1
Q
Why is the glyoxylate cycle necessary for growth on acetate but not on succinate?
a. To utilize simple carbon compounds as a carbon source when complex sources (glucose) are not available
b. To produce pyruvate
c. For the formation of ATP from respiratory electon flow
d. No correct answer
e. To utilize complex carbon compounds as a carbon source when simple sources are not
available
A
a. To utilize simple carbon compounds as a carbon source when complex sources (glucose) are not available
2
Q
Peptidoglycan
A
bacterial cell wall
3
Q
Branched hydrocarbons linked to glycerol
A
archael cell membrane
3
Q
Phospholipid
A
bacterial cell membrane
4
Q
Varied composition but lacking peptidoglycan
A
archaeal cell wall
5
Q
A glass capillary tube containing a chemical was placed inside a turbid pure culture of cells. Most cells accumulated inside a capillary forming a swarm around the open tip. The chemical is likely
A
e. An attractant to all cells and some by chance were not in the tube
6
Q
Two bacterial species have a single polar flagellum. Bacterial species #1 is capable of moving toward light but not glucose. Bacterial species #2 responds to glucose but not light. Microbiologists would define species #1’s movement as _______
A
phototaxis
7
Q
These organisms are present in compost piles and hot springs
A
thermophiles
7
Q
Their range of pH may be 2.0 up to 6
A
acidophile
8
Q
This group requires oxygen for metabolism, just like us
A
obligate aerobe
8
Q
Organisms that are inhibited or killed when oxygen is present
A
obligate anaerobes
9
Q
This group has most of the pathogens as they grow at human body temperature
A
mesophile
10
Q
They do not or cannot use oxygen
A
anaerobe
11
Q
They require relatively high levels of salt
A
halophile
12
Q
An unknown replication enzyme is added to the following substrate and generates the following product. What is the enzyme called?
A
DNA helices
12
Q
Mycoplasma
A
Lack of cell wall
13
Q
Archaeal membranes are distinguished from bacterial and eukaryotic membranes by the presence of …
A
Ether-linked lipids
13
Q
A bacterium with multiple flagella at one pole would be defined by a microbiologist as being …
A
Lophotrichous
13
Q
Which enzyme is NOT present in a replisome
A
a. RNA polymerase
14
Q
Lysozyme acts on bacteria by
A
d. Disrupting the cell wall of gram-positive bacteria
15
Q
Consider some of the ongoing cellular activities within the microbial community. Which of the following is NOT a property/process of all living cells?
A
differentiation
16
Q
What is the advantage of phase-contrast microscopy over bright-field microscopy. a. Resulting image-dark cells on a light background
b. Live cells can be visualized
c. Improves image contrast of unstained cells
d. Phase ring amplifies difference in the refractive index of cell and surrounding
A
e. All answers are correct
16
Q
Cells of Escherichia coli transport glucose via phosphotransferase system. What is the source of energy that drives the transport event?
A
Phosphoenolpyruvate
17
Q
Teichoic acid that are prresent on the cell wall of Listeeria monocytogenes belong to what group of microorganisms
A
Gram + bacteria
18
Which of the following organic compounds is the most abundant in microorganisms
carbohydrates
19
Fermentation of compounds results in the production of many by-products, but the map( purpose is actually to oxidize NADH to NAD+ so that another round of grycofysis can occur and more ATP is generated.
