Test Practice Questions to Study for Microbiology Chapter Four Part 2

Test Bank Key Multiple Choice Questions 1. E. coli has been isolated and cultured from three different individuals. Upon biochemical testing of these three cultures, you find that there are differences in some reactions. What is the best explanation of these differences? A. B. C. D. E. 2. These represent three different species of E. coli. This is normal genetic variation seen among strains of E. coli. Two of the cultures are mutants of the other. The other two cultures are not really E. coli. Mistakes have been made in the test interpretation. In which situation would a bacterium most likely have cytoplasmic inclusions? A. B. C. D. When producing an endospore When the cell is synthesizing flagella When the cell is starved for nutrients In a habitat abundant in nutrients True / False Questions 3. If you observe rod-shaped, pink cells on a slide that had just been Gram stained, you can assume that their cell envelope contains endotoxin. TRUE Multiple Choice Questions 4. You apply the acid-fast stain method to a patient's specimen, an aspirate from the lungs. Microscopic examination reveals a large number of bright pink-red bacillus-shaped bacteria in the smear. Which statement is true? A. B. C. D. 5. A patient has a serious respiratory infection. A sputum sample yielded a bacterium that did not have any peptidoglycan. You hypothesize that the identity of this microbe could possibly be ______. A. B. C. D. E. 6. This is the expected outcome for normal sputum. The patient has pneumonia. The patient has tuberculosis. The patient has an HIV infection. Streptococcus pneumoniae Mycobacterium tuberculosis Borrelia burgdorferi Staphylococcus aureus Mycoplasma pneumoniae You have made a smear of a bacterial culture and have performed the Gram stain on it. Looking at the organism under the microscope, you notice that the cells do not seem to be the dark blue-purple of a gram-positive reaction, but instead are light purple. Your staining procedure was performed correctly. What is your best explanation as to why the bacteria have stained this way? A. The bacteria were taken from an inappropriate medium, and a chemical is interfering with proper staining of the cells. B. There is something in the wall of the bacteria that has affected the uptake of the crystal violet into the cell wall, thereby staining it improperly. C. The specimen did not undergo heat fixation before staining; therefore, the primary dye does not stick properly to the wall. D. These are mutant bacteria which cannot be stained like other bacteria. 7. You have found a mutant of Streptococcus pneumoniae that has lost the ability to produce a capsule. If you inject this strain into a population of healthy mice, what prediction can you make about the consequences? A. B. C. D. 8. You've just isolated a new bacterium in pure culture, and you culture it on a general purpose medium where its cells have a coccobacillus morphology. When you examine the cells after culturing on a variety of differential media, you find that in some cases, the cells appear as coccobacillus, but in others, they can be filamentous, cocci, or club-shaped. The best explanation for this observation is that A. B. C. D. E. 9. the media were incubated at an incorrect temperature. the differential media are contaminated. the microscope is out of adjustment. the bacterium is pleomorphic. your culture has become contaminated. You've just isolated a new bacterium in pure culture, and you culture it on a general purpose medium where its cells have a rod-shape (bacillus) morphology. In addition to culturing it on solid media, you inoculate a slide to grow it as a biofilm. When you use confocal microscopy to image the biofilm, you observe that there are several cellular morphologies, ranging from coccus to coccobacillus to long bacillus. The best explanation for this observation is that A. B. C. D. 10. The mice will get a severe case of pneumonia and recover. The mice will remain healthy. The mice will die of pneumonia. The infection will respond to antiviral medication. the confocal microscope is out of adjustment. the biofilm is no longer a pure culture of the microbe. the biofilm culture was not incubated under the appropriate conditions. the microenvironments within a biofilm promote structural variation. A new drug is found to act by blocking the incorporation of subunits into sterol molecules for the cell membrane. Which statement is true? A. B. C. D. E. Only archaeal cells would be affected by this drug. Only biofilms would be affected by this drug. Most bacteria would be unaffected by this drug. A drug with this mechanism would be an excellent antibiotic. This kind of drug would destroy viruses only. 11. You need to determine if a pure culture of bacteria is gram-positive or gram-negative, but you've just spilled your only solution of crystal violet so you can't do a Gram stain. You decide to try a lysozyme treatment on a sample of each culture and then examine the samples under the microscope. The expected result is A. gram-positives will lyse and appears as debris; gram-negatives will lyse but more slowly. B. gram-positives will lyse and appears as debris; gram-negatives will be unaffected. C. gram-positives will lyse and appears as debris; gram-negatives will lose cellular morphology and appear as cocci. D. gram-negatives will lyse and appears as debris; gram-positives will lose cellular morphology and appear as cocci. E. gram-negatives will lyse and appears as debris; gram-positives will be unaffected. 