(Test Bank) Microbiology An Evolving Science

Slonczewski,Foster, 3

Biology

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3rd Edition

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Test Bank for Microbiology An Evolving Science, The downloadable file consists of 375 pages, and the total size of the file is 3.36 MB. Purchase now only for highly discounted price.

Author(s): Slonczewski, Foster

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MULTIPLE CHOICE 1. Viruses are: a. infectious agents that infect multi -cellular organisms b. noncellular particles that take over the metabolism of a cell to generate more virus particles c. pathogens that replicate in complex growth media d. cellular particles that belong to the archaea domain e. microbes that consist of lipid membrane enclosed genomes ANS: B DIF: Easy REF: 1.1 TOP: I.A | I.B MSC: Remembering 2. Analysis of DNA sequences reveals: a. the ancient convergence of two cell types, i.e., prokaryotes and eukaryotes b. prokaryotes and eukaryotes evolved from a common ancestral cell c. that bacteria share common ancestor with archaea, but not with eukarya d. prokaryotes are cells with a nucleus e. the genome of Haemophilus influenzae has about 2 billion base pairs ANS: B DIF: Easy REF: 1.1 TOP: I.A | I.B MSC: Remembering 3. Which of these groups are considered to be microbes but NOT considered to be ce lls? a. viruses d. protists b. bacteria e. filamentous fungi c. archaea ANS: A DIF: Easy REF: 1.1 TOP: I.A.i MSC: Remembering 4. A microbe is commonly defined as: a. a virus that requires a microscope to be seen b. a bacterium that requires a microscope to be seen c. a single-cellular prokaryote that requires a microscope to be seen d. a multicellular eukaryote that requires a microscope to be seen e. a living organism that requires a microscope to be seen ANS: E DIF: Easy REF: 1.1 TOP: I.A.i | I.A.ii MSC: Remembering 5. Which one of the following statements regarding microbial cells is NOT true? a. Microbial cells acquire food, gain energy to build themselves, and respond to environmental change. b. Most single-celled organisms require a microscope to render them visible , but some bacterial cells are large enough to be seen with naked eyes. c. Microbes function as individual entities. Test Bank for Microbiology An Evolving Science 3e by Joan Slonczewski, John Foster (All Cha pters) CHAPTER 1: Microbial Life: Origin and Discoveryd. Many microbes form complex multicellular assemblages. e. Viruses are not considered as microbial cells. ANS: C DIF: Easy REF: 1.1 TOP: I.A.i | I.A.ii MSC: Remembering 6. Which of the following statements is FALSE? a. A genome is the total genetic information contained in an organism’s chromosomal DNA. b. If a microbe’s genome includes genes for nitrogenase, that microbe probably can fix nitrogen. c. By comparing DNA sequences of different organisms, we can figure out how closely related they are. d. Fred Sanger developed the first applicable DNA sequencing method. e. Fred Sanger completed the sequences of Haemophilus influenzae . ANS: E DIF: Easy REF: 1.1 TOP: I.B MSC: Remembering 7. The first cellular genomes to be sequenced were those of: a. humans d. prions b. bacteria e. fungi c. viruses ANS: B DIF: Easy REF: 1.1 TOP: I.B.i MSC: Remembering 8. The environment of early Earth may have contained all of the following EXCEPT: a. ferrous iron d. oxygen b. methane e. hydrogen gas c. ammonia ANS: D DIF: Easy REF: Special Topic 1.1 TOP: II.D MSC: Remembering 9. The development of the theory of the “RNA world” resulted from the discovery of: a. archaea d. ribozymes b. prions e. endosymbionts c. bacteria ANS: D DIF: Medium REF: Special Topic 1.1 TOP: II.D MSC: Remembering 10. Which microbes may resemble those of the earliest life forms? a. archaea d. cyanobacteria b. photosynthetic algae e. protists c. viruses ANS: A DIF: Medium REF: Special Topic 1.1 TOP: II.D MSC: Remembering 11. Early metabolism may