True
20
The exact composition of 1... is known. 2.... inhibit the growth of some microbes. 3... are used to culture fastidious microbes, particularly pathogens
1. defined media
2. Selective media
3. Enriched media
21
Resoliving is how far apart two adjacent objects must be before a given lens shows a discrete entities
True
22
If a heterotrophic bacterium were grown in a minimal glucose medium and transferred during exponential growth phase into the complex LB medium (peptone, yeast extract, NaCl and agar), the cell would have a relatively
b. Short lag phase because of the availability of amino acids and other nutrients. +
23
During this phase of bacterial growth, cells are sensing the environment, synthesizing ribosome and beginning DNA replication, but no cell division can be detected with a spectrophotometer?
lag phase
24
Refer to the image below. Determine the concentration or dilution factor for the tubes and plates. From the original culture, 1mL of broth was transferred to tube A which contains 9mL of sterile water. Then 1 mL from tube A is transferred to tube B and then 1 mL from tube B is transferred to tube C.
a. 1 mL from tube B is placed on tube C. What is the dilution on Plate C? 0.01+
b. 1 mL from tube C is placed on plate D. What is the dilution on Plate D? 0.001
c. If 60 colonies grew on plate A, how many CFU were in the original? 6*10^4 CFU/ml
24
an organism with a growth T optimum of 15C or lower and a maximum growth temperature below 20C
Psychrophile
25
a species of Bacteria or Archaea whose growth T optimum is 80C or greater
Hyperthermophile
25
an organism whose growth T optimum lies between 45-80C
Thermophile
26
an organism that growth best at T between 20 and 40C
Mesophile
26
capable of growing at low T but having an optimum above 20C
Psychrotolerant
27
During chemotaxis, attractants increase the rate of autophosphorylation, whereas repellants decrease this rate
False
28
Why are the pour-plate and spread-plate techniques to enumerate cells OFTEN favored over traditional microscopy cell counting in today’s microbiology laboratories?
c. Only viable cells are counted
29
Which period of the bacterial growth curve begins as nutrients become limited and is defined as the number of dying cells equal to the number of dividing cells?
Stationary phase
30
Which of the following enzymes is present in obligate anaerobes to combat toxic forms of oxygen such as hydrogen peroxide and superoxide anions?
a. All of them
b. Catalase
c. None of them
d. Superoxide dismutase
e. peroxidase
none of them???
31
The filamentous DNA phages are unusual, because they
a. Lyse the host cell
b. Are released from the host without the host being lysed
c. Have linear genomes
d. Replicate without a host
b. Are released from the host without the host being lysed
31
The Baltimore Scheme to classify viruses contains total of 1... groups based on 2...
1. SEVEN
2. GENOME COMPOSITION AND TRANSCRIPTION MECHANISM
32
The term... is used to reference concentrations of viruses
TITER
32
Why is the T4 genome resistant to restriction enzymes?
a. It modifies its DNA by methylating nucleotides
b. It has an ssDNA genome
c. It modifies its DNA, using 5-hydroxymethylcytosine instead of cytosine
d. It has an RNA genome
c. It modifies its DNA, using 5-hydroxymethylcytosine instead of cytosine +
33
BCG vaccine is valuable to clinical medicine because it is prepared from the Mycobacterium bovis strain that was attenuated and therefore, it is ___________.
Virulence reduced
33
Quinolones like ciprofloxacin inhibit DNA gyrase and topoisomerase IV and thus
a. Cause a shortage of peptidoglycan precursors that weakens the cell wall, leading to lysis
b. Result in the ribosome misreading mRNAs
c. Interfere with unwinding of DNA during replication
d. Lead to pore formation and depolarization of the cell membrane
c. Interfere with unwinding of DNA during replication +
34
Reverse transcriptase is a
A)RNA-dependent DNA polymerase.
1) DNA-dependent DNA polymerase.
C) RNA-dependent RNA polymerase.
