exam 2 Flashcards
1
Q
Viruses have all the following except A. definite shape. B. metabolism. C. genes. D. ability to infect host cells. E. ultramicroscopic size.
A
B. metabolism.
2
Q
Host cells of viruses include A. human and other animals. B. plants and fungi. C. bacteria. D. protozoa and algae. E. All of the choices are correct.
A
E. All of the choices are correct.
3
Q
The core of every virus particle always contains A. DNA. B. capsomers. C. enzymes. D. DNA and RNA. E. either DNA or RNA.
A
E. either DNA or RNA
4
Q
Classification of viruses into families involves determining all the following characteristics except A. type of nucleic acid. B. type of capsid. C. presence of an envelope. D. biochemical reactions. E. nucleic acid strand number.
A
D. biochemical reactions.
5
Q
Which of the following represents a virus family name? A. Herpes simplex virus B. Herpesviridae C. Picornavirus D. Enterovirus E. Hepatitis B virus
A
B. Herpesviridae
6
Q
Virus capsids are made from subunits called A. envelopes. B. spikes. C. capsomeres. D. prophages. E. peplomers.
A
capsomeres
7
Q
Helical and icosahedral are terms used to describe the shapes of a virus A. spike. B. capsomere. C. envelope. D. capsid. E. core.
A
capsid
8
Q
Which of the following is correct about viruses?
A. cannot be seen with a light microscope
B. are procaryotic
C. contain 70S ribosomes
D. undergo binary fission
E. can be grown on nutrient agar
A
A. cannot be seen with a light microscope
9
Q
All of the following pertain to virus envelopes except they
A. are gained as a virus leaves the host cell membrane.
B. are gained as a virus leaves the nuclear membrane.
C. contain special virus proteins.
D. help the virus particle attach to host cells.
E. are located between the capsid and nucleic acid.
A
E. are located between the capsid and nucleic acid.
10
Q
T-even phages A. include the poxviruses. B. infect Escherichia coli cells. C. enter host cells by engulfment. D. have helical capsids. E. All of the choices are correct.
A
B. infect Escherichia coli cells.
11
Q
Which of the following is not associated with every virus? A. envelope B. capsomers C. capsid D. nucleic acid E. genome
A
envelope
12
Q
These structures are used by bacteriophages to attach to host cell receptors. A. sheath B. tail fibers C. nucleic acid D. capsid head E. None of the choices are correct.
A
B. tail fibers
13
Q
Which is incorrect about prophages?
A. present when the virus is in lysogeny
B. formed when viral DNA enters the bacterial chromosome
C. replicated with host DNA and passed on to progeny
D. cause lysis of host cells
E. occur when temperate phages enter host cells
A
D. cause lysis of host cells
14
Q
The correct sequence of events in viral multiplication is
A. penetration, replication, maturation, adsorption, assembly, release.
B. replication, penetration, maturation, assembly, absorption, release.
C. adsorption, penetration, replication, maturation, assembly, release.
D. assembly, maturation, replication, release, penetration, adsorption.
E. adsorption, release, maturation, replication, assembly, penetration.
A
C. adsorption [attachment] , penetration, replication, maturation, assembly, release.
15
Q
The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is
A. adsorption to the host cells.
B. injection of the viral nucleic acid into the host cell.
C. host cell synthesis of viral enzymes and capsid proteins.
D. assembly of nucleocapsids.
E. replication of viral nucleic acid.
A
B. injection of the viral nucleic acid into the host cell.
16
Q
Viruses acquire envelopes around their nucleocapsids during A. replication. B. assembly. C. adsorption. D. release. E. penetration.
A
D. release
17
Q
Which of the following will not support viral cultivation? A. live lab animals B. embryonated bird eggs C. primary cell cultures D. continuous cell cultures E. blood agar
A
E. blood agar
18
Q
In general, most DNA viruses multiply in the host cell's \_\_\_\_\_, while most RNA viruses multiply in the host cell's \_\_\_\_\_. A. nucleus, cytoplasm B. cytoplasm, cell membrane C. cell membrane, cytoplasm D. cytoplasm, nucleus E. nucleus, endoplasmic reticulum
A
A. nucleus, cytoplasm
19
Q
Host range is limited by A. type of nucleic acid in the virus. B. age of the host cell. C. type of host cell receptors on cell membrane. D. size of the host cell. E. All of the choices are correct.
