BioSc221/325 Exam 4 WS2000 Name ______________________________Multiple choice. (1 point each) Choose the one best answer to each of the following questions.1. ___Which of the following areas of the body do not have a resident microbial flora?A. upper respiratory tractB. eyesC. bladderD. ear2. ___ Which statement(s) is/are true?A. Gram positive organisms dominate the microflora.B. Propionibacterium acnes is a normal resident of the skin.C. Lipophilic yeasts are sometimes normal residents of the skin.D. All of the above3. ___ Which of the following phenomena is/are associated with the metabolic and biochemical activities of the intestinalmicroflora?A. Vitamin synthesisB. Production of aminesC. Production of organic acidsD. All of the above.4. ___ Which of the following organisms is most likely to be implicated in dental caries?A. Staphylococcus aureusB. Staphylococcus epidermidisC. Streptococcus sobrinusD. Escherichia coli5. ___ Which statement is true about an exotoxin?A. It is mostly produced by gram negative bacteria.B. Its LD50 may be as low as the picogram level.C. It is composed primarily of carbohydrate.D. It is LPS associated.6. ___ Gingivitis is a(n)A. early form of bone loss.B. inflammation of the soft tissue.C. periodontal disease.D. all of the above.7. ____ Which of the following is an enterotoxin?A. Cholera toxinB. Diphtheria toxinC. Plague toxinD. LPS of Salmonella8. ____ Which exotoxin binds to inhibitory neurons, blocking the release of glycine, and resulting in twitching paralysis?A. Diphtheria toxinB. Tetanus toxinC. Botulinum toxinD. Cholera toxin9. ___ Which of the following is/are associated with bacterial invasion?A. CollagenaseB. PhospholipaseC. HemolysinD. All of the above10. ____ The toxin of Clostridium tetani is classified as a(n)A. EndotoxinB. CytotoxinC. EnterotoxinD. Neurotoxin11. ____ The substance in the LPS for gram negative bacteria that is responsible for the effects of the toxin isA. The core polysaccharideB. Lipid AC. The O-polysaccharideD. the dideoxysugars12. ___ Antibacterial substances found in the mouth includeA. LysozymeB. LysozomeC. LipaseD. All of the above13. ___ Hemolysins are lytic agents thatA. lyse red blood cellsB. lyse white blood cellsC. lyse bacterial cellsD. destroy viruses14. ___ Which of the following virulence factors are important for pathogenicity in Streptococcus pneumoniae?A. capsuleB. exotoxin PC. hemolysinD. all of the above15. ___ The most common of all nosocomial infections are found in theA. bloodB. reproductive tractC. urinary tractD. respiratory tract16. ___ MacConkey's agar and EMB agar areA. selective but not differentialB. differential but not selectiveC. both selective and differentialD. neither selective nor differential17. ___ Which of the following tests would allow the specific identification of a single microbe under the microscope?A. fluorescent antibody (FA)B. radioimmunoassay (RIA)C. enzyme-linked immunosorbent assay (ELISA)D. agglutination.18. ___ In which type of medium will an indicator dye be found?A. selective but not differentialB. differential but not selectiveC. both selective and differentialD. neither selective nor differential19. ___ Transmission of an infectious disease is most likely during theA. incubation periodB. prodromal periodC. acute periodD. decline period20. ___ Diseases that naturally occur in animals and accidentally in humans are calledA. nosocomial infectionsB. zoonosisC. vector infectionsD. muduranes21. ___ An inanimate object that transmits infectious agents between hosts is most appropriately called aA. fomiteB. carrierC. vectorD. reservoir22. ___ A tick transmitting Rickettsia rickettsii to a human is an example of a(n)A. endemic vectorB. opportunistic pathogenC. biological vectorD. mechanical vector23. ___ According to recent statistical studies in the US, a person is most apt to acquire a serious infectionA. in a hospitalB. at homeC. At schoolD. While travelling24. ___ The federal agency responsible for disease surveillance in the US is theA. USDAB. FDAC. CDCD. EPA25. ___ Which of the following diseases would not normally be spread by a common source?A. measlesB. typhoid feverC. dysenteryD. cholera26. ___ Which of the following is/are considered direct contact infections?A. syphilisB. gonorrheaC. AIDSD. all of the aboveShort answer. (1 or 2 points each)(1) The relative ability of a pathogen to cause disease of greater or lesser severity is that pathogen's _____________________.(1) When the virulence of a pathogen is decreased of even completely lost, the pathogen is said to be ____________________.(1) A polymer coat consisting of a dense, well-defined layer closely surrounding the cell is known as the _________________.(1) A large number of bacteria in the bloodstream results in a condition known as _________________________.(1) Describe one of the properties of microorganisms that grow well on the skin.(1) Why are hospital patients more susceptible than "normal" individuals to infectious agents?(1) Why does Lactobacillus inhabit the stomach?(2) What are the four possible outcomes resulting from the initial contact with a microbe?(1) What is an infectious dose?(2) Describe the stages of infection and what is happening in each stage.(1) Why do Gram-positive Bacteria not produce endotoxins?(1) Why are the endotoxins generally not as potent as the exotoxins?(2) Describe two of the three types of fever.(1) How might preexisting infections compromise an otherwise healthy host?(2) Distinguish between selective and differential identification methods. Give an example of a medium used for each purpose.(1) Why does the antibody titer to an organism rise during convalescence?(1) What advantages do agglutination tests have over other immunoassays?(1) Distinguish between an endemic disease, an epidemic disease, and a pandemic disease.(1) Distinguish between acute and chronic carriers.(1) How does herd immunity prevent a non-immune individual from acquiring a disease?Short Essay Questions. Please answer 4 of the following 5 short essay questions (5 points each - 5 bonus points possible foranswering all five questions)Describe five factors that are important in the emergence or reemergence of potential pathogens?List the three major types of exotoxins and compare exotoxins and endotoxins.What have we learned about the function of the resident microflora through the use of axenic animals?Explain how an organism may become attenuated. Define the role of attenuated organisms in