Microbiology: Bacteria and View Feedback

Microbiology: Bacteria and View Feedback

Question 1 Microbes are not responsible for ________.

  • synthesis of acetone and alcohol
  • breaking down wastes
  • synthesis of vitamins
  • antibody production
  • oxygen generation via photosynthesis

Question 2 The cell theory states that ________ are made up of cells.

  • protozoa
  • archaea
  • plants
  • all living things
  • animals

Question 3 In Pasteur’s swan-neck flask experiment, the importance of the S-shaped curves in the flasks was twofold. The curves allowed entry of air, and yet excluded ________.

  • oxygen
  • nutrients
  • airborne bacteria
  • broth
  • heat

Question 4 Pasteurization was first developed to kill ________ in wine.

endospore-producing bacteria

  • all bacteria
  • disease-causing bacteria
  • antibiotic-producing bacteria
  • spoilage bacteria

Question 5 Robert Koch’s studies on Bacillus anthracis established a sequence of experimental steps to prove that microbes ________.
can be altered to produce products such as human insulin

  • degrade toxic wastes
  • control insect pests
  • recycle elements such as nitrogen
  • cause disease

Question 6 An exposure to ________ protects against infection with smallpox.

  • antibody
  • chemotherapy
  • penicillin
  • normal microbiota
  • cowpox

Question 7 Ehrlich searched for a/an ________. This is a chemical that would hunt down and destroy a pathogen without harming the infected host.

  • animalcule
  • vital force
  • vaccine
  • magic bullet
  • pathogen

Question 8 How would you recognize an antibiotic-producing soil bacterium on a plate crowded with other bacteria? The bacterial colony producing the antibiotic would be ________.

  • characterized by pseudopods
  • surrounded by a clear area
  • visible as masses called mycelia
  • pigmented
  • star-shaped

Question 9 The usefulness of antibiotics is hampered by ________.

  • the emergence of antibiotic-resistant bacteria
  • the limited types of antibiotic available
  • their inability to kill specific bacteria
  • difficulties encountered in mass production
  • an antibiotic’s lack of specificity for bacterial versus animal cells

Question 10 All life can be classified into three domains ________.

  • Eukaryotes, Prokaryotes, Viruses
  • Bacteria, Archaea, Eukarya
  • Carnivores, Herbivores, Omnivores
  • Animalae, Plantae, Microbes
  • Bacteria, Fungi, Protozoa

Question 11 Which of the following is characteristic of bacteria?

  • Bacteria have DNA or RNA, but not both.
  • Bacteria reproduce by a cell division process known as mitosis.
  • Bacteria live in extreme environments, including pH, temperature, and pressure extremes.
  • Bacteria lack a membrane-bound nucleus.
  • Bacteria have cellulose or chitin in their cell walls.

Question 12 All of the following are eukaryotes except ________.

  • bacteria
  • fungi
  • helminths
  • algae
  • protozoa

Question 13 A new microorganism has been isolated from hot springs in Yellowstone National Park. It consists of single cells, which appear to lack a nucleus. Chemical analysis shows the presence of both DNA and RNA in the cytoplasm and pseudomurein in the cell wall. In which of the following groups will this organism be classified?

  • Plants
  • Archaea
  • Bacteria
  • Protists
  • Fungi

Question 14 Arsenic is a relatively common hazardous waste generated by smelting processes and can contaminate soil and water surrounding smelting facilities. A bioprocess using naturally occurring bacteria to remove arsenic has been developed. This process is an example of ________.

  • nitrogen fixation
  • bioremediation
  • fermentation
  • gene therapy
  • genetic engineering

Question 15 Placing the DNA from an animal cell into the genome of a bacterium will allow the bacterium to produce an animal product. This new piece of DNA is referred to as ________.

  • conjugation product
  • the genetic code
  • the hereditary material
  • an enzyme
  • recombinant DNA

Question 16 Which of the following properties are true of both bacteria and viruses? Both are surrounded by a protein coat.

  • Both use a molecule of nucleic acid to determine heredity.
  • Both contain DNA and RNA.
  • Both have cell walls composed of peptidoglycan.
  • Both can replicate independently.

Question 17 Which is not a characteristic of the normal microbiota?

  • may benefit the human host
  • live on our bodies
  • regularly associated with disease symptoms
  • often are called the normal flora
  • live within our bodies

Question 18 Increased human exposure to new and unusual infectious agents in areas that are undergoing ecologic changes accounts for the ________.

  • emergence of new infectious disease
  • increased incidence of smallpox
  • development of antibiotic-resistant bacteria
  • debate over the use of chemical pesticides
  • lack of natural resistance to infectious disease

Question 19 Mad cow disease is caused by a prion, which is an infectious ________.

  • piece of RNA
  • protein
  • lipid
  • sugar
  • piece of DNA

Question 20 Overuse and misuse of antibiotics has ________.

  • selected for antibiotic-resistant strains of bacteria and increased their frequency in both the hospital environment and the community
  • directly caused mutations in bacteria that enable them to destroy the antibiotic
  • caused bacteria to become resistant to household disinfectants such as chlorine bleach
  • caused bacteria to acquire virulence factors and become more deadly
  • caused viruses to become resistant to a variety of antibiotics

Question 21 The first observations of bacteria were made by ________.