A
C. type of host cell receptors on cell membrane.
20
Q
The virus-induced, specific damage to the host cell that can be seen in a light microscope is called A. lysogeny. B. budding. C. plaques. D. cytopathic effects. E. pocks.
A
D. cytopathic effects.
21
Q
Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called A. lysogeny. B. budding. C. plaques. D. cytopathic effects. E. pocks.
A
C. plaques.
22
Q
Viral growth in bird embryos can cause discrete, opaque spots in the embryonic membranes called A. lysogeny. B. budding. C. plaques. D. cytopathic effects. E. pocks.
A
E. pocks.
23
Q
Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called A. latent B. oncogenic. C. prions. D. viroids. E. delta agents.
A
latent
24
Q
Which of the following is a type of cytopathic effect? A. inclusions in the nucleus B. multinucleated giant cells C. inclusions in the cytoplasm D. cells round up E. All of the choices are correct.
A
E. All of the choices are correct
25
Uncoating of viral nucleic acid
A. does not occur in bacteriophage multiplication.
B. involves enzymatic destruction of the capsid.
C. occurs during penetration in the multiplication cycle.
D. occurs before replication.
E. All of the choices are correct.
E. All of the choices are correct.
26
```
Infectious protein particles are called
A. viroids.
B. phages.
C. prions.
D. oncogenic viruses.
E. spikes.
```
prions
27
```
Infectious naked strands of RNA are called
A. viroids.
B. phages.
C. prions.
D. oncogenic viruses.
E. spikes.
```
viroids
28
```
Creutzfeld-Jacob disease is
A. caused by a chronic latent virus.
B. initiated by an oncogenic virus.
C. caused by a viroid.
D. a spongiform encephalopathy of humans.
E. also called "mad cow disease".
```
D. a spongiform encephalopathy of humans.
29
Satellite viruses are
A. also called viroids.
B. dependent on other viruses for replication.
C. the cause of spongiform encephalopathies.
D. significant pathogens of plants.
E. All of the choices are correct.
B. dependent on other viruses for replication.
30
All of the following is correct about treating viral diseases except
A. viruses are killed by the same antibiotics that kill bacteria.
B. many antiviral drugs block viral replication.
C. many antiviral drugs cause severe side effects.
D. interferons show potential for treating and preventing viral infections.
E. All of the choices are correct.
A. viruses are killed by the same antibiotics that kill bacteria.
31
```
The capsomers are made of
A. DNA.
B. RNA.
C. lipids.
D. protein.
E. carbohydrate.
```
carbohydrate/ idk proteins
32
```
Viruses that consist of only a nucleocapsid are considered
A. simple viruses.
B. complex viruses.
C. naked viruses.
D. viroids.
E. incomplete viruses.
```
C. naked viruses.
33
The nucleocapsid consists of
A. the capsomers assembled into the capsid.
B. the nucleic acid of the virus only.
C. the nucleic acid along with the capsid.
D. the envelope and capsid.
E. the envelope, nucleic acid, and capsid.
C. the nucleic acid along with the capsid.
34
Which of the following parts of a virus is not always present?
A. envelope
B. nucleic
acid
C. capsid
D. capsomers
E. None of the choices are optional parts of a virus.
envelope
35
```
Which of the following viruses did D. Ivanovski and M. Beijerinck work with?
A. rabies
B. smallpox
C. tobacco mosaic virus
D. herpes
E. Epstein-Barr virus
```
C. tobacco mosaic virus
36
When a virus enters a lysogenic phase, it means
A. the virus is integrated into the DNA of the host cell and is latent.
B. the virus is bursting through the host cell membrane.
C. the virus is starting biosynthesis of its nucleic acid.
D. the virus will remain in circulation and not continue infecting its host.
E. the number of viruses in the host is decreasing as the immune system becomes effective.
A. the virus is integrated into the DNA of the host cell and is latent.
37
```
How do enveloped animal viruses exit their host?