D) DNA-dependent RNA polymerase.
b. RNA-dependent DNA polymerase +
35
A mutation that results in the premature halting of transcription (and, consequently, protein translation) of a particular gene is a ______ mutation.
nonsense
36
Which is NOT true regarding plaque assays?
a. Viral titers are expressed as plaque-forming units (PFU)
b. Top agar containing a dilution of virions and bacteria is poured on an agar plate
c. Plaques are clear zones seen because viruses lysed the host cells area
d. Plaque assays are used to quantify lysogenic phages as well as lytic phages
d. Plaque assays are used to quantify lysogenic phages as well as lytic phages
37
Bacteriophage lambda is an example of having a prophage replication cycle, which replicates
a. Independently of its host while the lytic genes are expressed
b. Along with its host while the lytic genes are not expressed
c. Along with its host while the lytic genes are expressed
d. Independently of its host while the lytic genes are not expressed
Along with its host while the lytic genes are not expressed
38
Endotoxins are generally less toxic than exotoxins. What cell structure components may serve as an endotoxin structure in Gram negative Bacteria?
b. Lipoteichoic acid
c. Cytoplasmic membrane
d. Lipopolysaccharide
e. porin
Lipopolysaccharide
39
During penetration of an Escherichi coli cell by T4 bacteriophage
a. T4 lysozyme facilitates membrane fusion, allowing the phage to enter the cell
b. The envelope fuses with the cell membrane, allowing the phage nucleocapsid to enter the cell
c. T4 lysozyme makes pore in the cell wall, the tail sheath contracts, and the phage DNA
is injected into the cell
d. Integrase makes a pore in the cell wall, the tail sheath contracts, and the phage DNA is
injected into the cell.
T4 lysozyme makes pore in the cell wall, the tail sheath contracts, and the phage DNA is injected into the cell
40
During chemotaxis, attractants increase the rate of autophosphorylation, whereas repellants decrease this rate
False
40
The diphtheria toxin is the result of a:
a. lysogenic infection of a bacterium
b. cancer
c. productive infection of a bacterium
d. phage therapy
a. lysogenic infection of a bacterium ✔
41
The main criterion for differentiation between Staphylococcus spp. And Streptococcus spp. Is the catalase test, where Staphylococci are catalase positive, whereas Streptococci are catalase negative.
True
41
Which viral replication pathway is associated with latent infections?
a. endogenous retroviruses
b. Lytic
c. no correct answer
d. Most RNA viral replication
e. Lysogenic
Lysogenic
42
Explain why the presence of a capsule or slime layer would benefit a bacterial cell
a. These outer layers can aid in attachment to solid surfaces +
43
Some prokaryotes can move along a solid surface by gliding. Name one of the two distinct mechanisms listed below that mediate gliding
Pili
44
A pure culture consists of which of the followinga.
a. Similar gram-stain reactions
b. Turbidity
c. One genus of microbe
d. One species of microbe
e. One streak
One species of microbe
44
Enzyme that is able to break the glycosidic bond that links monomers of peptidoglycan present in the cell walls of bacteria:
Lysozyme
44
Cells of E.coli transport glucose via phosphotransferase system. What is the source of energy that drives the transport event?
Phosphoenolpyruvate
45
The energy released from redox reactions fuels energy-requiring cell functions. Why is acetyl phosphate considered an energy rich compound while glucose 6-phosphate is not?
Because when acetyl phosphate is hydrolysed it releases more than 30kJ/mol energy.
While glucose 6-phosphate releases less than it. G0 must be more than 3kJ/mol for the
molecule to be considered energy rich
45
A medium containing following compounds 15g of glucose, 5g of yeast extract, 5 g of peptone, 2g of KH2PO4, 1000 ml distilled water (pH 7), for culturing of either E,coli of L.mesenteroides will be classified as
Complex
46
Endotoxin produced by gram-negative bacteria is present in ...
Lipopolysaccharide
46
Thiomargarita namibiensis is an example of chemolithotrophs, which involve
Oxidation of inorganic compounds
47
The following are all characteristic of endospore except
a. Very low water content
b. A thick layer of peptidoglycan
c. Granules of PHB
d. Deposits of calcium and dipicolinic acid
e. A thick external layer of protein known as the spore coat
Granules of PHB
47
A facultative anaerobe is placed in an environment with atmospheric concentrations of oxygen. Which of the following would be a correct result?