  • Hooke
  • Van Leeuwenhoek
  • Pasteur
  • Needham
  • Van Leeuwenhoek was the first person able to observe bacteria through the microscopes he assembled. These microscopes were able to magnify 300x.

Question 22 All of the following scientists performed experiments that supported the theory of biogenesis except ________.

  • Redi
  • Virchow
  • Needham
  • Pasteur

Question 23 Working with the French wine industry, Louis Pasteur developed a process that ________.

  • sterilizes the wine
  • promotes the growth of yeast during the wine-making process
  • removes spoilage microorganisms from wine
  • improves the nutritional value of wine

Question 24 West Nile virus is transmitted to humans by ________.

  • contaminated food
  • ticks
  • mosquitoes
  • fleas

Question 25 All of the following are products produced naturally by microorganisms except which one?

  • butyl alcohol
  • silk
  • ethyl alcohol
  • acetone

Question 26 Which of the following scientists and their discoveries is not correctly matched?

  • Jenner; vaccination
  • Koch; germ theory of disease
  • Ehrlich; chemotherapy
  • Lister; antibiotics

Question 27 Which of the following is a scientific name?

  • Philadelphia fever
  • Legionnaires’ bacterium
  • Legionnaires’ disease
  • Legionella pneumophila

Question 28 Which of the following fields of study and its example are not correctly matched?

  • mycology; study of athlete’s foot
  • immunology; study of vaccines
  • bacteriology; study of E. coli O157:H7
  • parasitology; study of HIV

Question 29 In the scientific name, Escherichia coli, Escherichia is the ________.

  • class
  • species
  • genus
  • family

Question 30 Which of the following types of microorganism and its description is not correctly matched?

  • protozoa; small animals
  • helminthes; multicellular animals
  • bacteria; prokaryotic
  • fungi; eukaryotic

Question 31 Which of the following is not a characteristic of Bacteria?

  • They reproduce by a process called binary fission.
  • Cell walls are composed of peptidoglycan.
  • All are unicellular.
  • All are pathogenic.

Question 32 Which of the following does not belong with the others?

  • plants
  • bacteria
  • fungi
  • animals

Question 33 The laboratory and medical procedures employed to prevent microbial contamination are called ________.

  • aseptic techniques
  • Koch’s postulates
  • sterilization
  • bioremediation

Question 34 All of the following are examples of biotechnology except ________.

  • antibiotic production by bacteria
  • bacteria that cause disease
  • bread making with bacteria and fungi
  • enzyme production by bacteria and fungi

Question 35 Avian influenza has not yet become widespread among humans because ________.

  • it infects only birds
  • when humans are infected, they do not get sick
  • it is not readily transmitted from human to human
  • humans are vaccinated against avian influenza

Question 36 Emerging infectious diseases can be due to ________.

  • deforestation and earthquake
  • changes or mutations in existing organisms
  • humans moving to previously uninhabited areas
  • all of the above

Question 37 Which one of the following is an example of bioremediation?

  • use of Pseudomonas to remove uranium from soil at weapons depots
  • use of Sacccharomycescerevisiae to make wine
  • use of Bacillus thuringiensis to kill crop-eating insects
  • use of cowpox virus to vaccinate against smallpox

Question 38 Which of the following processes are beneficial activities of microorganisms?

  • recycling elements in the environment
  • decomposing sewage
  • producing foods and chemicals
  • all of the above

Question 39 Which of the following best describes the introduction of a human gene into bacteria to induce the bacteria to produce the

human protein?

  • bioremediation
  • genomics
  • recombinant DNA technology
  • gene therapy

Question 40 Which of the following statements about bacteria is not true?

  • The only good bacterium is a dead bacterium.
  • Everyone has bacteria in and on the body.
  • Bacteria are used to make some foods.
  • Bacteria are essential to the presence of life on Earth.

Question 41 Robert Hooke’s observation of the individual units in thin layers of cork tissue led to the development of ________ theory.

Answer:cell

Question 42 Lister knew that carbolic acid (phenol) kills bacteria. He used it as the first ________.

  • Answer:disinfectant

Question 43 The protection from disease provided by vaccination is called ________.

Answer:immunity

Question 44 The ________ are unicellular, eukaryotic microbes that move by pseudopods, flagella, or cilia.

  • Answer:protozoa

Question 45 _______ involves the ability afforded by genetic engineering to insert a missing gene or replace a defective gene in a human cell.

  • Answer:recombinant dna (Gene therapy)

Question 46 Microbes are not responsible for ________.

  • synthesis of vitamins
  • breaking down wastes
  • oxygen generation via photosynthesis
  • antibody production
  • synthesis of acetone and alcohol

Question 47 An exposure to ________ protects against infection with smallpox.

  • penicillin
  • normal microbiota
  • antibody
  • cowpox
  • chemotherapy

Question 48 All life can be classified into three domains ________.

  • Eukaryotes, Prokaryotes, Viruses
  • Carnivores, Herbivores, Omnivores
  • Bacteria, Fungi, Protozoa
  • Bacteria, Archaea, Eukarya
  • Animalae, Plantae, Microbes

Question 49 Which of the following properties are true of both bacteria and viruses?

