
    Pathogenic microbes that cause disease in healthy people are called
    • A. 

      Opportunistic pathogens

    • B. 

      Normal biota

    • C. 

      Indigenous biota

    • D. 

      True pathogens

    • E. 

      Micropathogens

  • 99. 
    When an individual's immune system comes into contact with an appropriate antigenic stimulus during the course of daily activities, this is called
    • A. 

      Naturally acquired passive immunity

    • B. 

      Naturally acquired active immunity

    • C. 

      Artificially acquired active immunity

    • D. 

      Artificially acquired passive immunity

  • 100. 
    Under normal circumstances, the microbiota of the skin is kept in check by
    • A. 

      A high pH (>8)

    • B. 

      A slightly acidic pH

    • C. 

      Phagocytic activity

    • D. 

      Excessive moisture

  • 101. 
    All blood cells originate from the
    • A. 

      Erythrocyte

    • B. 

      Leukocytic stem cell

    • C. 

      Eosinophilic stem cell

    • D. 

      Hematopoietic stem cell

  • 102. 
    The initial encounter with an allergen is called the
    • A. 

      Sensitizing dose

    • B. 

      Provocative dose

    • C. 

      Allergic dose

    • D. 

      Hypersensitivity dose

    • E. 

      Densensitizing dose

  • 103. 
    __________ carriers are shedding and transmitting pathogen while they are recovering from an infectious disease.
    • A. 

      Asymptomatic

    • B. 

      Passive

    • C. 

      Incubation

    • D. 

      Chronic

    • E. 

      Convalescent

  • 104. 
    Each of the following are physical barriers to pathogens except
    • A. 

      Unbroken skin

    • B. 

      Mucous

    • C. 

      Hairs

    • D. 

      Tears

    • E. 

      T Cells

  • 105. 
    Which of the following is the endotoxin?
    • A. 

      Hemolysin

    • B. 

      Hyaluronidase

    • C. 

      Toxinosis

    • D. 

      Collagenase

    • E. 

      Lipopolysaccharide

  • 106. 
    The transfer of antibodies in colostrum is a good example of
    • A. 

      Naturally acquired passive immunity

    • B. 

      Naturally acquired active immunity

    • C. 

      Artificially acquired active immunity

    • D. 

      Artificially acquired passive immunity

  • 107. 
    In multiple sclerosis, autoantibodies attack
    • A. 

      Myelin sheath cells of the nervous system

    • B. 

      Acetylcholine receptors on smooth muscle

    • C. 

      Acetylcholine receptors on skeletal muscle

    • D. 

      Sodium pump proteins in the cell membrane

    • E. 

      Cells in thyroid follicles

  • 108. 
    Substances that are recognized as foriegn and provoke immune responses are called
    • A. 

      Antibodies

    • B. 

      Antigens

    • C. 

      Infective agents

    • D. 

      Inducers

  • 109. 
    Exotoxins
    • A. 

      Are secreted by pathogenic organisms

    • B. 

      Are bound to the membrane of pathogenic organisms

    • C. 

      Are bound to the cell wall of pathogenic organisms

    • D. 

      Cause more damage than endotoxins

    • E. 

      Are host specific

  • 110. 
    The complement pathway that is activated by mannan binding lectins is the 
    • A. 

      Classical pathway

    • B. 

      Alternate pathway

    • C. 

      C3 pathway

    • D. 

      Lectin pathway

  • 111. 
    A properly functioning immune system is responsible for
    • A. 

      Surveillance of the body

    • B. 

      Recognition of foreign material

    • C. 

      Destruction of foreign material

    • D. 

      B and C

    • E. 

      A, B, and C

  • 112. 
    Each of the following are inoculation of normal biota to a newborn except
    • A. 

      The birth process through the birth canal

    • B. 

      Bottle feeding

    • C. 

      Breast feeding

    • D. 

      Contact with hospital staff

    • E. 

      All of the choices are correct

  • 113. 
    Which type of hypersensitivity is IgE?
    • A. 

