1. The role played by major histocompatibility Complex-1 and -2 is toMediate immunoglobulin class switchingTransduce the signal to T cells following antigen recognitionPresent antigens for recognition by T cell antigen receptorsEnhances the secretion of cytokinesQuestion 1 of 20 2. All of the following statements concerning bacterial plaque are true, except:It is the key etiologic agent in the initiation of gingivitis and periodontal diseaseIt forms on a cleaned tooth within minutesIt is composed of solids (80%; 95% of which are bacteria) and water (20%)It is an accumulation of a mixed bacterial community in a dextran matrixQuestion 2 of 20 3. Percentage of alcohol commonly used for optimum disinfection:10-20%30-50%60-80%5-10%Question 3 of 20 4. Which cellular organelle listed below contains specialized enzymes whose functions involve hydrogen peroxide?NucleusMitochondriaMicrobodyGolgi complexQuestion 4 of 20 5. Correct order of phases in bacterial growth curve:Decline, log, lag, stationeryLog, lag, stationery, declineStationery, log, lag, declineLag, log, stationery, declineQuestion 5 of 20 6. Standard agar recommended for susceptibility tests using antibiotic sensitivity disksMueller Hinton AgarPLET AgarCastenada AgarCetrimide AgarQuestion 6 of 20 7. Streptococcus mutans can be distinguished from other streptococci byFermentation of mannitol and sorbitolProduction of extracellular polysaccharidesHemolysis on blood agarOptochin sensitivityQuestion 7 of 20 8. Which of the following represents the phenotypic expression of both alleles in a gene pairHybridizationLyonizationCodominancePenetranceQuestion 8 of 20 9. Candida albicans causes all of the following exceptMycetomaEndocarditisOral thrushMeningitisQuestion 9 of 20 10. The main advantage of active immunity is that resistance is:Short termNone of the aboveLong termAvailable immediatelyQuestion 10 of 20 11. First chemical barrier encountered by microorganism for common exposed sites -SkinLysozymeAcidic pHLactoseQuestion 11 of 20 12. Influenza is caused byOrthomyxo virus, which is a RNA virusOrthomyxo virus, which is a DNA virusParamyxo virus, which is a RNA virusParamyxo virus, which is a DNA virusQuestion 12 of 20 13. Techoic acid is present inCell wall of Gram positive organismsCytoplasm of Gram negative organismsCytoplasm of Gram positive organismsCell wall of Gram negative organismsQuestion 13 of 20 14. Staphylococci typically occurs inIrregular ClustersPairsChainsTetradsQuestion 14 of 20 15. The earliest identifiable cells of T-Cell Lineage during maturation areCD8+ Pre-T-CellsCD4+ Pre-T-CellsCD8+ Pro-T-CollsCD7 + Pro-T-CellsQuestion 15 of 20 16. Gram -ve bacteria stain during gram staining:ColorlessGreenBlue colorRed colorQuestion 16 of 20 17. Acute otitis media in children is most commonly due to:M. CatarrhalisSteptococcus pneumoniaStaphylococcus aureusH. InfluenzaQuestion 17 of 20 18. T lymphocytes are MOST directly involved in which of the following?Immune complex injuryComplement synthesisImmediate hypersensitivityContact dermatitisQuestion 18 of 20 19. All of the following agents have polysaccharide capsule related antigen antibody responses, except:MeningococcusBordetella PertusisHaemophillus InfluenzaPneumococcusQuestion 19 of 20 20. An example of naturally acquired passive immunity is:Tetanus immunizationImmune blood transfusionGamma globulin injectionPlacentral transfer of antibodiesQuestion 20 of 20 Loading...