  • Both can replicate independently.
  • Both use a molecule of nucleic acid to determine heredity.
  • Both contain DNA and RNA.
  • Both have cell walls composed of peptidoglycan.
  • Both are surrounded by a protein coat.

Question 50 Mad cow disease is caused by a prion, which is an infectious ________.

  • sugar
  • piece of RNA
  • protein
  • lipid
  • piece of DNA

Question 51 Which of the following is a scientific name?

  • Legionnaires’ bacterium
  • Legionella pneumophila
  • Legionnaires’ disease
  • Philadelphia fever

Question 52 Which of the following fields of study and its example are not correctly matched?

  • immunology; study of vaccines
  • parasitology; study of HIV
  • bacteriology; study of E. oli O157:H7
  • mycology; study of athlete’s foot

Question 53 In the scientific name, Escherichia coli, Escherichia is the ________.

  • species
  • class
  • family
  • genus

Question 54 Which of the following types of microorganism and its description is not correctly matched?

  • bacteria; prokaryotic
  • protozoa; small animals
  • helminthes; multicellular animals
  • fungi; eukaryotic

Question 55 All of the following are examples of biotechnology except ________.

  • bacteria that cause disease
  • antibiotic production by bacteria
  • enzyme production by bacteria and fungi
  • bread making with bacteria and fungi

Question 56 Examples of fungi include the yeasts, molds, and mushrooms.

  • True
  • False

Question 57 Flagella are appendages that allow locomotion in bacteria.

  • True
  • False

Question 58 E. coli O157:H7 is part of the normal microbiota in the human large intestine.

  • True
  • False

Question 59 The avian influenza A virus is transmitted only between birds.

  • True
  • False

Question 60 E. coli O157:H7 is part of the normal microbiota in the human large intestine.

  • True
  • False

Question 61 Which of the following is the most convenient and appropriate unit for expressing the size of an average bacterial cell?

  • millimeter
  • micrometer
  • centimeter
  • nanometer

Question 62 A decolorizer is used to ________.

  • stain gram-negative cells
  • selectively remove stain from cells
  • wash slides
  • clean off excess stain

Question 63 A simple stain ________.

  • requires two steps: a staining step and a decolorization step
  • readily differentiates bacterial groups
  • allows observation of bacterial motility
  • improves visibility of bacterial cells by increasing the contrast between the cell and the background

Question 64 All of the following are accomplished by “fixing” a smear except ________.

  • cells are attached to the slide so they ‘will not wash
  • off
  • cells are killed
  • cell structures are differentiated
  • cellular structures are preserved with minimal distortion

Question 65 All of the following are visible through a compound light microscope except ________.

  • 5-? m nucleus
  • 0. 02-? m ribosome
  • 10- ? m human cell
  • 2-? m bacterial cell

Question 66 If you stained a bacterial smear with a blue basic stain, then counterstained with a red acidic stain, you would expect to see ________.

  • blue cells against a red background
  • red acid-fast cells
  • red and blue cells
  • red cells against a blue background

Question 67 If you use a compound light microscope, a 2-? m bacterial cell is best seen at which magnification?

  • 1000x
  • 400x
  • 10x
  • 100x

Question 68 Immersion oil is used with the 100x objective lens of the compound light microscope to ________.

  • prevent the loss of light due to refraction
  • condense the light
  • provide additional magnification
  • separate the light into different wavelengths

Question 69 In a negative stain, gram-negative bacteria will be ________.

  • colorless
  • green
  • red
  • purple

Question 70 In the decolorizing step of the acid-fast stain, which reagent is used?

  • acetone-alcohol
  • carbol fuchsin
  • methylene blue
  • acid-alcohol

Question 71 In the decolorizing step of the Gram stain, which reagent is used?

  • acetone-alcohol
  • iodine
  • malachite green
  • crystal violet

Question 72 Place these structures of the compound light microscope in the order that light passes through them on the way to the observer’s eyes: (1) condenser, (2) ocular lens, (3) illuminator, (4) specimen, (5) objective lens.

  • 3-1-4-5-2
  • 3-4-1-5-2
  • 3-1-5-4-2
  • 2-1-4-3-5

Question 73 The purpose of the counterstain in the Gram stain is to ________.

  • make gram-positive cells visible
  • make gram-negative cells visible
  • decolorize gram-negative cells
  • decolorize gram-positive cells

Question 74 What metric unit would be most appropriate and convenient for expressing the size of most viruses?

  • nanometer
  • micrometer
  • millimeter
  • centimeter
  • Question 75 Which of the following is not a modification of a compound microscope?
  • brightfield microscope
  • fluorescent microscope
  • electron microscope
  • darkfield microscope

Question 76 Which of the following is the same size as a 1-? m bacterial cell?

  • 10- nm (diameter) cytoskeleton filament
  • 0. 1- nm (diameter) molecule of DNA
  • 1000- nm (length) mitochondrion
  • 100- nm (diameter) lysosome

Question 77 Which of the following measurements equals 1 mm?