      Type IV

    • B. 

      Type III

    • C. 

      Type II

    • D. 

      Type I

  • 114. 
    All the following are events of early inflammation except
    • A. 

      Macrophages appear first and begin phagocytosis

    • B. 

      Chemical mediators and cytokines are released

    • C. 

      Brief vasoconstriction is followed by vasodilation

    • D. 

      Exudate and pus can accumulate

    • E. 

      Capillaries become more permeable resulting in edema

  • 115. 
    Which of the following is not an event of phagocytosis?
    • A. 

      Diapedesis

    • B. 

      Chemotaxis

    • C. 

      Phagolysosome formation

    • D. 

      Destruction

    • E. 

      Ingestion

  • 116. 
    Autoantibodies cause tissue injury in all the following diseases except
    • A. 

      Rheumatoid arthritis

    • B. 

      Myasthenia gravis

    • C. 

      Graves' disease

    • D. 

      Tuberculin reaction

    • E. 

      Multiple Sclerosis

  • 117. 
    A systemic, sometimes fatal reaction with airway obstruction and circulatory collapse is
    • A. 

      Delayed

    • B. 

      T cell mediated

    • C. 

      Atopic

    • D. 

      Antibody-mediated

    • E. 

      Anaphylaxis

  • 118. 
    Each of the following can result in acquired immune deficiencies except
    • A. 

      Malnutrition

    • B. 

      Stress

    • C. 

      Pregnancy

    • D. 

      Bacterial infection

    • E. 

      Radiation treatment

  • 119. 
    Which lymphocytes lack specificity for antigen and are cells that 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

  • 120. 
    Fever
    • A. 

      Enhances bacterial growth

    • B. 

      Inhibits bacterial growth

    • C. 

      Speeds up the body's reactions

    • D. 

      Triggers complement

    • E. 

      Inhibits bacterial growth AND speeds up the body's reactions

  • 121. 
    The response of the immune system the second time an invader is encountered is called
    • A. 

      The anamnestic response

    • B. 

      The effector response

    • C. 

      The enhanced response

    • D. 

      None of the choices

  • 122. 
    The virulence factors of a pathogen are established by how strong or weak a patient's body defenses are at the time of infection.
    • A. 

      True

    • B. 

      False

  • 123. 
    During phagocytosis, intracellular digestion begins as soon as the phagosome is formed
    • A. 

      True

    • B. 

      False

  • 124. 
    Human B lymphocytes mature in an intestinal region called the bursa.
    • A. 

      True

    • B. 

      False

  • 125. 
    The production of interferon will protect the host cell from a viral infection.
    • A. 

      True

    • B. 

      False

  • 126. 
    After secreting antibodies during an immune response, plasma cells then differentiate into memory cells.
    • A. 

      True

    • B. 

      False

  • 127. 
    A person who is Rh- will have anti-Rh antibodies in their serum from early infancy.
    • A. 

      True

    • B. 

      False

  • 128. 
    When an infected person is in the incubation period, that person cannot transmit the pathogen to others.
    • A. 

      True

    • B. 

      False

  • 129. 
    Eczema is an autoimmune disorder.
    • A. 

      True

    • B. 

      False

  • 130. 
    The secondary response to an antigen is faster and bigger than the primary response.
    • A. 

      True

    • B. 

      False

  • 131. 
    Inflammation responses are orchestrated by the immune system and are part of the body's third line of defense.
    • A. 

      True

    • B. 

      False

  • 132. 
    Which class of antibody accounts for the bulk of the circulating antibody?
    • A. 

      IgA

    • B. 

      IgD

    • C. 

      IgG

    • D. 

      IgE

  • 133. 
    The beauty of specific immunity is the production of __________ that provides long-lasting protection.
    • A. 

      Antibodies

    • B. 

      Plasma cells

    • C. 

      T helper cells

    • D. 

      Memory cells

    • E. 