have been catalyzed by: a. DNA d. amino acids b. RNA e. carbohydrates c. protein ANS: B DIF: Medium REF: Special Topic 1.1 TOP: II.D MSC: Remembering 12. Which of the following diseases accounts for more than half of all human mortality? a. cardiovascular disease d. microbial disease b. cancer e. strokes c. accidents ANS: D DIF: Easy REF: 1.2 TOP: II.A MSC: Remembering 13. Which century is known as the golden age of microbiology? a. the seventeenth d. the twentieth b. the eighteenth e. the twenty -first c. the nineteenth ANS: C DIF: Easy REF: 1.2 TOP: II.A MSC: Remembering 14. All of the following have been found in mummies and tomb art EXCEPT: a. tuberculosis d. smallpox b. polio e. AIDS c. leprosy ANS: E DIF: Medium REF: 1.2 TOP: II.A.i MSC: Remembering 15. How did European invaders to North America kill much of the native population? a. tuberculosis d. HIV b. leprosy e. bubonic plague c. smallpox ANS: C DIF: Medium REF: 1.2 TOP: II.A.i MSC: Remembering 16. Nightingale: a. is better known as the founder of professional nursing b. was the first to use disinfectant to demonstrate the significance of aseptic technique c. developed the pie chart of mortality data during the Crimean War d. performed the first controlled experiment on the chemical conversion of matter, known today as chemotherapy e. all of the above ANS: A DIF: Easy REF: 1.2 TOP: II.A.ii MSC: Remembering 17. Who developed the concept of medical statistics? a. Francis Crick d. Louis Pasteur b. Florence Nightingale e. Alexander Fleming c. Edward Jenner ANS: B DIF: Easy REF: 1.2 TOP: II.A.ii MSC: Remembering 18. The first person to visualize individual microbes was: a. Antonie van Leeuwenhoek d. Lady Montagu b. Robert Hooke e. Edward Jenner c. Louis Pasteur ANS: A DIF: Easy REF: 1.2 TOP: II.B.ii MSC: Remembering 19. Which technique was developed to distinguish bacteria from human cells? a. Gram stain d. DNA sequencing b. electron microscopy e. polymerase chain reaction (PCR) c. X-ray diffraction ANS: A DIF: Medium REF: 1.2 TOP: II.B.ii MSC: Remembering 20. How is most sterilization performed for the controlled study of microbes? a. boiling d. autoclaving b. pasteurization e. irradiation c. filter sterilization ANS: D DIF: Medium REF: 1.2 TOP: II.C.iii.a MSC: Remembering 21. Microbes can shape human history via: a. lithotrophic activities d. production of cheese b. production of alcoholic beverages e. all of the above c. diseases that they cause ANS: E DIF: Medium REF: 1.2 TOP: II.A MSC: Understanding 22. Suppose Pasteur’s swan -necked flasks containing boiled broth became cloudy 24 hours after boiling. Which choice could best explain the turbidity or cloudiness in the broth without supporting spontaneous generation? a. Endospores in the broth survived boili ng and grew after the broth cooled. b. Contaminating organisms in the broth killed by boiling became alive again after the broth cooled. c. Chemicals in the broth came together to form living organisms. d. The broth allowed light to pass through it with less interference after boiling. e. Solid material in the broth dissolved during boiling. ANS: A DIF: Difficult REF: 1.2 TOP: II.C.ii.b MSC: Applying 23. Robert Koch’s greatest accomplishment in the field of medical bacteriology was with: a. Escherichia coli d. rabies b. Bacillus subtilis e. smallpox c. Mycobacterium tuberculosis ANS: C DIF: Medium REF: 1.3 TOP: III.B.i MSC: Remembering 24. The use of agar as the gelling agent in solid media was suggested by: a. Robert Koch d. Louis Pasteur b. Ignaz Semmelweis e. Richard Petri c. Angelina Hesse ANS: C DIF: Easy REF: 1.3 TOP: III.B.i.a MSC: Remembering 25. It took the advent of the PCR to detect the presence of the causative agent for which disease? a. anthrax d. rabies b. tuberculosis e. smallpox c. AIDS ANS: C DIF: Difficult REF: 1.3 TOP: III.B.ii MSC: Remembering 26. The word “ vaccination” is derived from the Latin word vacca , which means: a. inject d. cow b. smallpox