  • 0. 01 m
  • 10 cm
  • 1000 ? m
  • 001 ? m

Question 78 Which of the following types of microscopy provides a three-dimensional image of the surface of viruses and bacterial cells?

  • fluorescence microscopy
  • phase-contrast microscopy
  • transmission electron microscopy
  • brightfield microscopy
  • scanning electron microscopy

Question 79 You are viewing a eukaryotic cell using a total magnification of 400x. If your ocular lens is a 10x lens, what is the magnification of the objective lens you are using?

  • 4x
  • 400x
  • 40x
  • 100x

Question 80 You see purple bacterial cells in a gram-stained smear from your tooth scrapings. You can conclude that ________.

  • your cells are gram-positive
  • there are bacteria on your teeth
  • human cells are gram-positive
  • gram-positive bacteria cause tooth decay

Question 81 Acid-fast Mycobacteria differ from non-acid-fast bacteria by the presence of ________.

  • flagella
  • peptidoglycan
  • endospores
  • capsules
  • mycolic acid in their cell wall

Question 82 All of the following are true for both TEM and SEM except

  • The microscope is focused using electromagnetic lenses.
  • Both can be used to view specimens smaller than 0. 2 micrometers.
  • The illuminating source is an electron beam.
  • The specimen must be sectioned before viewing.
  • Black-and-white images are produced.

Question 83 Bacterial cells have an overall negative charge on their surface. If a bacterial smear is stained by a pink, acidic, water-soluble stain and then washed with water, which of the following describes the result?

  • pink cells
  • unstained cells in a pink background
  • pink cells in a pink background
  • purple cells
  • unstained cells with no background

Question 84 In a negative staining procedure, the bacterial cells would be ________.

  • stained in an unstained background
  • the same color as the background and thus not easily observed
  • brightly colored in a contrasting background
  • attracted to the dye used in the staining procedure
  • unstained in a colored background

Question 85 In the capsule stain using India ink, capsules are distinguished as ________ surrounding cells.

  • green shadows
  • clear halos
  • pink circles
  • purple rims
  • blue extensions

Question 86 In the Gram stain, crystal violet is the ________.

  • counterstain
  • primary stain
  • fixative
  • decolorizing agent
  • mordant

Question 87 In the Gram stain, crystal violet remains in gram-positive cells after treatment with alcohol because crystal violet-iodine (CV-I) complexes are trapped ________.

  • in mycolic acid
  • by endospores
  • in thick layers of peptidoglycan
  • by flagella
  • in the outer membrane

Question 88 In the Gram stain, if the decolorizing step is deleted, gram-negative cells will appear ________ at the completion of the staining procedure.

  • pink
  • blue
  • purple
  • unstained
  • green

Question 89 In the Gram-stain procedure, a clear oval in the center of a cell could indicate ________.

  • lack of the central nucleoid
  • capsule
  • the unstained bacterial chromosome
  • presence of an endospore
  • an unstained nucleus

Question 90 Resolution is great when using an electron microscope because the ________ of the electron beam is much shorter than that of visible light.

  • penetration
  • absorption
  • frequency
  • reflection
  • wavelength

Question 91 The ________ charge of a basic dye adheres to the ________ charge of bacterial cell surfaces.

  • positive; …… basic
  • positive; …… acidic
  • negative; …… positive
  • positive; …… negative
  • negative; …… acidic

Question 92 Which is common to the Gram stain and acid-fast stain?

  • fixation of the smear before staining
  • use of iodine as a mordant
  • use of steam for stain penetration
  • use of methylene blue as a counterstain
  • use of acid alcohol for decolorizing

Question 93 Which of the following kinds of microscopy would be most appropriate for viewing the shape and arrangement of pili or fimbriae on the surface of a bacterial cell?

  • transmission electron microscopy
  • brightfield microscopy
  • phase-contrast microscopy
  • darkfield microscopy
  • scanning electron microscopy

Question 94 Which of the following types of microscopy can be used to specifically identify pathogens (such as Mycobacterium tuberculosis or Rabies virus) in specimens?

  • transmission electron
  • darkfield
  • brightfield
  • fluorescence
  • phase-contrast

Question 95 Which of the following types of microscopy is most useful for viewing the internal structures of unstained specimens?

  • confocal
  • brightfield
  • phase-contrast
  • electron
  • fluorescence

Question 96 Which of the following types of microscopy is used to study the structure of the slimy accumulation of bacteria on an IV catheter tip?

  • phase-contrast
  • atomic force
  • scanning acoustic
  • scanning electron
  • confocal

Question 97 Which type of light microscopy is used to visualize stained specimens?

  • brightfield
  • phase-contrast
  • binocular
  • darkfield
  • compound

Question 98 Which type of microscope uses a metal and diamond probe that is gently forced down along the surface of a specimen?

  • scanning tunneling
  • atomic force
  • transmission electron
  • confocal
  • scanning electron

Question 99 You are viewing a sputum smear that has been stained with an acid-fast stain. On this smear you see 5-? – long red cells. You can conclude that ________.

  • human cells are acid-fast
  • the normal microbiota are acid-fast
  • the normal microbiota are gram-negative
  • there are acid-fast bacteria in the specimen
  • there are no acid-fast bacteria in the specimen

Question 100 Your lab partner tells you the bacteria are moving in his Gram-stained smear. You can conclude that ________.