      Phagocytotic cells

  • 134. 
    The cytokine produced by animal cells in response to viral infections
    • A. 

      Complement

    • B. 

      Lysozyme

    • C. 

      Histamine

    • D. 

      Interferon

  • 135. 
    Which is the first antibody class made during the primary response to an antigen?
    • A. 

      IgA

    • B. 

      IgM

    • C. 

      IgG

    • D. 

      IgE

  • 136. 
    When an infectious disease cannot spread in a population because it lacks a significant number of susceptible hosts, the phenomenon is referred to as
    • A. 

      Protected population

    • B. 

      Active immunity

    • C. 

      Passive immunity

    • D. 

      Herd immunity

  • 137. 
    Diseases constantly present in a population are
    • A. 

      Epidemic

    • B. 

      Chronic

    • C. 

      Latent

    • D. 

      Endemic

  • 138. 
    The four classic signs and symptoms of inflammation include all the following except
    • A. 

      Redness

    • B. 

      Warmth

    • C. 

      Swelling

    • D. 

      Pain

    • E. 

      Chills

  • 139. 
    The only class of antibody that can cross the placenta is
    • A. 

      IgA

    • B. 

      IgD

    • C. 

      IgG

    • D. 

      IgE

  • 140. 
    Diapedesis is the
    • A. 

      Loss of blood due to hemorrhaging

    • B. 

      Production of only red blood cells

    • C. 

      Production of white blood cells, red blood cells and platelets

    • D. 

      Plugging of broken vessels to stop bleeding

    • E. 

      Migration of white blood cells from the blood out to the tissues

  • 141. 
    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

  • 142. 
    Which of the following is not a method of adhesion?
    • A. 

      Fibriae

    • B. 

      Surface proteins

    • C. 

      Specialized receptors

    • D. 

      Adhesive slime or capsules

    • E. 

      Cilia

  • 143. 
    The immunoglobulin that is important in hypersensitivity reactions is
    • A. 

      IgA

    • B. 

      IgD

    • C. 

      IgD

    • D. 

      IgE

  • 144. 
    How long after initiation of a primary response do signifiant amounts of antibody appear in the blood?
    • A. 

      One day

    • B. 

      10-14 days

    • C. 

      4 weeks

    • D. 

      6 weeks

  • 145. 
    The chemical nature of exotoxins is that of a
    • A. 

      Protein

    • B. 

      Carbohydrate

    • C. 

      Lipid

    • D. 

      Lipopolysaccharide

  • 146. 
    The chemical nature of endotoxins is that of a
    • A. 

      Protein

    • B. 

      Nucleic acid

    • C. 

      Lipid

    • D. 

      Lipopolysaccharide

  • 147. 
    Which immunoglobulin class/es can fix complement?
    • A. 

      IgM only

    • B. 

      IgG only

    • C. 

      IgD only

    • D. 

      IgM and IgG

    • E. 

      IgE and IgA

  • 148. 
    The immunoglobulin/s found on the surface of B cells is/are
    • A. 

      IgM only

    • B. 

      IgG only

    • C. 

      IgD only

    • D. 

      IgM and IgD

    • E. 

      IgD and IgE

  • 149. 
    Which of the following statements is true?
    • A. 

      Evolution selects for the most virulent pathogens

    • B. 

      A successful pathogen never kills its host

    • C. 

      The primary goal of a pathogen is to kill its host

    • D. 

      A successful pathogen does not kill its host before it is transmitted

  • 150. 
    A vaccination is a good example of
    • A. 

      Naturally acquired passive immunity

    • B. 

      Naturally acquired active immunity

    • C. 

      Artificially acquired active immunity

    • D. 

      Artificially acquired passive immunity

  • 151. 
    The affect of "good" microbes against invading microbes is called
    • A. 

      Microbial antagonism

    • B. 

      Endogenous infection

    • C. 

      Infectious disease

    • D. 

      Axenic

    • E. 

      Gnotobiotism

  • 152. 
    The most numerous WBC's that have multilobed nuclei and are very phatocytic are
    • A. 