A. Budding or exocytosis
B. Bursting the host cell
C. Rupturing the virus
D. Endocytosis
E. None of these are correct
```
A. Budding or exocytosis
38
Viruses are ultramicroscopic because they range in size from 2 mm to 450 mm.
FALSE-- nanometers
39
Spikes are glycoproteins of the virus capsid.
FALSE
40
Which of the following refers to the term metabolism?
A. all the reactions in a cell or organism
B. all the reactions in a cell that break down molecules only
C. all the reactions in a cell that build new molecules only
D. all the reactions in a cell that decompose molecules only
A. all the reactions in a cell or organism
41
```
Which of the following best describes an endergonic reaction?
A. absorbs energy from the environment
B. is coupled with another reaction
C. is involved in biosynthesis
D. releases energy into the environment
```
A. absorbs energy from the environment
42
Chemotrophs obtain their energy from which of the following?
A. inorganic chemical reactions only
B. light energy
C. organic chemical reactions only
D. organic and inorganic chemical reactions
D. organic and inorganic chemical reactions
43
```
Which of the following describes a molecule that had an electron removed/ lost?
A. anabolized
B. electronated
C. oxidized
D. reduced
```
C. oxidized
44
```
7. Which of the following are inorganic molecules, are elements (Mg, Fe, Ca) that bind to enzymes?
A. apoenzymes
B. coenzymes
C. cofactors
D. holoenzymes
```
C. cofactors
45
8. Which of the following best describes catabolic pathways?
A. They always absorb energy.
B. They break down large molecules into smaller components.
C. They build up large molecules from smaller components.
D. They must be coupled with the breakdown of ATP.
B. They break down large molecules into smaller components.
46
```
9. Which group comprises all lithotrophs?
A. algae
B. autotrophs
C. microbes
D. plants
```
C. microbes
47
```
10. Which is a common electron acceptor in catabolic reactions?
A. ATP
B. FADH2
C. NAD+
D. NADPH
```
C. NAD+
48
```
11. The reaction that breaks down ATP to form ADP and inorganic phosphate is classified as which of the following?
A. endergonic
B. exergonic
C. nonspontaneous
D. reduction
```
B. exergonic
49
```
12. Which of the following is an inhibitor that binds to the active site of an enzyme?
A. a competitive inhibitor
B. a noncompetitive inhibitor
C. an allosteric inhibitor
D. an uncompetitive inhibitor
```
A. a competitive inhibitor
50
```
13. Glycolysis produces a net gain of which of the following?
A. two ATP, two NADH, and two pyruvates
B. two ATP, two NADH, and four pyruvates
C. two ATP, four NADH, and two pyruvates
D. four ATP, two NADH, and two pyruvates
```
A. two ATP, two NADH, and two pyruvates*
51
15. Which of the following best describes a transition reaction?
A. a reaction that converts pyruvate to acetyl CoA with the release of carbon dioxide
B. a series of reactions that convert citric acid to oxaloacetate
C. an optional reaction that transports pyruvate into the mitochondrion
D. the reaction that converts glucose to glucose-6-phosphate in glycolysis
A. a reaction that converts pyruvate to acetyl CoA with the release of carbon dioxide
52
```
16. Which of the following is not a product of the Krebs cycle?
A. carbon dioxide
B. GTP, which is converted to ATP
C. NADH
D. pyruvate
```
D. pyruvate
53
```
20. Which of the following are enzymes that break down proteins?
A. amylases
B. oxidases
C. oxygenases
D. proteases
```
D. proteases
54
```
21. Fatty acids are often degraded using which set of reactions?
A. β-oxidation
B. glycolysis
C. photophosphorylation
D. the tricarboxylic acid cycle
```
A. β-oxidation*
55
```
22. Triglycerides are broken down by which of the following?
A. lipases
B. nitrogenases
C. phospholipases
D. proteases
```
A. lipases
56
```
23. During the Krebs cycle, FAD is reduced to which of the following?
A. FADH
B. FADH2
C. NADH
D. NADH2
```
B. FADH2
57
which of the following is the purpose of fermentation?