  • he did a flagella stain, not a Gram stain
  • he didn’t fix the smear
  • the bacteria are gram negative
  • the bacteria are chemotactic
  • the bacteria have capsules

Question 101 A counterstain may be used to improve the bonding between a primary stain and the specimen.

  • True
  • False

Question 102 Bacterial motility and flagellar movement can readily be viewed using transmission electron microscopy.

  • True
  • False

Question 103 Bacterial smears must be heat-fixed before all staining procedures.

  • True
  • False

Question 104 Fluorescent dye-labeled antibodies would allow specific recognition of one bacterium in a mixed culture of bacteria.

  • True
  • False

Question 105 Gram-positive bacteria retain the primary stain after decolorizing with ethanol-acetone.

  • True
  • False

Question 106 Immersion oil acts to decrease refraction of light rays and thus increase resolution.

  • True
  • False

Question 107 Magnification is the quality of the microscope that allows one to distinguish between two points that are very close together.

  • True
  • False

Question 108 Phase-contrast microscopy is an especially useful type of microscopy because it permits detailed examination of internal structures in living microorganisms.

  • True
  • False

Question 109 Stains used in electron microscopy increase the contrast between specimen and background by colorizing the internal structures differently.

  • True
  • False

Question 110 The Gram stain is important in medical microbiology because the results help physicians select appropriate antibiotics for treatment.

  • True
  • False

Question 111 Which of the following is not a functionally analogous pair?

  • peptidoglycan; cellulose
  • pili; centrioles
  • circular bacterial chromosome; -linear eukaryotic chromosomes
  • 70S ribosomes; 80S ribosomes
  • bacterial flagella; 9 + 2 flagella

Question 112 Polyphosphate (volutin), carboxysomes, and magnetosomes are examples of ________.

  • chloroplasts
  • capsules
  • fimbriae
  • inclusion bodies
  • mesosomes

Question 113 The antibiotic polymyxin B combines with phospholipids. This will cause ________.

  • binary fission
  • sporulation
  • stoppage of protein synthesis
  • loss of motility
  • leakage of cell contents

Question 114 Chemotaxis refers to the ability of microorganisms to ________.

  • survive under adverse conditions
  • move toward or away from chemical stimuli
  • attach to solid surfaces
  • move in a wavelike motion
  • escape phagocytosis

Question 115 All of the following are found in the cell walls of gram-positive bacteria except ________.

  • teichoic acid
  • peptidoglycan
  • N-acetylglucosamine
  • lipoteichoic acid
  • lipid

Question 116 Gram-negative cells contain a periplasmic space that is ________.
abundant in photosynthetic pigments

  • a site of endocytosis
  • the site of protein synthesis
  • rich in degradative enzymes
  • filled with lysozyme

Question 117 All of the following are true of the gram-negative outer membrane except:

  • It is a part of the gram-negative cell wall.
  • It has polysaccharide antigens that are useful in bacterial identification.
  • It contains lipopolysaccharide.
  • It contains lipids also known as endotoxin.
  • It contains enzymes for energy synthesis.

Question 118 The plasma membrane is considered a barrier to the environment because ________.

  • no molecules may pass through it
  • it is a rigid structure
  • the membrane is the outermost structure of the cell
  • it controls the passage of molecules into the cell
  • only water and small molecules may penetrate the membrane

Question 119 Which of the following is a likely outcome, based on the unique cell structure of members of the genus Mycoplasma?

  • Mycoplasma species are susceptible to penicillin.
  • Mycoplasma species can release endotoxins when they lyse.
  • Mycoplasma species usually stain gram-positive.
  • Mycoplasma species have very flexible cells that can pass through bacteriologic filters.
  • Mycoplasma species are susceptible to disruption by lysozymes.

Question 120 A population of bacterial cells has been placed in a very nutrient-poor environment with extremely low concentrations of sugars and amino acids. Which kind of membrane transport becomes crucial in this environment? facilitated diffusion

  • active transport
  • pinocytosis
  • osmosis
  • simple diffusion

Question 121 What will occur if a bacterial cell with a weakened or damaged cell wall is placed in pure water?

  • The cell will form a new cell wall.
  • The cell will swell and burst.
  • The cell will shrink.
  • The cell will form endospores.
  • The cell will remain the same size.

Question 122 Which of the following processes occurs in bacterial plasma membranes, but not in eukaryotic plasma membranes?

  • RNA synthesis
  • protein synthesis
  • active transport
  • ATP synthesis
  • facilitated diffusion

Question 123 Why is penicillin selectively toxic to bacterial cells but harmless to human cells?

  • Penicillin specifically weakens peptidoglycan, which is found only in bacterial cells.
  • Human cells actively transport penicillin out of the cell.
  • The glycocalyx of an animal cell provides a barrier through which penicillin cannot pass.
  • Penicillin is inactivated within lysosomes of human cells.
  • Penicillin is rapidly metabolized and destroyed by human cells.

Question 124 Bacillus anthracis causes the deadly disease anthrax. Organisms of the genus Bacillus may form endospores. This bacterium would be suitable for biological warfare because endospores ________.