      Basophils

    • B. 

      Eosinophils

    • C. 

      Neutrophils

    • D. 

      Monocytes

    • E. 

      Lymphocytes

  • 153. 
    A person who has anti A and anti B serum antibodies will have blood type
    • A. 

      A

    • B. 

      B

    • C. 

      AB

    • D. 

      O

    • E. 

      Rh

  • 154. 
    Which process involves a more rapid synthesis and greatly increased titer of antibody when the immune system is subsequently exposed to the same antigen?
    • A. 

      Neutralization

    • B. 

      Opsonization

    • C. 

      Complement fixation

    • D. 

      Agglutination

    • E. 

      Amnamnestic response

  • 155. 
    Which of the following antibodies is a pentamer?
    • A. 

      IgA

    • B. 

      IgD

    • C. 

      IgM

    • D. 

      IgE

  • 156. 
    Tears protect the eyes by
    • A. 

      Flushing and lysozyme

    • B. 

      Inflammation

    • C. 

      Vasodilation

    • D. 

      Stimulating opsonization

    • E. 

      Flushing and lysozyme and vasodilation

  • 157. 
    The initial, brief period of early, general symptoms such as fatigue and muscle aches is the
    • A. 

      Prodromal period

    • B. 

      Period of convalescent

    • C. 

      Incubation period

    • D. 

      Period of illness

    • E. 

      Period of decline

  • 158. 
    Which of the following is one of the body's first lines of defense against infection?
    • A. 

      Increased production of certain hormones and changes in the blood circulation

    • B. 

      Several nonspecific amino acid toxins

    • C. 

      Several nonspecific antibodies

    • D. 

      Several nonspecific obstacles such as skin and mucous membranes

    • E. 

      None of the above

  • 159. 
    A substance that can elicit an immune response is called a(n)
    • A. 

      Complement

    • B. 

      Antibody

    • C. 

      Histamine

    • D. 

      Antigen

    • E. 

      Interferon

  • 160. 
    Which of the following cell types is specifically responsible for cell-mediated immunity?
    • A. 

      B Cells

    • B. 

      Macrophages

    • C. 

      T cells

    • D. 

      Neutrophils

    • E. 

      Natural killer (NK) cells

  • 161. 
    Antibodies are __________.
    • A. 

      Proteins

    • B. 

      Nucleic acids

    • C. 

      Amino acids

    • D. 

      Lipids

    • E. 

      Carbohydrates

  • 162. 
    Which of the following statements about antibodies is NOT true?
    • A. 

      Antibodies recognize and bind to particular antigens

    • B. 

      Antibodies assist in destroying particular antigenic particles

    • C. 

      The body can produce only a very limited number of different antibodies

    • D. 

      All of the polypeptide chains of an antibody molecule have both a V region and a C region

    • E. 

      Antibody molecules are constructed from four molecular chains

  • 163. 
    The basic function of T cells is to identify and destroy invaders in our __________.
    • A. 

      Immune system

    • B. 

      Blood or lymph

    • C. 

      Brain

    • D. 

      Interstitial fluid

    • E. 

      Cells

  • 164. 
    Which of the following cell types is specifically responsible for humoral immunity?
    • A. 

      B Cells

    • B. 

      Macrophages

    • C. 

      T cells

    • D. 

      Neutrophils

    • E. 

      Natural killer (NK) cells

  • 165. 
    Which type of immune response is always disadvantageous to a person?
    • A. 

      Inflammatory

    • B. 

      Autoimmune

    • C. 

      Cell-mediated

    • D. 

      Humoral-mediated

    • E. 

      All immune responses are advantageous

  • 166. 
    A researcher detects interferon in a laboratory rat and concludes that __________.
    • A. 

      Cancerous cells are present in the rat

    • B. 

      The rat's diet is deficient in calcium

    • C. 

      The complement system is activated by exposure to an antigen

    • D. 

      The rat has, or recently had, a viral infection

    • E. 