e. pustule c. immunize ANS: D DIF: Easy REF: 1.3 TOP: III.C.i MSC: Remembering 27. What is the basis for the modern smallpox vaccine? a. chickenpox virus d. smallpox virus b. cowpox virus e. anthrax c. rabies virus ANS: B DIF: Easy REF: 1.3 TOP: III.C.i MSC: Remembering 28. Penic illin was first used to save the lives of many people during which war? a. Civil War d. World War I b. Korean War e. World War II c. Vietnam War ANS: E DIF: Easy REF: 1.3 TOP: III.C.iv MSC: Remembering 29. Which of the following can safely be ingested to fight bacterial infections? a. antiseptics d. chlorine b. disinfectants e. antibiotics c. phenol ANS: E DIF: Easy REF: 1.3 TOP: III.C.iv MSC: Remembering 30. All of the following are true about penicillin EXCEPT: a. It was discovered by Alexander Fleming. b. It was an accidental discovery. c. It is produced by a bacterium. d. It was the first antibiotic used by humans. e. It was purified by Florey and Chain. ANS: C DIF: Difficult REF: 1.3 TOP: III.C.iv MSC: Remembering 31. Which one of the following statements regarding viruses is FALSE? a. They are too small to be seen by a light microscope. b. They are ”filterable agents” that can pass through porcelain filters having a pore size that blocks microbes. c. Their genomes could be composed of DNA or RNA. d. They are smaller than viroids and prions. e. Viral particles, when pure enough, can be crystallized. ANS: D DIF: Medium REF: 1.3 TOP: III.D MSC: Remembering 32. You have isolated a bacterium that you believe to be the causative agent of a new disease in frogs. How would you test the third of Koch’s postulates? a. Determine the shape of the bacterial cells. b. Inject the bacteria into a healthy frog. c. Isolate the bacterium from a sick frog. d. Show that the bacterium is not present in healthy frogs. e. Grow a pure culture of the bacterium outside the frog. ANS: B DIF: Difficult REF: 1.3 TOP: III.B.ii MSC: Applying 33. How did Sergei Winogradsky grow lithotrophs? a. enrichment culture d. endosymbiosis b. organic media e. chain of infection c. pure culture ANS: A DIF: Easy REF: 1.4 TOP: IV.A.iii MSC: Remembering 34. Organisms that live symbiotically inside a larger organism are known as: a. organelles d. endosymbionts b. cyanobacteria e. chloroplasts c. mitochondria ANS: D DIF: Easy REF: 1.4 TOP: IV.B MSC: Remembering 35. Which group of microorganisms includes many that grow in extreme environments? a. algae d. archaea b. bacteria e. fungi c. protists ANS: D DIF: Easy REF: 1.4 TOP: IV.B MSC: Remembering 36. Carl Woese’ s discovery replaced the classification scheme of five kingdoms with a scheme of three: a. phyla d. orders b. domains e. genera c. classes ANS: B DIF: Easy REF: 1.5 TOP: V.D MSC: Remembering 37. The genetic expression machinery of archaea is most similar to: a. monera d. eukaryotes b. prokaryotes e. mitochondria c. bacteria ANS: D DIF: Medium REF: 1.5 TOP: V.D MSC: Remembering 38. In the three -domain model, the bacterial ancestor of mitochondria derives from ancient: a. fungi d. archaea b. cyanobacteria e. protists c. proteobacteria ANS: C DIF: Medium REF: 1.5 TOP: V.D MSC: Remembering 39. Which of the following organelles are thought to be of prokaryotic origin? a. chloroplast d. chloroplast and mitochondria b. mitochondria e. chloroplast and nucleus c. nucleus ANS: D DIF: Medium REF: 1.5 TOP: V.D MSC: Remembering 40. In the three -domain model, the bacterial ancestor of chloroplasts derives from ancient: a. fungi d. archaea b. cyanobacteria e. protists c. proteobacteria ANS: B DIF: Medium REF: 1.5 TOP: V.D MSC: Remembering 41. How are microbes classified today? a. comparative genomics d. protein sequencing b. microscopy e. 16S rRNA sequencing c. X-ray diffraction ANS: E DIF: Medium REF: 1.5 TOP: V.D MSC: Applying 42. What is used to focus the beam of electrons in an electron microscope? a. electromagnets d. X-ray diffraction b. condenser lens e. glass c. light rays ANS: A DIF: Easy REF: 1.6 TOP: