OLD MCQS General micro Flashcards
34- How do effector T-cells differ from naïve T-cells?
a. They can be triggered without the need for antigen-presenting cell.
b. They can be triggered without the need for co-stimulatory molecule.
c. They can be triggered without the need for CD4 or CD8 molecules.
d. They can be triggered without the need for signal transmission by CD
b. They can be triggered without the need for co-stimulatory molecule.
35- Which cytokine has an immunosuppressive action?
a. IL-2
b. IL-12
c. TGF-B
d. TNF-a
c. TGF-B
36- Which complement component is the most chemotactic for phagocytes?
a. C1
b. C3a
c. C4
d. C5b
b. C3a
37- Which immunity develops following a subclinical infection?
a. Artificial active immunity
b. Artificial passive immunity
c. Natural active immunity
d. Natural passive immunity
c. Natural active immunity
38- Regarding the vesicular pathogens, which statement is CORRECT?
a. They are degraded in the cytoplasm.
b. Their peptides bind to MHC I molecules.
c. They are presented to CD8-T cells.
d. They include intracellular bacteria.
d. They include intracellular bacteria.
40- What is meant by an isograft?
a. A transplant from one part of the body to another
b. A transplant from one person to a genetically identical person
c. A transplant from one species to the same species
d. A transplant from one species to another species
b. A transplant from one person to a genetically identical person
42- Regarding tolerance, which statement is CORRECT?
a. Induction of tolerance is easier in the prenatal period.
b. Administration of low doses of antigen usually tolerizes B cells.
c. Giving the antigen with an immunosuppressant inhibits the induction of
d. Particulate protein antigens are more tolerogenic than soluble ones.
a. Induction of tolerance is easier in the prenatal period.
43- Which cells are important in the development of delayed hypersensitivity
a. Basophils
b. B cells
c. Mast cells
d. T helper-1 cells
d. T helper-1 cells
44- Which virus is a DNA encogenic virus?
a. Cytomegalovirus
b. Epstein-Barr virus
c. Human immunodeficiency virus
d. Human T-cell lymphotropic virus
a. Cytomegalovirus
45- Which HIV antigen is important for viral binding to CD4 receptor?
a. Glycoprotein 41
b. Glycoprotein 120
e. Glycoprotein 160
d. P24 antigen
b. Glycoprotein 120
48- Serum sickness is an example of which type of hypersensitivity?
a. Anaphylactic hypersensitivity
b. Cell-mediated hypersensitivity
c. Cytolytic hypersensitivity
d. Immune-complex hypersensitivity
d. Immune-complex hypersensitivity
1- Which structure is responsible for bacterial motility:
a) Fimbria
b) Flagellum
c) Glycocalyx
d) Mesosome
b) Flagellum
2- Which component is unique for bacterial spores:
a) Lipid A
b) Outer membrane
c) Dipicolinic acid
d) Teichoic acid
c) Dipicolinic acid
3- Which term describes bacteria that grow at refrigeration temperature
a) Mesophile
b) Capnophile
c) Micro-aerophile
d) Psychrophile
d) Psychrophile
4- Which event occurs SOLELY in a temperate bacteriophage cycle:
a) Generalized transduction
b) Intracellular synthesis of phage components
c)) Lysis of the bacterial cell
d) Lysogenic conversion
d) Lysogenic conversion
5- Regarding plasmids, which statement is True:
a) They are extrachromosomal, double stranded DNA molecules
b) They are much larger than the bacterial chromosome.
c) They are non-replicating transferable DNA segments.
d) They encode properties that are essential for bacterial growth
a) They are extrachromosomal, double stranded DNA molecules
6- During conjugation, which structure mediates the transfer of genetic material:
a) Capsule
b) Mesosome
c) Ribosome
d) Sex pilus
d) Sex pilus
7- Concerning endotoxins, which statement is True:
a) They are encoded by genes located on plasmids.
b) They are mainly found in Gram-positive organisms.
c) They are only liberated upon cell disintegration
d) They can be converted into toxoid.
c) They are only liberated upon cell disintegration
8- Which virulence factor is the most important against phagocytosis:
a Capsule
b) Glycocalyx
c) Lecithinase
d) Leukocidin
a Capsule
9- Which term describes rifampicin administration to close contacts of meningococcal meningitis patients:
a) Chemoprophylaxis
b) Combined therapy
c) Empiric therapy
d) Therapeutic application
a) Chemoprophylaxis
10- Where do lymphocytes undergo activation:
a) Bone marrow
b) Liver
c) Lymph nodes
d) Thymus gland.
c) Lymph nodes
11- Which feature is characteristic of innate immunity:
a) It does not increase with repeated exposures.
b) It is highly specific against a particular pathogen.
c) It responds to bacteria and fungi, but not viruses.
d) It takes several days to become fully functional.
a) It does not increase with repeated exposures.