      None of the above

  • 167. 
    Which of the following triggers our nonspecific defense system?
    • A. 

      Inflammation

    • B. 

      Passive immunity

    • C. 

      Cell-mediated immunity

    • D. 

      Movement of erythrocytes to the affected site

    • E. 

      Active immunity

  • 168. 
    The transfer of antibodies from breast milk to an infant is an example of __________ immunity.
    • A. 

      Passive

    • B. 

      Humoral

    • C. 

      Cell-mediated

    • D. 

      Active

    • E. 

      Nonspecific

  • 169. 
    Anaphylactic shock is an example of an __________.
    • A. 

      Immunodeficiency disease

    • B. 

      Acquired autoimmune disease

    • C. 

      Acquired immunodeficiency disease

    • D. 

      Allergic response

    • E. 

      Autoimmune disease

  • 170. 
    Complement proteins assist the immune response by __________.
    • A. 

      Coating the surface of microbes, thus making it easier for macrophages to phagocytize them

    • B. 

      Reducing inflammation

    • C. 

      Enhancing the effects of antibiotics

    • D. 

      All of the above

    • E. 

      None of the above

  • 171. 
    Which of the following substances does a cytotoxic T cell secrete to destroy a target cell?
    • A. 

      Pyrogen

    • B. 

      Perforin

    • C. 

      Complement

    • D. 

      Interferon

    • E. 

      Antibodies

  • 172. 
    Which of the following is a major function of natural killer (NK) cells?
    • A. 

      To attack virus-infected cells in a nonspecific way

    • B. 

      To phagocytize microorganisms that have been tagged with antibodies

    • C. 

      To tag pathogenic microorganisms with antibodies

    • D. 

      To attack virus-infected cells in an antigen-specific way

    • E. 

      To attack and kill pathogenic microorganisms in a nonspecific way

  • 173. 
    What kinds of cells wander the interstitial fluid eating whatever bacteria and virus-infected cells they encounter and recognize?
    • A. 

      Leukocytes

    • B. 

      Macrophages

    • C. 

      Monocytes

    • D. 

      Natural killer (NK) cells

    • E. 

      Interferons

  • 174. 
    Which of the following kinds of protein circulates in the blood and coats the surfaces of microbes to make them more susceptible to engulfment by macrophages?
    • A. 

      Antigen

    • B. 

      Complement

    • C. 

      Pyrogen

    • D. 

      Interferon

    • E. 

      Prostaglandin

  • 175. 
    Which of the following types of cells does HIV preferentially infect?
    • A. 

      Cytotoic T cells

    • B. 

      Memory cells

    • C. 

      Helper T cells

    • D. 

      Macrophages

    • E. 

      Natural killer (NK) cells

  • 176. 
    Which of the following diseases is NOT thought to be an autoimmune disease?
    • A. 

      Systemic lupus erythematosus

    • B. 

      Cancer of the bone marrow

    • C. 

      Multiple sclerosis

    • D. 

      Insulin-dependent diabetes

    • E. 

      Rheumatoid arthritis

  • 177. 
    Why do diseases involving widespread infection usually result in a fever?
    • A. 

      The microorganisms trick the brain's temperature control center (hypothalamus) into creating a hot environment that favors their growth.

    • B. 

      The inflammatory and immune responses result in extra heat production

    • C. 

      The rapid multiplication of the invading microorganisms results in extra heat production

    • D. 

      The brain's temperature control center responds to inflammation by creating a hot environment unfavorable to microorganisms

    • E. 

      None of the choices are correct

  • 178. 
    What is a primary immune response?
    • A. 

      The immune response elicited by the primary antigen of a disease-causing microorganism

    • B. 

      The immune response elicited by the first exposure of memory cells to a particular antigen

    • C. 

      The immune response elicited by the first exposure of lymphocytes to a particular antigen

    • D. 

      The immune response elicited by the primary antibody of a disease-causing microorganism

    • E. 