VI.A.i MSC: Remembering 43. Peter Mitchell and Jennifer Moyle discovered the __________ theory in the 1960s. a. germplasm d. DNA synthesis b. evolution e. polymerase chain reaction c. chemiosmotic ANS: C DIF: Easy REF: 1.6 TOP: VI.B.ii MSC: Remembering 44. The X-ray diffraction studies by which of the following scientists concluded that DNA was a double helix? a. James Watson d. Maurice Wilkins b. Rosalind Franklin e. Kary Mullis c. Francis Crick ANS: B DIF: Easy REF: 1.6 TOP: VI.C MSC: Remembering 45. What type of analysis was used to discover the overall structure of the DNA double helix? a. microscopy d. DNA sequencing b. X-ray diffraction e. recombinant DNA c. polymerase chain reaction ANS: B DIF: Medium REF: 1.6 TOP: VI.C MSC: Remembering 46. Which scientist first discovered the process of transformation? a. Francis Crick d. Louis Pasteur b. Robert Koch e. Frederick Griffith c. Edward Jenner ANS: E DIF: Difficult REF: 1.6 TOP: VI.C MSC: Remembering 47. Taq polymerase formed the basis of a multibillion -dollar industry of: a. comparative genomics d. DNA amplification b. recombinant DNA e. DNA sequencing c. X-ray diffraction ANS: D DIF: Easy REF: 1.6 TOP: VI.C.ii MSC: Remembering 48. The Asilomar Conference was held to regulate and restrict the field of: a. recombinant DNA d. DNA amplification b. comparative genomics e. forensic microbiology c. DNA sequencing ANS: A DIF: Easy REF: 1.6 TOP: VI.C.iii MSC: Remembering 49. The study of and cause of disease in humans, animals, and plants is called: a. microbiology d. epidemiology b. phylogeny e. forensics c. genomics ANS: D DIF: Easy REF: 1.6 TOP: VI.D MSC: Remembering 50. The analysis of microbial strains as evidence in criminal investigations is known as: a. forensic microbiology d. classification b. recombinant DNA e. gene regulation c. comparative genomics ANS: A DIF: Easy REF: 1.6 TOP: VI.D MSC: Remembering SHORT ANSWER 1. What is the most recent evidence suggesting that all life on Earth shares a common ancestry? ANS: Many genomes have now been sequenced and those sequences are available in databases for comparison. This field is referred to as comparative genomics. Comparisons have revealed that there is a set of core genes shared by all organisms. DIF: Difficult REF: 1.1 TOP: I.B.i MSC: Understanding 2. How are prokaryotes and eukaryotes different? ANS: A prokaryote lacks a nucleus and membrane -bounded organelles, whereas a eukaryote has a nucleus and membrane -bounded organelles. DIF: Easy REF: 1.1 | 1.5 TOP: I.A.i | I.A.ii | V.C MSC: Remembering 3. How do microbes help in the extraction of minerals? ANS: Several lithotrophic bacteria help in the rapid oxidation of minerals, which generates strong acids that expedite the breakdown of mineral ore. Current ly, approximately 20% of the world’s copper, as well as some uranium and zinc, are produced by bacterial leaching. DIF: Medium REF: 1.2 TOP: II.A MSC: Understanding 4. Antonie van Leeuwenhoek worked as a cloth draper, inspecting the quality of cloth. Ho w did this lead to his interest in microscopy? ANS: Briefly, his work introduced him to magnifying lenses. He began the hobby of grinding lenses, ultimately making a microscope that enabled him to observe single -celled microbes. DIF: Medium REF: 1.2 TOP : II.B.ii MSC: Understanding 5. What was the major complaint about Lazzaro Spallanzani’s experiment to disprove spontaneous generation, and how did Louis Pasteur’s swan -neck flasks overcome this? ANS: Spallanz ani’s flasks were plugged so as not to let organisms accidentally enter the boiled medium. Opponents argued that no growth was observed simply due to the lack of oxygen. Pasteur’s swan -neck flasks did not allow organisms to enter the flask, but did allow oxyge n to enter. Growth was still not observed. DIF: Medium REF: 1.2 TOP: II.C.i MSC: Understanding 6. Describe the discoveries of Louis Pasteur while working with the French beer and wine manufacturers. ANS: Previously, it