Aerobic respiration will occur
48
Which component of the lipopolysaccharide is antigenically variable between strains of bacteria of the same species?
O-antigen
48
When glucose is formed from the element, free energy formation is -917.2 kJ/mol. Does it mean that energy is ...
released
49
In the pour-plate technique, 63 colonies were found on the plate where 1 ml of a 1:100,000 dilution was plated. How many colony-forming units per ml were there?
CFU/mL= Dilution plated/Number of colonies
CFU/mL=63×10^5
CFU/mL=6.3×10^6
50
From the list below, choose the structure that is unique to Gram-positive cells.
a. LPS
b. Peptidoglycan
c. Teichoic acid
d. Flagella
c. Teichoic acid
51
cyanobacteria are capable of producing their own food. They evolved the ability to move toward conditions that will help them synthesize the organic compounds and use them for metabolism. This type of movement for this type of bacteria most likely be a process called
phototaxis4
51
Many prokaryotes have one or more plasmids in addition to their chromosome
True
51
Explain why dipicolinic acid is only found in endospore and not in vegetative cells
a. It binds to calcium ions to stabilize DNA at room temperatures
in vegetative cells
b. It binds free water and aids in dehydration, which would be detrimental to vegetative
cells
c. It binds free water and aids in transporting that water into vegetative cells, which would
be detrimental endospores
d. In binds to calcium ions to destabilize DNA at room temperature
e. No correct answer
It binds free water and aids in dehydration, which would be detrimental to vegetative
cells
52
A mixed population of bacteria from a natural source, if spread out on the surface of a solid medium, would produce a series of localised growth, termed ...
colonies
53
Fermentation of compounds results in the production of many by-products, but the major purpose is actually to oxidize NADH to NAD+ so that another round of glycolysis can occur and more ATP is generated
True
53
Many bacteria move in physically distinct environments, such as soil, mucus, host cell surface, and planktonic environments, for survival in nature using the flagellum. Which of the following statements about flagella is false.
a) Bacterial flagella made of flagellin protein subunits
b) In flagellar motion, the basal body acts as a motor
c) Flagella can be anchored to a cell in different locations
d) Flagellar rotation allows for gliding motion
e) The main part of the flagellum is called the filament
Flagellar rotation allows for gliding motion
54
Flagella uses energy from ATP to generate energy for rotation
False
55
What happens if bacteria lose the ability to tumble? Without tumbling bacteria
a) Will not be able to change direction of movement
b) Will start gliding
c) Will start moving faster toward the chemoattractant
d) All of these will take place
Will not be able to change direction of movement
56
Achaeans have an extension of the surface which is called archaea. This structure
a) Rotates like bacterial flagella
b) Serves function similar to conjugation pilus
c) Serves function similar to fimbriae
d) Protects from UV light
e) Energy requirement for movement is met by dissipation of the proton motive force
Rotates like bacterial flagella
57
compared to eukaryotes, bacteria and archaea have ____ surface- to volume ratios, causing _____ nutrients exchange
higher/higher
58
Some bacterial cells are capable of gliding. Which of the following is not true about gliding?
a) Gliding bacteria are typically filamentous or rod-shaped in morphology
b) Gliding process requires that the cells be in contact with a solid surface
c) Archeal cella are best at gliding since they don't possess flagella
d) A polysaccharide slime is produced by cells and deposited onto solid surface
e) Repeated extension and retraction of type 4 pilli
Archeal cella are best at gliding since they don't possess flagella
58
The structure that allows archeal cells to swim required one of the following in order to function
a) Dissipation of the proton motive force
b) The hydrolysis of ATP
c) Extrusion of the polysaccharide slime
d) Dissipation of the proton motive force and extrusion of the polysaccharide slime
e) Using type 4 pilus
The hydrolysis of ATP
59
Of the many types of proteins found in the cytoplasmic membrane is involved in the chemotactic response and is called a
chemoreceptor
60
When given information about chemical composition of cells, you see that there’s a lipopolysaccharide (LPS) layer is found. What type of cell is it?