12. Researchers studying the rigidity and flexibility of the cell envelope used chemotaxis to measure the ability of microbes to squeeze through tight spaces. E. coli, a gram-negative bacterium, was able to traverse narrower channels than B. subtilis, a gram-positive microbe, even though both cells are the same size when grown without restriction. E. coli has the more flexible cell envelope because A. B. C. D. E. 13. The process of sporangium formation and endospore maturation requires 6-8 hours. What is most likely to result if the temperature of the environment was raised to 100°C about 2 hours after the process started? A. B. C. D. E. 14. The chromosome in the endospore would likely carry mutations. The endospore would form more slowly and be heat resistant. The endospore would form properly but would be unable to germinate. The organism would be termed a hyperthermophile. The endospore would not form properly because it is not yet heat resistant. Archaea have been found in many microenvironments in the human body. Which of the following microenvironments is most likely to fit with the designation of Archaea as "extremophiles?" A. B. C. D. 15. lipopolysaccharide has no charge. it has fewer flagella. it has only a single membrane. there is less structural carbohydrate. there are fewer protein receptors. The inner ear can withstand increased pressure. The surface of the tongue has salt receptors. The gingiva and the gut are anaerobic. The temperature of the testes is less than 37°C. At present, the most accurate indicator of evolutionary relatedness among organisms is the A. size of the bacterial chromosome. B. C. D. E. 16. similarities of cell membrane proteins. sequence of the ribosomal small subunit RNA. size of the ribosomes. size of the periplasmic space. Serological analysis for bacterial identification typically involves using A. B. C. D. E. specific antibodies to the bacterial cell antigens. a microscope to determine cell morphology. the determination of guanine + cytosine base concentrations. methods to identify cell enzymes. the analysis of the appearance of colonies. 17. Which of the following bacteria is not closely related to the others? A. Salmonella enterica subsp. enterica B. Salmonella enterica subsp. indica C. Salmonella bongori D. Salmonella enterica subsp. Arizonae 18. Which of the following is mismatched? A. B. C. D. 19. Tenericutes - waxy, acid-fast cell walls Gracilicutes - gram-negative cell walls Mendosicutes - archaea cell walls Firmicutes - gram-positive cell walls A research laboratory that identifies the subspecies of bacterial isolates from a recent Salmonella epidemic would refer to Bergey's Manual of ______ Bacteriology for guidance in identification. A. B. C. D. Systematic Classical Evolutionary Determinative 20. A clinical laboratory that identifies the bacterial agents that cause human disease would refer to Bergey's Manual of ______ Bacteriology for guidance in identification. A. B. C. D. 21. The reference for bacterial descriptions and classifications is _____ Manual of Systematic Bacteriology. A. B. C. D. E. 22. Systematic Determinative Classical Evolutionary Leeuwenhoek's Lister's Koch's Bergey's Pasteur's Which of the following is not a phenotypic trait of bacteria? A. Cell shape B. Biochemical reactions C. rRNA sequence D. Nutrient requirements True / False Questions 23. Archaea do not have the typical peptidoglycan structure found in bacterial cell walls. TRUE Multiple Choice Questions 24. Which of the following is mismatched? A. Psychrophiles - adapted to very low temperatures B. Extreme halophiles - adapted to salty habitats C. Methanogens - convert CO2 and H2 into methane D. Hyperthermophiles - adapted to high temperatures E. Thermoplasmas - adapted to warm-blooded animal environments 25. Halobacterium salinarum lives in and requires a high salt concentration. This is an example of an archaeon described as a ______. A. B. C. D. 26. The function of bacterial endospores is A. B. C. D. 27. barophile halophile thermophile psychrophile to provide a protected site for photosynthesis. storage of excess cellular building blocks. protection of genetic material during harsh conditions. reproduction and growth. Chemical analysis of a bacterial cell detects dipicolinic acid. What is the identity of this structure? A. B. C. D. E. Nucleoid Cell wall Biofilm Capsule Endospore 28. Endospores are A. metabolically inactive. B. resistant to heat and chemical treatments. C. resistant to destruction by radiation. D. living structures. E. All of the choices are correct. 29. Bacterial endospores are produced by ______. A. Entamoeba B. Bacillus C. Mycoplasma D. Staphylococcus 30. All of the following occur during endospore germination except A. B. C. D. 31. All of the following structures contribute to the ability of pathogenic bacteria to cause disease except ______. A. B. C. D. E. 32. the cell grows out of its protein coats. binding of a small organic molecule to initiate germination. dehydration of the cell components. enzymes digest the endospore cortex. gram-negative outer membrane inclusions slime layer capsule fimbriae Magnetosomes are A. B. C. D. E. infoldings of the cell membrane. found in all bacteria and some archaea. responsible for the heat resistance of endospores. also termed metachromatic granules. composed of magnetic iron oxide particles. 33. Plasmids A. B. C. D. E. are found in all bacteria. are essential for survival. are located in microcompartments. cannot be passed between organisms. often carry genes controlling pathogenicity. True / False Questions 34. Endospores of certain bacterial species can enter tissues in the human body, germinate, and cause an infectious disease. TRUE 35. Boiling water (100°C) can normally destroy endospores. FALSE Multiple Choice Questions 36. All bacterial cells have ______. A. B. C. D. E. an S-layer flagella the ability to produce endospores capsules a chromosome 37. Which of the following bacterial structures is incorrectly matched with a function? A. Nucleoid - hereditary material B. Plasmids - contain genes essential for growth and metabolism C. Cytoplasm - dense, gelatinous solution D. Ribosomes - protein synthesis E. Inclusions - excess cell nutrients and materials 38. The site for ATP synthesis in bacterial cells is the ______. A. B. C. D. E. 39. The most immediate result of destruction of a cell's ribosomes would be that A. B. C. D. E. 40. material would not cross the cell membrane. the chromosome would unravel. protein synthesis would stop. holes would appear in the capsule. glycogen inclusions would form. The chromosome in bacteria and archaea A. B. C. D. 41. cell membrane mitochondrion cell wall microcompartment ribosome contains all the cell's plasmids. is located in the cell membrane. forms a single linear strand of DNA. is part of the nucleoid. The chemical components of ribosomes are proteins and ______. A. B. C. D. mRNA tRNA rRNA DNA