      The production of primary-type antibody in the first day of exposure to a microorganism

  • 179. 
    Which of the following is NOT an activity of antibodies?
    • A. 

      Neutralization of the invader

    • B. 

      Physically blocking antigens

    • C. 

      Phagocytosis of invaders

    • D. 

      Clumping of invader cells

    • E. 

      Activation of complement proteins

  • 180. 
    Which of the following compounds are mast cells specialized to secrete?
    • A. 

      Interferon

    • B. 

      Perforin

    • C. 

      Histamine

    • D. 

      Complement

    • E. 

      Allergens

  • 181. 
    When you cut yourself, the damaged cells immediately release which of the following chemical alarm signals?
    • A. 

      Anti-interferon

    • B. 

      Histamine

    • C. 

      Pyrogens

    • D. 

      Complement

    • E. 

      Interferon

  • 182. 
    Which of the following cell types initiates a secondary immune response?
    • A. 

      Immature leukocytes

    • B. 

      Memory cells

    • C. 

      Plasma cells

    • D. 

      Natural killer (NK) cells

    • E. 

      Effector cells

  • 183. 
    The symbiotic relationship wherein both partners benefit is termed
    • A. 

      Commensalism

    • B. 

      Parasitism

    • C. 

      Independence

    • D. 

      Mutualism

  • 184. 
    The idea that communicable diseases were caused by the passage of living things from one person to another was first put forth by
    • A. 

      Fracastorius

    • B. 

      Pasteur

    • C. 

      Thucydides

    • D. 

      Leeuwenhoek

  • 185. 
    The interaction of all organisms within a biological community is called a(n)
    • A. 

      Dialogue

    • B. 

      Chat room

    • C. 

      Ecosystem

    • D. 

      Relationship

  • 186. 
    A relationship in which one partner benefits and the other is harmed is termed
    • A. 

      Commensalism

    • B. 

      Parasitism

    • C. 

      Independence

    • D. 

      Mutualism

  • 187. 
    The resident microbial population of the human fetus is
    • A. 

      Zero

    • B. 

      Sparse

    • C. 

      Complex

    • D. 

      Symbiotic

  • 188. 
    Which of the following is true about the role normal flora play in maintaining host health?
    • A. 

      They provide a surface that is incompatible for attachment of an invader

    • B. 

      They establish a competition for nutrients and vitamins

    • C. 

      They produce antimicrobial substances

    • D. 

      They stimulate the immune system

    • E. 

      All of the above are true

  • 189. 
    Which of the following members of the normal flora inhibits the growth of Corynebacterium diphtheriae by producing hydrogen peroxide?
    • A. 

      E. coli

    • B. 

      Streptococcus species

    • C. 

      Staphylococci species

    • D. 

      Propionibacterium species

  • 190. 
    Which of the following members of the normal flora inhibits the growth of bacteria by production of fatty acids from lipids?
    • A. 

      E. coli

    • B. 

      Streptococcus pyogenes

    • C. 

      Staphylococcus epidermidis

    • D. 

      Propionibacterium species

    • E. 

      C and d

  • 191. 
    Which of the following may inhibit the activity of normal flora and allow pathogens to become established?
    • A. 

      Peroxides

    • B. 

      Acids

    • C. 

      Fatty acids

    • D. 

      Antibiotics

  • 192. 
    A diet high in meat leads to a population of normal flora with an increased number of
    • A. 

      E. coli

    • B. 

      Streptococci pyogenes

    • C. 

      Staphylococci epidemidis

    • D. 

      Bacteroides species

    • E. 

      C and D

  • 193. 
    Growth of a parasitic organism in or on the host is referred to as
    • A. 

      Colonization

    • B. 

      Infection

    • C. 

      Pathogenism

    • D. 

      Mutualism

  • 194. 
    A member of the normal flora that becomes an opportunist if it invades the urinary bladder is
    • A. 

      P. vulgaris

    • B. 

      C. diptheria

    • C. 

      S. typhimurium

    • D. 