  • have a high concentration of calcium ions
  • are centrally located within the bacterial cells
  • are difficult to stain
  • are multilayered structures
  • are resistant to high temperatures, UV light, and desiccation

Question 125 Assume you are growing a bacterial culture in a glucose medium. Your lab partner adds more glucose in hopes of speeding up the experiment. The bacteria suddenly die. The best explanation for this result is that ________.

  • the bacteria could not use glucose
  • the cells underwent sporulation
  • osmotic lysis occurred
  • the cells plasmolyzed
  • glucose is toxic to bacteria

Question 126 The nuclear area of the bacterial cell ________.

  • contains the bacterial chromosome
  • is connected to the endoplasmic reticulum
  • is enclosed in a nuclear membrane
  • has abundant histone proteins
  • contains many linear chromosomes

Question 127 A eukaryotic cell can ingest a prokaryotic cell by ________.

  • active transport
  • pinocytosis
  • osmosis
  • phagocytosis
  • digestive vacuolization

Question 128 Which of the following pairs is mismatched?

  • Golgi complex; secretion
  • mitochondria; ATP production
  • ribosomes; storage
  • endoplasmic reticulum; internal transport
  • lysosome; digestive enzymes

Question 129 Which of the following is not a structure of prokaryotic cells?

  • chloroplast
  • flagella
  • capsule
  • ribosome
  • chromosome

Question 130 With a light microscope, which of the following would allow discrimination between eukaryotes and prokaryotes?

  • observation of photosynthetic pigment
  • observation of the ribosomes
  • observation of nuclei
  • observation of the plasma membrane
  • observation of flagella

Question 131 You have isolated a cell with a peptidoglycan cell wall. What other structure can you safely assume the cell has?

  • a nucleus
  • a plasma membrane
  • a mitochondrion
  • a chloroplast

Question 132 You have isolated a cell that lacks a membrane-enclosed nucleus. You expect to find all of the following except which one?

  • a ribosome
  • a chromosome
  • a lysosome
  • peptidoglycan

Question 133 Spherical shaped bacteria that divide and remain attached in chainlike patterns are called ________.

  • tetrads
  • staphylococci
  • streptococci
  • spirochetes

Question 134 All of the following statements provide evidence for the endosymbiotic theory except:

  • The ribosomes contained within mitochondria and chloroplasts are very similar to prokaryotic ribosomes.
  • Mitochondria and chloroplasts contain circular DNA, similar to the DNA in prokaryotes.
  • The same antibiotics that inhibit protein synthesis in prokaryotes also inhibit protein synthesis within mitochondria and chloroplasts.
  • Prokaryotes contain peptidoglycan in their cell walls.

Question 135 Which of the following statements about a gram-negative cell wall is not true?

  • It has teichoic acids.
  • It includes a thin layer of peptidoglycan.
  • It contains endotoxin.
  • It maintains the shape of the cell.

Question 136 Which of the following processes requires energy?

  • active transport
  • osmosis
  • facilitated diffusion
  • simple diffusion

Question 137 Which of the following bacterial structures are necessary for chemotaxis?

  • metachromatic granules
  • plasmids
  • flagella
  • capsules

Question 138 Which of the following statements is true?

  • Endospores are extremely durable structures that can survive high temperatures.
  • One bacterial cell produces many endospores.
  • Endospores are reproductive structures.
  • Endospores allow a cell to attach to solid surfaces and to surfaces within the host.

Question 139 Which one of the following pairs is incorrectlymatched?

  • centrioles; cell division
  • lysosomes; secretion
  • Golgi complex; sorting proteins
  • mitochondrion; cellular respiration

Question 140 A “9+2 array” of microtubules is found within ________.

  • mitochondria
  • plant cell walls
  • ribosomes
  • eukaryotic flagella and cilia

Question 141 Which of the following eukaryotic cells do not contain a cell wall?

  • animals
  • algae
  • plants
  • fungi

Question 142 In a prokaryotic cell, all of the following are functions of the glycocalyx except ________.

  • protection from phagocytosis
  • attachment to environmental surface
  • movement
  • protection against dehydration

Question 143 Which of the following membrane transport mechanisms is found in eukaryotic cells, but not in prokaryotic cells?

  • endocytosis
  • osmosis
  • facilitated diffusion
  • active transport

Question 144 You are growing a bacterial culture in a medium containing the amino acid aspartic acid. You observe that the cells can take in the aspartic acid if glucose is present. In the absence of glucose, the cells do not take in any aspartic acid. The best explanation for this result is that aspartic acid enters the cells by ________.

  • active transport
  • osmosis
  • simple diffusion
  • facilitated diffusion

Question 145 The nucleus of a eukaryotic cell differs from the nucleoid of a prokaryotic cell in all of the following ways except:

  • The prokaryotic nucleoid contains a single circular chromosome, while the eukaryotic nucleus contains ultiple linear chromosomes.
  • The eukaryotic nucleus is surrounded by a nuclear envelope. There is no envelope surrounding the prokaryotic nucleoid.
  • The prokaryotic nucleoid contains DNA combined with histones. Histones are lacking in the eukaryotic nucleus.
  • The eukaryotic nucleus contains nucleoli. There are no nucleoli in the prokaryotic nucleoid.