was believed that the conversion of grapes and grain to wine and beer was a spontaneous chemical process. He discovered that this fermentation was caused by living yeast, which did not require oxygen for growth. He also discovered that when the grapes or grain are contaminated with bacte ria instead of yeast, acetic acid is produced instead of alcohol. DIF: Medium REF: 1.2 TOP: II.C.ii MSC: Understanding 7. Describe the effects of three microbial diseases that have significantly affected human populations throughout history. ANS: Answ ers may vary. Some examples include bubonic plague, which killed one -third of Europe’s population in the fourteenth century; tuberculosis, which was common in the nineteenth century; AIDS, which affects many people today; and smallpox, which killed a large number of native North Americans. DIF: Medium REF: 1.2 TOP: II.A.i | II.A.ii MSC: Applying 8. Why did it take so long for humans to determine that microbes cause infectious diseases? ANS: Microbes are too small to be seen with the naked eye, so until microscopes were invented, humans did not know that microbes existed. Even after humans were awar e of the presence of microbes, they did not suspect them of causing disease until people such as Joseph Lister and Ignaz Semmelweis performed experiments that showed antiseptics decrease the incidence of infection. DIF: Difficult REF: 1.2 | 1.3 TOP: II.B.i | III.C.iii MSC: Understanding 9. Robert Koch’s postulates have not been used to prove HIV as the causative agent of AIDS. Why not? ANS: Answers may vary, but a major reason is that humans cannot be injected with HIV to see if they develop AIDS! DIF: Difficult REF: 1.3 TOP: III.B.ii MSC: Understanding 10. Define attenuation and describe some mechanisms used to attenuate pathogens. ANS: Attenuation results in a weakened organism that will not produce full -blown disease, but will generate immunity. Answers for mechanisms may vary. See discussion in textbook, Section 1.3, entitled “Immunization Prevents Disease.” DIF: Medium REF: 1.3 TOP: III.C.i | III.C.ii MSC: Understanding 11. What is the significance of the work of Ignaz Semmelweis and Joseph Lister? ANS: They showed that use of antiseptics on doctors’ hands and medical instruments drastically reduced the mortality rate of hospi tal patients. They made these observations before Robert Koch’s germ theory of disease. DIF: Medium REF: 1.3 TOP: III.C.iii MSC: Understanding 12. How would you use Robert Koch’s postulates to prove that a specific organism causes a new disease in mice? ANS: See Figure 1.18 in the textbook. (1) The suspected organism is found in all diseased mice, but is absent from healthy mice. (2) The suspected organism is isolated from the diseased mice and grown in pure culture. (3) When the suspected organism is introduced into a healthy mouse, the same disease occurs. (4) The same strain of microbe is obtained from the newly diseased mouse. DIF: Medium REF: 1.3 TOP: III.B.ii MSC: Applying 13. Explain why the organisms that were studied by Sergei Winogradsky could not be grown on Robert Koch’s plate media containing agar or gelatin. ANS: The organisms studied by Winogradsky were lithotrophs , which feed solely on inorganic substances. Koch’s plate media contained organic nutrient sources. DIF: Difficult REF: 1.4 TOP: IV.A.ii MSC: Understanding 14. Is it true that only culturable bacteria contribute to ecology? Explain your answer. ANS: No, this is not a true statement. It is estimated that barely 0.1% of microbial species can be cultured. The work of Winogradsky and later microbial ecologists showed that bacteria are necessary for geochemical cycling. Many of these organisms can’t be gro wn in pure culture on laboratory media, but can be grown in enrichment culture such as a Winogradsky column. DIF: Difficult REF: 1.4 TOP: IV.B MSC: Understanding 15. Define the term “endosymbiont” and give an example of an endosymbiotic relationship fou nd in