      E. coli

  • 195. 
    An obligate intracellular pathogen may
    • A. 

      Only survive outside the cell

    • B. 

      Survive inside or outside the cell

    • C. 

      Survive in the interstitial tissue

    • D. 

      May only survive and grow inside a cell

  • 196. 
    Attributes of an organism that promote pathogenicity are called
    • A. 

      Disease factors

    • B. 

      Colonization factors

    • C. 

      Mutualistic

    • D. 

      Virulence factors

  • 197. 
    Avirulent organisms are
    • A. 

      More likely to cause disease

    • B. 

      More likely to cause severe disease

    • C. 

      Unable to cause disease

    • D. 

      Pathogenic

  • 198. 
    Which of the following may be considered virulence factors?
    • A. 

      Adhesins

    • B. 

      Capsules

    • C. 

      Endotoxins

    • D. 

      Proteases

    • E. 

      All of the above

  • 199. 
    Which of the following does S. pneumoniae use to survive in the host?
    • A. 

      Plasmids

    • B. 

      Pili

    • C. 

      Flagella

    • D. 

      Capsules

  • 200. 
    Which of the following would be considered a sign of a disease?
    • A. 

      Headache

    • B. 

      Pain

    • C. 

      Nausea

    • D. 

      Fever of 39°C

  • 201. 
    People who carry and may spread pathogenic organisms without any overt symptoms of illness are called
    • A. 

      Primary infections

    • B. 

      Secondary infections

    • C. 

      Mutualists

    • D. 

      Carriers

  • 202. 
    The spread of toxin via the circulation is called
    • A. 

      Septicemia

    • B. 

      Bacteremia

    • C. 

      Sepsis

    • D. 

      Toxemia

  • 203. 
    If a disease affects only a human and not an animal, then it would be difficult to fulfill Koch's postulate number ___.
    • A. 

      1

    • B. 

      2

    • C. 

      3

    • D. 

      4

  • 204. 
    Transmission of an infectious disease by touching, handshaking, or kissing is considered
    • A. 

      Direct contact

    • B. 

      Indirect contact

    • C. 

      Infectious connection

    • D. 

      Communicable actions

  • 205. 
    Which of the following is considered an indirect mode of transmission?
    • A. 

      Sexual intercourse

    • B. 

      Touching

    • C. 

      Handshaking

    • D. 

      Insect bites

  • 206. 
    Fomites are involved in
    • A. 

      Direct contacts

    • B. 

      Indirect contacts

    • C. 

      Direct infectious connections

    • D. 

      Communicable actions

  • 207. 
    The number of organisms necessary to insure infection is termed the
    • A. 

      Infectious dose

    • B. 

      Fatal number

    • C. 

      Minimum lethal dose

    • D. 

      Pathogenic number

  • 208. 
    The portal of entry
    • A. 

      Has no effect on the establishment of an infection

    • B. 

      Plays a role in whether an infection will be established

    • C. 

      May be the skin or respiratory tract

    • D. 

      May be the same as the portal of exit

    • E. 

      B, c and d

  • 209. 
    Typically, adhesins
    • A. 

      Are found on the pili

    • B. 

      Help bacteria attach to host cells

    • C. 

      Are proteins

    • D. 

      Are found on host cells

    • E. 

      A, b and c

  • 210. 
    Density-dependent expression of virulence factors is called
    • A. 

      Pathogenicity

    • B. 

      Size dependency

    • C. 

      Key number

    • D. 

      Quorum sensing

  • 211. 
    C5a peptidase
    • A. 

      Is a virulence factor

    • B. 

      Synthesizes C5a

    • C. 

      Is produced by the host cell in response to infection

    • D. 

      Is a molecule promoting chemotaxis

    • E. 

      A and d

  • 212. 
    Which of the following is/are true about endotoxins?
    • A. 

      Lipid A is the toxic portion of the molecule

    • B. 

      The toxic effects depend on the bacteria from which it came

    • C. 