Question 146 Which of the following cells will undergo osmotic lysis?

  • gram-negative cell in seawater
  • gram-positive cell in distilled water + penicillin
  • archean cell in distilled water + penicillin
  • gram-negative cell in distilled water

Question 147 Where are ribosomes found within eukaryotic cells?

  • bound to the outer surface of the rough endoplasmic reticulum
  • inside the mitochondria and chloroplasts
  • free in the cytoplasm
  • All of the choices are correct.

Question 148 Which of the following is found in the cytoplasm of eukaryotic cells, but is absent from the cytoplasm of prokaryotes?

  • water
  • DNA
  • endospores
  • a cytoskeleton

Question 149 Spirochetes and spirilla are both spiral-shaped bacteria. However, they differ in that spirochetes have a/an ________ and spirilla do not.

  • peritrichous flagella
  • N-acetylglucosamine
  • endoflagella (axial filament)
  • fimbriae

Question 150 Penicillin specifically interferes with peptidoglycan synthesis. Which of the following cells is most likely to be damaged by penicillin?

  • human cells
  • gram-positive bacterial cells
  • cells of archaea
  • yeast cells

Question 151 The plane in which a bacterial cell divides determines the arrangement of cells.

  • True
  • False

Question 152 The cell walls of bacteria and eukaryotes are very similar.

  • True
  • False

Question 153 The following bacterial structures increase the likelihood that bacteria will be associated with disease: capsules, fimbriae, and LPS.

  • True
  • False

Question 154 Bacteria do not have chloroplasts and therefore cannot perform photosynthesis.

  • True
  • False

Question 155 The cell membrane is a fluid structure that allows membrane proteins to move freely.

  • True
  • False

Question 156 Endospores can remain dormant for thousands of years. Once this dormant structure is provided appropriate nutrients and growth conditions, it will germinate to form a viable bacterial cell.

  • True
  • False

Question 157 Acid-fast bacteria demonstrate unique staining properties because of a special protein layer found in their cell walls.

  • True
  • False

Question 158 Penicillin is more effective against gram-negative bacteria than gram-positive bacteria because it specifically interferes with the synthesis of lipopolysaccharide.

  • True
  • False

Question 159 Epulopiscium fishelsoni is 0. 5 mm in diameter. It contains no nucleus and has peptidoglycan. Due to the size of this cell, it should be classified as a eukaryote.

  • True
  • False

Question 160 The endosymbiotic theory states that eukaryotic organelles evolved from symbiotic prokaryotes living within other prokaryotes.

  • True
  • False

Question 161 Bacteria growing in and on the human body, including normal microbiota as well as pathogens, are classified as ________.

  • thermophilic and halophilic
  • mesophilic and halophilic
  • mesophilic and heterotrophic
  • thermophilic and acidophilic
  • mesophilic and acidophilic

Question 162 An organism that you are studying grows at 4°C and at 25°C. However, it grows best at 20°C. This organism would be classified as a ________.

  • thermophile
  • mesophile
  • psychrophile
  • psychrotroph
  • halophile

Question 163 Through metabolism, pathogens often produce acids that interfere with their own growth. ________ are/is added to media to control pH changes.

  • Salts
  • Oxygen
  • pH indicators
  • Growth inhibitors
  • Buffers

Question 164 Which of the following terms are mismatched?

  • extreme thermophiles; 100°C
  • hyperthermophiles; no water
  • psychrophiles; 0°C
  • acidophiles; low pH
  • extreme halophiles; 30% salt

Question 165 Bacteria require nitrogen for the synthesis of ________.

  • lipids
  • proteins
  • sugars
  • carbohydrates
  • fatty acids

Question 166 What do all of these bacteria have in common? Bacteria in the rumen of cattle and sheep Bacteria in a sewage treatment plant Bacteria growing in the middle ear in chronic otitis media Bacteria growing on the teeth in dental plaque ____________________.

  • The bacteria are all fermenters.
  • The bacteria are all thermophilic.
  • The bacteria are most likely growing in biofilms.
  • The bacteria are all gram-positive.
  • The bacteria are all obligate aerobes.

Question 167 Which of the following is not a chemical requirement of all bacteria?

  • nitrogen
  • sulfur
  • carbon
  • molecular oxygen
  • mineral elements

Question 168 An organism that grows both in the presence and the absence of oxygen and uses oxygen when it is available is called a/an ________.

  • aerobe
  • anaerobe
  • aerotolerant anaerobe
  • microaerophile
  • facultative anaerobe

Question 169 A culture medium consisting of agar, peptone, and beef heart extract is a/an ________.

  • chemically defined medium
  • complex medium
  • selective medium
  • differential medium
  • enrichment medium

Question 170 Members of the genus Clostridium display the following properties: Gram-positive bacilli Endospore formation Anaerobic growth Which of the following would be appropriate for the culture of members of this genus?

