Microbiology Objective Questions 486x2f

Objective Questions 1) 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. 2) 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

Lysozyme

D)

E)

None of the above 3) 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. 4) Which of the following exhibits the highest phagocytic activity? A) Neutrophils B) Erythrocytes C) Lymphocytes D) Basophils

E)

Eosinophils 5) Which of the following is not a characteristic of inflammation? A) Redness

Pain

Local heat

Fever

B)

C)

D)

E)

Swelling

6) All of the following can be determined from a differential count except A) The number of white blood cells. B) The numbers of each type of white blood cell. C) The number of red blood cells. D) The possibility of a state of disease. E) None of the above. 7) 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 8) Which of the following does not cause vasodilation? A) Kinins

B)

Prostaglandins C) Lysozymes D) Histamine E) None of the above 9) Which of the following choices shows the order in which white blood cells migrate to infected tissues? A) Macrophages  monocytes B) Lymphocytes  macrophages C) Neutrophils  macrophages D) Neutrophils  monocytes E) Macrophages  neutrophils 10) "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.

11) Which of the following statements is true? A) Alpha-interferon is an antiviral protein. B) Alpha-interferon promotes phagocytosis. C) Gamma-interferon causes cell lysis. D) Alpha-interferon acts against specific viruses. E) Beta-interferon attacks invading viruses. 12) Which of the following is found normally in serum? A) Complement B) Interferon C) Histamine D) Leukocytosis-promoting factor E) TLRs 13) 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 14) Which of the following is an effect of opsonization? A) Increased adherence of phagocytes to microorganisms B) Increased margination of phagocytes C) Increased diapedesis of phagocytes D) Inflammation E) None of the above 15) 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.

16) 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 17) Defensive cells such as T cells identify pathogens by binding: A) Toll-like receptors. B) Lysozyme. C) Complement. D) Lectins. E) Cytokines. 18) 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 19) Which of the following is not true of fixed macrophages? A) They are found in certain tissues and organs. B) They develop from neutrophils. C) They are cells of the mononuclear phagocytic system. D) They are mature monocytes. E) None of the above. 20) 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.

21) Which of the following is not an effect of histamine? A) Vasodilation B) Fever C) Swelling D) Redness E) Pain 22) 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 23) 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. 24) Which of the following statements is true? A) There are at least twenty complement proteins. B) All of the complement proteins are activated in serum. C) Factors B and D are complement proteins. D) Complement activity is antigen specific. E) Complement increases after immunization. 25) Complement fixation results in all of the following except A) Activation of C3b. B) Immune adherence. C) Acute local inflammation. D) Opsonization. E)

Cell lysis.

26) The mechanism of action of interferon includes all of the following except A) It binds to the surface of uninfected cells. B) It inactivates viruses. C) It initiates manufacture of another antiviral protein. D) It works in cells not producing INF. E) None of the above. 27) The alternative pathway for complement activation is initiated by A) Polysaccharides and C3b. B) C5-C9. C) Antigen-antibody reactions. D) Factors released from phagocytes. E) Factors released from damaged tissues. 28) The classical pathway for complement activation is initiated by A) Polysaccharides and C3b. B) C5-C9.

C) Antigen-antibody reactions. D) Factors released from phagocytes. E) Factors released from damaged tissues. 29) 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. 30) Neutrophils with defective lysosomes are unable to A) Move by chemotaxis. B) Migrate.

C)

Produce toxic oxygen products. D) Live.

E)

None of the above.

31) Vasodilation is caused by all of the following except A) Histamine. B) Complement. C) Prostaglandins. D) Leukotrienes. E) None of the above. 32) After ingesting a pathogen, lysosomal enzymes produce all of the following except A) Complement. B) O2-.

C)

H2O2

D)

OH∙. E) HOCl. 33) Activation of C5-C9 results in A) Activation of C3. B)

Fixation of complement. C) Leakage of cell contents. D) Phagocytosis. E) None of the above. 34) Which of the following is involved in adaptive immunity? A) Basophil B) Eosinophil C) Lymphocyte D) Monocyte E) Neutrophil 35) Which of the following is involved in resistance to parasitic helminths? A) Basophil B) Eosinophil C) Lymphocyte D) Monocyte E)

Neutrophil

36) Macrophages arise from which of the following? A) Basophil B) Eosinophil C) Lymphocyte D) Monocyte E) Neutrophil 37) Which one of the following does not belong with the others? A) Basophil B) Eosinophil C) Dendritic cell D) Natural Killer cell E) Neutrophil 38) Bacteria have siderophores that capture iron; humans counter this by A) Producing iron. B) Transferrins.

C) Toxin production. D) Iron-degrading enzymes. E) None of the above. 39) All of the following occur during inflammation. What is the first step? A) Diapedesis

B)

Margination C) Phagocyte migration D) Repair

E)

Vasodilation 40) The lectin pathway for complement action is initiated by A) Mannose on host membranes. B) Mannose on the parasite. C) Lectins of the parasite. D) Gram-negative cell walls. E)

None of the above.

41) 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. 42) 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 43) Which of the following is not true about the classical pathway of complement activation? A) C1 is the first protein activated in the classical pathway. B)

The C1 protein complex is initiated by antigen-antibody complexes. C) C3 is not involved in the classical pathway. D) Cleaved fragments of some of the proteins act to increase inflammation. E) C3b causes opsonization. 44) Chlamydia trachomatis can live inside white blood cells because it A) Inhibits formation of phagolysosomes. B) Inhibits phagocytosis. C) Prevents complement activation. D) Produces complement. E) Produces keratinase. 45) Bacterial enzymes such as catalase and superoxide dismutase can protect bacteria from A) Complement. B) Histamine.

Interferon.

C)

D)

Phagocytic digestion. E)

Phagocytosis.