      The lipid A is immunogenic

    • D. 

      The O antigens are the same for all bacteria

    • E. 

      B and d

  • 213. 
    The lack of susceptibility to diseases of other species in humans may be due to the
    • A. 

      Secretion of exotoxins

    • B. 

      Presence of endotoxins

    • C. 

      Action of IL-2

    • D. 

      Lack of receptors that are recognized by adherence factors

  • 214. 
    Bacteria may survive phagocytosis by
    • A. 

      Preventing fusion of the lysosome with the phagosome

    • B. 

      Preventing acidification of the phagolysosome

    • C. 

      Producing comet tails

    • D. 

      Preventing fusion of two phagosomes

    • E. 

      A and b

  • 215. 
    Which is true about superantigens?
    • A. 

      They are a type of exotoxin

    • B. 

      They bind to MHC class II antigen on T cells

    • C. 

      They enhance specific antibody production

    • D. 

      They are processed intracellularly

    • E. 

      A and b

  • 216. 
    Which is/are true about viruses?
    • A. 

      They may suppress the production of MHC Class I protein

    • B. 

      They may produce an MHC Class I mimic protein

    • C. 

      They may prevent cell suicide

    • D. 

      They may bind to MHC class II antigens

    • E. 

      A, b and c

  • 217. 
    An example of genetic variation used in pathogen survival may be
    • A. 

      Production of a comet's tail

    • B. 

      Protease production

    • C. 

      Inhibition of MHC Class I antigen production

    • D. 

      Changing the pilus type

    • E. 

      A and b

  • 218. 
    Which is true about botox?
    • A. 

      It is an endotoxin

    • B. 

      It is produced by S. aureus

    • C. 

      It may cause botulism

    • D. 

      It is useful in treating conditions related to muscle contractions

    • E. 

      C and d

  • 219. 
    In Gram-negative bacteria, many of the genes required for pathogenicity are
    • A. 

      Located far from one another on the chromosome

    • B. 

      Individually transferred between bacteria

    • C. 

      Located close together on chromosomes in regions called pathogenicity islands

    • D. 

      Located on separate chromosomes

    • E. 

      B and c

  • 220. 
    Microbes may evade host defensive responses by
    • A. 

      Inhibiting genetic variation

    • B. 

      Mimicking host materials

    • C. 

      Taking over the cell's myosin

    • D. 

      Encouraging fusion of the phagosome with the lysosome

    • E. 

      A and c

  • 221. 
    Infection always leads to disease.
    • A. 

      True

    • B. 

      False

  • 222. 
    A disease is an infection that impairs the normal state of health.
    • A. 

      True

    • B. 

      False

  • 223. 
    During incubation and convalescence a person may still spread infectious organisms.
    • A. 

      True

    • B. 

      False

  • 224. 
    The infectious dose of most pathogens is about equal.
    • A. 

      True

    • B. 

      False

  • 225. 
    A strong attachment of a microorganism to a host cell automatically leads to disease.
    • A. 

      True

    • B. 

      False

  • 226. 
    High concentrations of some bacteria are necessary for successful invasion because only at high density are their virulence genes expressed.
    • A. 

      True

    • B. 

      False

  • 227. 
    Only Gram-positive bacteria produce exotoxins.
    • A. 

      True

    • B. 

      False

  • 228. 
    The two main functions of the lymphatic system are
    • A. 

      Returning tissue fluid to the circulatory system and coagulating blood

    • B. 

      Coagulating blood and fighting infections

    • C. 

      Returning tissue fluid to the circulatory system and fighting infections

    • D. 

      Producing hormones that regulate the immune system and coagulating blood

    • E. 

      Producing hormones that regulate the immune system and fighting infections

  • 229. 
    Antibodies
    • A. 

      Consist of three polypeptide chains

    • B. 

      Assist in destroying particular antigens

    • C. 

      Are generalists in that any antibody can bind to any antigen

    • D. 

      Are shaped like the letter B

    • E. 

      All of the above