  • blood agar plate in a candle jar
  • blood agar plate in an anaerobe jar
  • nutrient broth
  • sodium thioglycolate broth
  • both a blood agar plate in an anaerobe jar and sodium thioglycolate broth

Question 171 Martin Lewis agar is an enriched media (containing heated blood) designed for the growth of Neisseria gonorrhea. Antibiotics are added to suppress the growth of normal microbiota that may be found in patient specimens, yet permit the growth of Neisseria gonorrhea. This medium would best be described as ________.

  • selective media
  • reduced media
  • nutrient agar
  • differential media
  • defined media

Question 172 Niacin, when added to a medium, would be considered a/an ________.

  • carbon source
  • enzyme cofactor
  • electron carrier
  • reducing agent
  • organic growth factor

Question 173 Which of the following is not a step in binary fission?

  • cross-wall formation
  • cell elongation
  • invagination of the plasma membrane
  • replication of chromosomal DNA
  • lysis of the existing cell wall

Question 174 If a single bacterium replicated every 30 minutes, how many bacteria would be present in 2 hours?

  • 32
  • 16
  • 8
  • 4
  • 1

Question 175 In which phase of the growth curve is the population doubling time fastest?

  • lag phase.
  • death phase
  • log phase
  • stationary phase
  • logarithmic decline phase

Question 176 During the lag phase, ________.

  • nutrients are depleted
  • cells are decreasing in number
  • changes in pH occur
  • cells are growing in number
  • cells are engaged in intense enzymatic activity

Question 177 What phase of the cell cycle is extended in a chemostat?

  • death phase
  • stationary phase
  • logarithmic decline phase
  • log phase
  • lag phase

Question 178 All of the following are true of the plate count method except ________.

  • involves cell plating and growth
  • most commonly used method for assay of bacterial cell number
  • fast-completed in minutes
  • measures number of viable cells
  • dependable

Question 179 An unknown culture is assayed via the plate count method. After dilution of cells and incubation, no colonies are observed. Which of the following is not a possible explanation?

  • The wrong dilution was plated.
  • The incubation conditions were incorrect.
  • The bacterial cells formed invisible colonies.
  • The media did not support the growth of the microbes.
  • There were no cells in the culture.

Question 180 Blood agar used to observe hemolysis or clearing around Streptococcus pyogenes colonies is an example of a/an ________.

  • reducing media
  • selective media
  • differential media
  • enrichment media
  • isolation media

Question 181 Which of the following is true regarding infections in which biofilms are involved?

  • Bacteria in biofilms are more likely to be resistant to antibiotics.
  • Bacteria in biofilms are more likely to be motile.
  • Bacteria grow faster when part of a biofilm.
  • Bacteria in biofilms are more likely to produce endotoxin.

Question 182 Which of the following techniques will allow you to get isolated colonies on agar plates?

  • using enriched media
  • using a streak plate technique to inoculate the agar
  • filtrating the culture
  • using antibiotics in the agar

Question 183 Martian soil is inoculated into a glucose-containing medium. The radioactive form of carbon, 14C, is used in the glucose. After incubation for five days, which of the following would provide evidence suggesting that there is life on Mars?

  • no radioactivity
  • radioactive glucose
  • radioactive carbon dioxide
  • radioactive soil

Question 184 A medium containing lauryl sulfate inhibits growth of gram-positive bacteria. This medium is ________.

  • reduced
  • selective
  • enriched
  • differential

Question 185 S-S agar inhibits gram-positive bacteria. On this medium, bacteria that ferment lactose produce red colonies, and bacteria that do not ferment lactose produce colorless colonies. This medium is ________.

  • selective
  • differential
  • enriched
  • both selective and differential

Question 186 You inoculate two tubes of liquid culture media with 100 bacterial cells and incubate one tube at 37°C and the other at 55°C. After 48 hours, there are 20,000 bacteria/ml in the 37°C tube and 1,568,000 bacteria/ml in the 55°C tube. You conclude that this species is a ________.

  • hyperthermophile
  • mesophile
  • thermophile
  • psychrophile

Question 187 Quorum sensing refers to ________.

  • the ability of bacteria in a biofilm to grow on selective media
  • the ability of bacteria in a biofilm to use inorganic nitrogen sources
  • the ability of bacteria in a biofilm to communicate with each other and coordinate their activities
  • the ability of bacteria in a biofilm to sense O2

Question 188 All of the following can be used to preserve bacteria cultures except ________.

  • refrigeration
  • freezing quickly and storing at -70°C
  • lyophilization (freeze-drying)
  • storing cultures at room temperature (25°C)

Question 189 To look for bacteria that degrade petroleum, a culture medium containing crude oil, sodium nitrate, phosphate buffer, and magnesium sulfate is inoculated with soil. This medium is ________.

  • differential
  • chemically defined
  • complex
  • aerobic

Question 190 You are testing the effectiveness of food preservatives in cottage cheese. You need to determine the number of bacteria that can grow in the cottage cheese with and without preservatives. Which of the following test methods would be best to use?

  • turbidity
  • plate count
  • direct microscopic count
  • filtration

Question 191 If you grow E. coli in a glucose-minimal salts medium containing radioactively labeled nitrogen (15NO3-), the nitrogen will most likely be found in E. coli’s ________.

  • carbohydrates
  • waste products
  • enzymes
  • plasma membrane
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