12- Concerning natural killer cells, which statement is True:
a) They are capable of killing virally-infected cells
b) They are considered part of the acquired immunity.
c) They are specific in their mechanism of killing
d) They can phagocytose tumor cells.
a) They are capable of killing virally-infected cells
13- Which statement is Incorrect regarding immunity to extracellular bacteria:
a) NK cells can exert direct cytotoxic killing of extracellular bacteria.
b) Such bacteria are rapidly killed by microbicidal mechanisms of phagocytes.
c) The main protective specific immune response is humoral immunity
d) Agglutination of bacteria by antibodies prevents their spread.
a) NK cells can exert direct cytotoxic killing of extracellular bacteria.
14- What is the most important antigen-presenting cell:
a) Dendritic cell
b) Eosinophil
c) Natural killer cell
d) Neutrophil
a) Dendritic cell
15- Regarding MHC molecules, which statement is True:
a) B cells have both MHC I and MHC II molecules.
b) MHC I molecules are found on red blood corpuscles
c) MHC I molecules are present on professional antigen presenting cells only.
d) MHC II molecules are present on the surface of all nucleated cells of the body
a) B cells have both MHC I and MHC II molecules.
16- Which event is a well-known action of IL-12:
a) Activation and growth of B-cells
b) Chemotaxis and activation of neutrophils
c) Differentiation of Th cells into Th1 cells
d) Suppression of the synthesis of proinflammatory cytokines.
c) Differentiation of Th cells into Th1 cells
17- Which cytokine inhibits the development of Th2 cells:
a) IFN-Y
b) IL-6
c) IL-4
d) TNF-a
a) IFN-Y
18- Which antibody provides local immunity at the mucosal surfaces:
a) lgA
b) IgD
c) IgE
d) IgG
a) lgA
19- Which surface molecule delivers the first signal for B-cell activation:
a) B cell receptor
b) B7
c) CD40
d) MHCII
a) B cell receptor
20- Which outcome is expected to occur after complement activation:
a) Agglutination
b) Neutralization
c) Opsonization
d) T-cell proliferation
c) Opsonization
21- Concerning active immunity, which statement is True:
a) It includes development of an immunological memory
b) It is present in all individuals, against all microorganisms.
c) Its onset starts immediately after infection.
d) The duration of its protection is usually short
a) It includes development of an immunological memory
22- Which antibodies represent passive acquired immunity:
a) Antibodies developing after clinically manifest infection
b) Antibodies passing from mother to newborn baby.
c) Antibodies produced after subclinical infection
d) Antibodies produced following vaccine administration
b) Antibodies passing from mother to newborn baby.
23- Which statement best describes persistent viral infections:
a) They are characterized by long incubation periods that may last months or years
b) They are local viral infections with the appearance of clinical signs and symptoms
c) The virus can be continuously detected with mild or no clinical symptoms.
d) The virus persists in a dormant form and may flare up intermittently to produce disease
c) The virus can be continuously detected with mild or no clinical symptoms.
24- What is the most important cell of the innate immune system in combating fungi:
a) Eosinophil
b) Monocyte
c) Natural killer cell
d) Neutrophil
d) Neutrophil
25- Which component is found in the cell membrane of most fungi:
a) Chitin
b) Ergosterol
c) Lipopolysaccharide
d) Peptidoglycan
b) Ergosterol
26- What makes a substance more immunogenic:
a) Its administration in a very high dose
b) Its administration by the intravenous route
c) Its natural chemical complexity
d) Its similarity to host cellular antigens
c) Its natural chemical complexity
27- In which phase of bacterial growth are enzymes formed?
a. Decline phase
b. Exponential phase
c. Lag phase
d. Stationary phase
c. Lag phase
28- Which of the following is responsible for lysogenic conversion?
a. Lysosome
b. Plasmid
c. Prophage
d. Sex pilus
c. Prophage
29- Which statement is CORRECT Concerning conjugative plasmids
a. Their copy number is above 30.
b. They are common in Gram-positive cocci
c. They are usually small in size
d. They carry the F factors.
d. They carry the F factors.
30- Which type of bacterial variation depends on competence?
a. Conjugation
b. Generalized transduction
c. Mutation
d. Transformation
d. Transformation
31- What makes an organism intrinsically resistant to antimicrobial agents?
a. Alteration of 50S ribosomal subunit
b. Lacking the receptor for the antibiotic
c. Loss of cell membrane porins
d. Production of ß-lactamase enzyme
b. Lacking the receptor for the antibiotic
32- Concerning localized viral infections, which statement is CORRECT?
a. They have relatively a long incubation period
b. They are followed by lifelong immunity
c. Secretory immunoglobulin A involved.
d. Viraemia is a characteristic feature.
c. Secretory immunoglobulin A involved.
33- Which cell type is particularly important in the defense against parasitic infections?
a. Eosinophil
b. Macrophage
c. Monocyte
d. Neutrophil
a. Eosinophil