nature. ANS: An endosymbiont is an organism living symbiotically inside a larger organism. Examples may vary, but include the following: Rhizobium in a leguminous plant; bioluminescent bacteria in the light organs of fish and squid; photosynthetic algae and coral. DIF: Medium REF: 1.4 TOP: IV.B MSC: Applying 16. Give two reasons why microbes have been difficult to classify. ANS: First, even with the use of light microscopes, only the basic shape of microbes can be determined, and many microbes have similar shapes even though they are very different in other ways. Second, microbes do not fit the classic definition of a species, which is a group of organisms that interbreed. Microbes typically reproduce asexually. When they do exchange genes, they may do so with distantly related species. DIF: Medium REF: 1.5 TOP: V.A.i | V.A.ii MSC: Understanding 17. Briefly explain the endosymbiosis theory and the evidence that supports it. ANS: The endosymbiosis theory proposes that mitochondria and chloroplasts evolved from bacteria that were engulfed by pre -eukaryotic cells, and that over time these endosymbiotic prokaryotic cells lost the ability to survive outside of the host cell but were ma intained as organelles. Evidence supporting the endosymbiosis theory includes the fact that mitochondria and chloroplasts possess circular DNA with similarity to modern bacteria. DIF: Difficult REF: 1.5 TOP: V.C MSC: Understanding 18. What were the cont ributions of Rosalind Franklin toward discovering the structure of DNA and why wasn’t she one of the recipients of the Nobel Prize for this discovery? ANS: She was an X -ray crystallographer who studied the structure of DNA. Her X -ray micrographs showed for the first time that DNA was a double helix. A colleague showed her micrographs to James Watson, who was also studying the structure of DNA. Watson and Francis Crick published their model of the structure of DNA in the journal Nature and denied that they had used Franklin’s micrographs. DIF: Medium REF: 1.6 TOP: VI.C.i MSC: Remembering 19. Briefly describe how the ultracentrifuge is used to determine the sizes of cellular macromolecules. ANS: The ultracentrifuge uses centrifugal forces to separate cell components. Theodor Svedberg calculated that the particle sizes could be determined based on the rate of sedimentation of the particles in an ultracentrifuge. DIF: Medium REF: 1.6 TOP: VI.B.ii MSC: Understanding 20. If you want to produce DNA polymerases like those used in polymerase chain reaction (PCR) for amplification of DNA, from which natural environment would you try to isolate the producers? ANS: Taq DNA polymerase used in PCR amplifi cation of DNA was extracted from Thermus aquaticus , a bacterium found in a hot spring in Yellowstone National Park. Since DNA polymerase has to survive many rounds of cycling to near -boiling temperatures, the most conducive environment for finding DNA poly merase, such as the enzymes used in PCR reactions, would be searching for microbes in an environment where the temperature is extremely high. DIF: Difficult REF: 1.6 TOP: VI.C.ii MSC: Applying CHAPTER 2: Observing the Microbial Cell MULTIPLE CHOICE 1. Who proved that stomach ulcers are caused by a bacterium? a. Hooke d. Jenner b. Marshall e. van Leeuwenhoek c. Gram ANS: B DIF: Easy REF: Introduction TOP: VI MSC: Remembering 2. The part of the human eye that is most involved in resolving an image is the: a. iris d. retina b. lens e. cornea c. optic nerve ANS: D DIF: Medium REF: 2.1 TOP: I.A MSC: Remembering 3. A ball -shaped microbe is referred to as a: a. bacillus d. strepto b. coccus e. spirochete c. vibrio ANS: B DIF: Easy REF: 2.1 TOP: I.C.ii.b MSC: Remembering 4. Resolution is the smallest distance by which two objects can be __________ and still be __________. a. magnified; seen d. distinguished; separated b. separated; distinguished e. magnified; distinguished c. magnified; separated ANS: B DIF: Medium REF: 2.1 TOP: I.A.i MSC: Understanding 5. 