A. to produce carbon dioxide
B. to produce large quantities of additional energy
C. to regenerate NAD+
D. to regenerate oxygen
C. to regenerate NAD+*
58
25. ATP is produced through oxidative phosphorylation when which of the following occurs?
A. FADH2 donates electrons to succinate dehydrogenase
B. H+ moves through ATP synthase
C. NADH donates electrons to NADH dehydrogenase
D. the light-independent reactions fix CO2
B. H+ moves through ATP synthase
59
28. Which of the following occurs when molecules are broken down using β-oxidation?
A. Carbon dioxide is removed.
B. Three carbon propyl groups are removed.
C. Two carbon acetyl groups are removed.
D. Two carbon acyl groups are removed
C. Two carbon acetyl groups are removed.
60
Which of the following best defines chemiosmosis?
A. the disruption of the inner mitochondrial membrane, which dissipates energy
B. the movement of electrons from one acceptor to another
C. the movement of hydrogen ions through ATP synthase
D. the series of reactions that regenerate oxaloacetate
C. the movement of hydrogen ions through ATP synthase
61
```
30. Which of the following is the most acidic location in a mitochondrion?
A. the intermembrane space
B. the matrix
C. within the outer membrane
D. within the thylakoid
```
A. the intermembrane space
62
Glycolysis cannot occur in an anaerobic environment.
false
63
35. Nitrogen is fixed to ammonia by cyanobacteria and other microbes.
t
64
37. Fermentation is necessary because it provides additional energy compared with glycolysis alone.
f
65
39. Oxygen is necessary for an electron transport chain to function.
f
66
```
Bacteria most commonly reproduce using which of the following methods?
A. binary fission
B. budding
C. meiosis
D. mitosis
```
A. binary fission
67
```
1. Which structure separates new daughter cells in binary fission?
A. the crescent
B. the division septum
C. the FtsZ
D. the spindle apparatus
```
B. the division septum
68
```
2. Which of the following is another term for generation time?
A. doubling time
B. growth rate
C. mitotic index
D. replication index
```
A. doubling time
69
```
3. Which of the following best describes culture density?
A. another term for a batch culture
B. the number of cells per unit volume
C. the reproducible pattern of growth
D. the total number of cells
```
B. the number of cells per unit volume
70
4. Which of the following is the correct order of phases of growth in the growth curve of a batch culture?
lag/ log/ stationary/ death
71
```
Which of the following is not a common way bacteria divide?
A. binary fission
B. budding
C. fragmentation
D. sporulation
```
sporulation
72
```
5. Which of the following is the term for free-living bacteria?
A. biofilms
B. pathogenic
C. planktonic
D. sessile
```
C. planktonic
73
```
6. Which of the following is not a reactive oxygen species?
A. atmospheric oxygen
B. peroxides
C. singlet oxygen
D. superoxide
```
A. atmospheric oxygen
74
7. Which of the following best describes FtsZ?
A. a cytoskeletal protein in eukaryotic cells
B. the protein that assembles the Z ring, which forms a divisome before division by binary fission
C. the protein that forms within the central structure of the new cell wall and septum that separates the daughter cells during binary fission
D. the protein that gives structure to spirochetes, contributing to their unusual shape and motility
B. the protein that assembles the Z ring, which forms a divisome before division by binary fission
75
```
Which microbial pathogen has an unusually long doubling time?
A. Bacillus subtilis
B. Escherichia coli
C. Mycobacterium leprae
D. Salmonella typhimurium
```
C. Mycobacterium leprae
76
```
The initial cells added to a batch culture are called which of the following?
A. the batch
B. the culture
C. the inoculum
D. the lagging cells
```
C. the inoculum
77
```
10. Which best describes bacterial growth during the log phase of the growth curve?
A. exponential
B. linear
C. S-shaped
D. stationary
```
A. exponential
78
```
12. Which type of system is used to maintain bacteria in a relatively constant environment, allowing them to stay in the log phase of growth?