gram - bacteria
61
which of the following if true about the cell walls of certain methane-producting archea (methanogens)
a) b) Cell wall contains a peptidoglycan
The glycosidic bonds between the sugar derivatives of archeal cell wall polysaccharide
are 𝛽-1,4
c) d) Cell wall polysaccaride is easily destroyed by lysozyme
Cell wall polysaccharide is easily destroyed by penicillin
e) Disaccharide monomer differs from bacterial: composed on N-acetyglucosamine (inpeptidoglycan) and N-acetylalosaminuronic acid
Disaccharide monomer differs from bacterial: composed on N-acetyglucosamine (in
peptidoglycan) and N-acetylalosaminuronic acid
62
Which of the following is not true about lipopolysaccaride (LPS) layer?
a) Belong to pathogen-associated molecular pattern molecules (PAMP’s) that are
reconised by immune system of animals
b) An important biological activity of PLS is its toxicity to animals
c) Anchored to the peptidoglycan layer by the Braun lipoprotein
d) Acts as an effective barrier against many substances sich as lipophilic antibiotics and
other harmful agents
e) Confers only modest structureal strengh on the gram-negative cell
c) Anchored to the peptidoglycan layer by the Braun lipoprotein
63
which of the following is not true about endospores?
a) Mostly from in Gram positive bacteria
b) Lysozyme sensitive
c) Impernable to dyes
d) Have very low water content
e) Some endospored-forming bacteria are serous pathogens of humans and other animals
lysozyme sensitive
63
which part of the structure of bacterial pilolopysaccharise is called endotoxin?
lipid A
63
which of following places Koch’s postulates in the correct order?
Suspected pathogenic microorganisms present in animal with disease, not present in
healthy animals. Microorganisms are isolated; microorganisms are grown in pure culture
and identified; microorganisms are injected into healthy animals to cause a disease;
microorganisms are isolated from the now-sick animal and identified
64
In the laboratory, you modify bacteria by making Mot proteins unfunctional. Which one of the following will be a consequence of having nonfunctional Mot proteins
c) Swimming motility will be affected
64
small acid-soluble proteins (SASPs) protect DNA from ultraviolet light and are found in high numbers within
a) Gram-positive bacteria
b) Endospores
c) Inclusion bodies
d) Gram-negative bacteria
e) Archea
endospores
65
whose experiments finally discounted the theory of spontaneous generation?
Pasteur
66
what temperature is most commonly used in autoclaves to sterilize growth media and other devices prior to experimentation? This temperature should eliminate endospores
121
67
one of the most common inclusion bodies in prokaryotic organisms in poly-b-hydroxybutyric acid (PHB), that is formed from 𝛽-hydroxybutyric acid units. The monomers of PHB polymerize by ester linkage and then the polymer aggregates into granule. The chemical nature of PHB is
lipid
67
cellular inclusions in prokaryotic cells serve to
Store energy rich coumpounds and position cells in the appropriate environment for
survival
68
23) In Griffith's experiment what bacterial structure that defined the virulence of bacteria that caused a disease in the experimental mice and was lethal for them?
capsule
68
22) which of the following is not associated with bacterial capsule?
a) Can be visualized by negative staining with India ink
b) Tightly attached to a cell wall or outer membrane
c) Helps bacteria avoid phagocytosis
d) In most bacteria capsule is made of polysaccharides
e) In most bacteria capsule is made of proteins
e) In most bacteria capsule is made of proteins
69
24) in a given chemical reaction, if the free energy of formation is known for all of the reactants and each of the products, the change in free energy can be calculated for the reaction
True
70
25) You have discovered a new bacterial strain that causes urinary tract infections. Closely related bacterial species cannot cause infections similar to the newly discovered strain. You compare the strains and find that your new strain has many thin (2-10 nm in diameter). Filamentous structures made of protein that extend from the surface of a cell. These structures are present in several hundred per cell. Which of the following is True about these structures
a) these structures allow this bacteria be pathogenic and aid in adhesion to surfaces and
tissue
71
26) If △ 𝐺0′is negative, the reaction is
c) Exergonic and energy will be released
72
27) what is one major difference between anaerobic and aerobic respiration?