400 nm is equivalent to: a. 4.0 x 10-5 m d. 4.0 x 10-8 m b. 4.0 x 10-6 m e. 4.0 x 10-9 m c. 4.0 x 10-7 m ANS: C DIF: Medium REF: 2.1 TOP: I.A MSC: Applying 6. Which of these series arranges microbes from smallest to largest? a. virus → bacterium → red blood cell → paramecium b. virus → red blood cell → bacterium → paramecium c. bacterium → virus → paramecium → red blood cell d. bacterium → virus → red blood cell → paramecium e. paramecium → red blood cell → bacterium → virus ANS: A DIF: Difficult REF: 2.1 TOP: I.C MSC: Applying 7. The heating of water when exposed to light is primarily due to: a. reflection d. scattering b. refraction e. fluorescence c. absorption ANS: C DIF: Difficult REF: 2.2 TOP: II.B.i.a MSC: Remembering 8. Wavelength interference results in small observed objects (like bacteria) being surrounded by: a. a capsule d. a dark field b. a membrane e. a cell wall c. an Airy disk ANS: C DIF: Medium REF: 2.2 TOP: II.C MSC: Remembering 9. What is the most important property that enables a lens to magnify an image? a. absorption d. refraction b. fluorescence e. scattering c. reflection ANS: D DIF: Medium REF: 2.2 TOP: II.C MSC: Understanding 10. When two waves are out of phase by __________ wavelength, they produce destructive interference, canceling each other’s amplitude and resulting in contrast in the image. a. one-tenth of a d. one-half of a b. one-eighth of a e. one c. one-quarter of a ANS: D DIF: Difficult REF: 2.2 TOP: II.D MSC: Understanding 11. Increasing the refractive index of the medium between the object and the objective lens increases: a. refraction d. resolution b. reflection e. wavelength c. magnification ANS: D DIF: Difficult REF: 2.2 TOP: II.D MSC: Understanding 12. If a glass slide was submerged in a beaker of immersion oil, the slide would be: a. undetectable d. fluorescent b. brighter than its surroundings e. stained c. darker than its surroundings ANS: A DIF: Medium REF: 2.2 TOP: II.A.ii.a MSC: Applying 13. What would happen if a lens had the same refractive index as air? a. Light would not pass through the lens. b. The image would be magnified more than with a glass lens. c. The image would be magnified, but the resolution would be less than with a glass l ens. d. The image would be magnified, and the resolution would be greater than with a glass lens. e. The image would not be magnified. ANS: E DIF: Medium REF: 2.2 TOP: II.C MSC: Applying 14. The highest useful magnification for a light microscope is about: a. 100X d. 100,000X b. 1,000X e. 1,000,000X c. 10,000X ANS: C DIF: Medium REF: 2.2 TOP: II.D MSC: Applying 15. A(n) __________ acts to vary the diameter of the light column in a light microscope. a. condenser d. diaphragm b. objective e. lens c. ocular ANS: D DIF: Easy REF: 2.3 TOP: III.B.i MSC: Remembering 16. Which of these arranges the steps of the Gram stain into the correct order? a. iodine → crystal violet → decolorizer → safranin b. safranin → decolorizer → crystal violet → iodine c. crystal violet → decolorizer → iodine → safranin d. crystal violet → decolorizer → safranin → iodine e. crystal violet → iodine → decolorizer → safranin ANS: E DIF: Medium REF: 2.3 TOP: III.E.ii.a MSC: Remembering 17. When Gram stained, most eukaryotes appear: a. colorless d. green b. purple e. black c. pink ANS: C DIF: Medium REF: 2.3 TOP: III.E.ii.a MSC: Remembering 18. Malachite green is commonly used to stain: a. eukaryotic cells d. bacterial endospores b. Gram -negative cells e. acid-fast cells c. Gram -positive cells ANS: D DIF: Medium REF: 2.3 TOP: III.E.ii.c MSC: Remembering 19. As lens strength increases, the light cone __________ and the lens must be __________ the object. a. narrows; nearer to d. widens; farther from b. narrows; farther from e. widens; touching c. widens; nearer to ANS: C DIF: Medium REF: 2.3 TOP: III.A MSC: Understanding 20. Staining helps to visualize bacteria by: a. increasing the size of the cells