A. bacteriostat
B. chemostat
C. maintenance state
D. stable state
```
B. chemostat
79
11. Which best defines the term “persisters?”
A. cells that form endospores rapidly when environmental conditions become unfavorable, allowing them to survive in a dormant state without causing disease symptoms
B. cells that persist in the log phase for much longer than other cells
C. cells that rapidly colonize new environments by releasing virulence factors and moving through tissues, allowing them to contribute to severe systemic infections.
D. cells with relatively slow metabolic rates that survive longer than others during the death phase and that can cause chronic infections
D. cells with relatively slow metabolic rates that survive longer than others during the death phase and that can cause chronic infections
80
```
13. Which of the following is an indirect method of measuring numbers of bacterial cells?
A. a Coulter counter
B. a Petroff-Hausser chamber
C. microscopic cell count
D. turbidity measurements
```
D. turbidity measurements
81
14. Which of the following is not a common step in preparing a pour plate to make a count of microbial numbers?
A. A serial dilution is performed.
B. Bacteria are spread across the agar, using a sterile spreader.
C. Bacteria are mixed with warm agar and poured onto a Petri plate, then swirled.
D. The sample is allowed to grow, then colonies are counted
B. Bacteria are spread across the agar, using a sterile spreader.*
82
15. Which of the following best describes why extracellular polymeric substances are important?
A. They are chemicals produced as part of the immune response to microbial invasion.
B. They are components of a biofilm secreted by the host cells as an immune response to wall off the pathogens.
C. They are components of a biofilm secreted by the microbes present.
D. They are secreted by free-living bacteria as virulence factors to allow them to penetrate the bloodstream.
C. They are components of a biofilm secreted by the microbes present.
83
```
16. Which of the following media is commonly used to determine the oxygen requirements of a bacterial species?
A. chocolate agar medium
B. Mueller-Hinton agar medium
C. thioglycolate medium
D. tryptic soy medium
```
C. thioglycolate medium
84
17. Which of the following best describes how a microaerophile would grow in a thioglycolate tube culture?
A. a short distance below the top of the medium, but not at the top
B. at the bottom of the medium only, with no growth in the middle or top
C. near and at the top of the medium, with no growth at the bottom
D. throughout the medium
A. a short distance below the top of the medium, but not at the top
85
```
18. Which of the following is not an example of an enzyme used to detoxify reactive oxygen species?
A. catalase
B. permeases
C. peroxidases
D. superoxide dismutases
```
B. permeases
86
```
20. Which of the following is the most common category of bacteria?
A. acidophiles
B. alkaliphiles
C. extreme alkaliphiles
D. neutrophiles
```
D. neutrophiles
87
```
21. Human pathogens are generally which type of microbe?
A. mesophiles
B. psychrophiles
C. psychrotrophs
D. thermophiles
```
A. mesophiles
88
```
22. Food spoilage is often caused by which type of microbe?
A. mesophiles
B. psychrophiles
C. psychrotrophs
D. thermophiles
```
C. psychrotrophs
89
```
26. In batch culture, how does the log phase of the bacterial growth curve appear?
A. exponential on a semi-log scale
B. linear on a semi-log scale
C. logarithmic on an arithmetic scale
D. logarithmic on a semi-log scale
```
B. linear on a semi-log scale
90
```
23. Which type of microbes thrive in the Great Salt Lake?
A. barophilic
B. barotolerant
C. extreme halophiles
D. halotolerant
```
C. extreme halophiles
91
```
25. Which range of the electromagnetic spectrum is considered photosynthetically active radiation?
A. from ultraviolet to near infrared
B. from visible light to near infrared
C. in near infrared only
D. in visible light only
```
B. from visible light to near infrared
92
27. Which of the following best describes the enzymes of extreme alkaliphiles?
A. They have many acidic amino acids.
B. They have relatively high isoelectric points.
C. They have relatively high numbers of negatively charged surface amino acids.
D. They have the ability to pump protons out of cells.
B. They have relatively high isoelectric points.
93
29. Which of the following best describes the cell membranes of microbes that thrive at low temperatures?
A. They have only one layer.
B. They have relatively even amounts of saturated and unsaturated fatty acids.
C. They have relatively high amounts of saturated fatty acids.
D. They have relatively high amounts of unsaturated fatty acids
D. They have relatively high amounts of unsaturated fatty acids
94
30. If you grow two species of bacteria on mannitol salt agar to determine which can ferment mannitol, and you know both species can grow on the medium, which type of medium is the agar?