electron acceptor
73
28) which one of the following is false about energy generation?
a) During the electron transport process, protons and electrons become physically
separated in the cell membrane
b) The net result of electron transport is the generation of a pH gradient and a an
electrochemical potential across the membrane
c) In electron transport systems, the electron carriers are membrane-associated
d) If a substance is reduced in the electron transport chain, it gains electrons
e) OH- accumulates on the outside of the membrane while H+ accumulated on the inside
e) OH- accumulates on the outside of the membrane while H+ accumulated on the inside
74
29) microbial growth no the two-carbon acetate substrate invokes
a) The citric acid cycle
b) Glyoxylate pathways
c) Fermentation
d) Pentose phosphate pathway
b) Glyoxylate pathways
75
30) for a carbon source, chemoorganotrophs generally use compounds such as
glucose
76
31) the same substance (molecule) can be either an electron donor or an electron acceptor which is explained that not all molecules are strictly one or the other, and each molecule must be ccompared to the other in a pair to determine which is the electron acceptor and which is an electron donor
true
77
33) A beer-making microbiologist noticed that no matter how long the brewing (fermentation) process went, 3% alcohol was the maxumum produced. What changes would you recommend for a higher alcohol yield and increase of fermentation process?
a) Provide more glucose to the yeast during the brewing process
78
34. Which of the following is not associated with the prokaryotic ABC transport system?
a) A substrate-binding protein
b) A membrane-integrated transporter
c) An ATP-hydrolyzing protein
d) System has low substrate affinity
e) Helps microorganisms survive in low nutrient environments
f) Moves nutrients into the cell is against a concentration gradient
has low substrate affinity
78
in e.coli lac permease is associated with all except one of the following
d) Requires energy-rich compound such as phosphoenolpyruvate
79
36. A catalyst of biochemical reactions in the cells
c) Changes the rate of the reaction but does not change the end amount of products
80
37. A potivei change in free energy (△ 𝐺0′) means the reaction needs energy input to occur (called endergonic), whereas a negative △ 𝐺0′ needs no energy input and actually releases excess energy (called exergonic)
true
80
38. Which of the following is not used a long-term energy storage by different microorganisms?
ATP
81
40. Refer to the image below which shows the electron transport chain with terminal electron
acceptor. Which type of cellular respiration is indicated?
anaerobic
82
41. Synthesis of lipid of archaea membranes will involve all except one of the following
a) Formation of ester bonds
b) Formation of ther bonds
c) Presence of isoprene molecules
d) Presence of glycerol
e) Elements for constructing a polar group
formation of ester bonds
83
42. Which of the following is not associated with aerobic chemolitrophs?
organic molecules
83
44. Which one of the following is not a micronutrient?
carbon
83
47. Lysozyme has no destructive effect on cell wall of archaea due to one of the following:
a) Presence of different from bacteria amino acids in the cell wall
b) Presence of pseudomurein
c) Presence of S-layers
d) Presence of different types of glycosidic bonds
e) All of these make archaeal cell wall to be resistant to lysozyme
e) All of these make archaeal cell wall to be resistant to lysozyme
84
46. The electron micrograph of bacterial cells is below. The type of electron microscopy that
was used to obtain this image is
b) Scanning electron microscopy
85
49. How does the proton motive force lead to the production of ATP?
Translocation of three to four protons drives the F0 component of ATPase which in turn phosphorylates one ADP into ATP
86
50. The image below shows the cell layers in
gram + bacteria
87
87
87
87
BIOL 305
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