A. differential
B. selective
C. both a differential medium and a selective medium
D. neither a differential medium nor a selective medium
A. differential*
95
```
31. Which of the following pigments are especially useful at great depths, where less light penetrates?
A. bacteriorhodopsin and carotenoids
B. carotenoids and chlorophylls
C. fucoxanthin and carotenoids
D. fucoxanthin and phycobilins
```
D. fucoxanthin and phycobilins
96
```
32. Which of the following microbes uses light energy to pump hydrogen and sodium?
A. Bacteriodetes
B. Campylobacter
C. Chlamydomonas
D. Halobacterium
```
D. Halobacterium
97
33. Which of the following is true of using a Petroff-Hausser chamber to do a direct cell count?
A. Identical squares, all the same size, are etched into the slide.
B. If the sample was diluted, then the concentration must be corrected accordingly.
C. It is not necessary to know the volume of the sample added to the slide.
D. The chamber does not resemble a hemocytometer.
B. If the sample was diluted, then the concentration must be corrected accordingly.
98
34. Which of the following would be the best choice for distinguishing living and dead bacteria in a cell count?
A. using a Coulter counter or other electronic counting method
B. using a streak plate, spread plate, or pour plate
C. using gram staining or a similar method
D. primary and secondary fluorescent stains
D. primary and secondary fluorescent stains
99
```
35. What is the goal number of CFUs on a spread plate if a serial dilution is done correctly?
A. 1–10 per plate
B. 30–300 per plate
C. 400–900 per plate
D. 1000 or more per plate
```
B. 30–300 per plate
100
36. The largest component of the dry weight of a biofilm is usually extracellular polymeric substances.
true
101
37. Generation time in prokaryotes refers to the amount of time required for the doubling of the population through a single round of binary fission.
true
102
38. Estimates of coliforms in water are often made using most probable number techniques
true
103
40. Halotolerant microbes cannot grow without high concentrations of salt.
False
104
Fungi can generally thrive in drier environments than can bacteria.
true
105
MacConkey agar can be used to select for the growth of gram-positive bacteria, making it especially useful to study Enterobacteriaceae.
false
106
On of the principal capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a(n)_________ capsid
```
A. helical
B. icosahedral
C. spiked
D. complex
E. buckeyball
```
B. icosahedral
107
When a bacterium acquires a trait from its temperate phage, it is called
```
A. lysongenic conversion
B. transcription
C. viral persistence
D. translation
E. Transformation
```
A. lysongenic conversion
108
Which of the following is not a typical capsid shape?
```
A. Icosahedron
B. Tetrahedral
C. Complex
D. Helical
E. All of the choices are correct
```
B. Tetrahedral
109
The activation of a prophage is called:
```
A. adsorption
B. transformation
C. induction
D. lysogeny
E. activation
```
C. induction
110
Reverse transcriptase synthesizes
A. DNA from RNA
B. RNA from DNA
C. a negative RNA strand from a positive RNA strand
D. the positive RNA strand from a negative RNA strand
E. None of the choices is correct
A. DNA from RNA
111
Lysogeny refers to
```
A. viral genome inserting into bacterial host chromosome
B. latent state of herpes infections
C. virion exiting host cell
D. none of the choices is correct
E. altering the host range of a virus
```
A. viral genome inserting into bacterial host chromosome
112
Which of the following best explains how a bacterial prophage can negatively impact human health?
A. the lysis of infected human cells results in the release of numerous phage particles
B. the entry of the prophage shuts down DNA replication in human cells
C. the entry of the prophage causes cessation of protein synthesis in human cells
D. toxins or enzymes are produced by the infected bacterial pathogen that cause pathology in humans
D. toxins or enzymes are produced by the infected bacterial pathogen that cause pathology in humans
