Final Flashcards
(145 cards)
1
Q
If the broth in Pasteur’s swan-necked flask experiment had contained endospores, which of the following results might he have obtained?
A
The broth would seem sterile after boiling but would soon develop bacterial growth
2
Q
In nature, bacteria: (all answers are correct)
A
- Often grow in close association with many other kinds of organisms
- frquently synthesize structures such as slime layers
- Often produce antibiotics to inhibit the growth of competitors
- may adhere to surfaces by means of pili and slime layers
3
Q
Electron microscopes differ from light microscopes in that
A
- electrons replace light
- resolution is higher
- magnification is higher
- electromagnets replace glass lenses
4
Q
Place steps of Gram stain in correct order
A
- crystal violet
- iodine
- alcohol-acetone
- safranin
5
Q
Chemoheterotrophs
A
- use preformed organic molecules as an energy source
- use preformed organic molecules as a carbon source
6
Q
Which of the following best describes how penicillin effects peptidoglycan?
A
Prevent cross-linking of adjacent glycan chains
7
Q
Agar replaced gelatin as the gelling (solidifying) agent for media because
A
- agar is solid at body temp
- much fewer bacteria can break down agar than gelatin
8
Q
Sugar or salt can be used for food preservation because
A
- they create a hypertonic environment, unfavorable for bacterial growth
- they may cause plasmolysis
- they dehydrate cells
9
Q
Arrange the general size of microbes from the largest to smallest:
A
- Helminth
- Protozoa
- Bacteria
- Viruses
- Viroids
10
Q
The outbreak of measles within the last few years was due to
A
a decline in vaccination of children in the previous years
11
Q
Negative staining is commonly used to determine if bacterial cells have
A
capsules
12
Q
All of the following are factors that account for the emergence of new diseases in developed countries EXCEPT:
A
parents do not have their children vaccinated
13
Q
Check all statements that apply to the bacterial cytoplasmic membrane
A
- Proton motive force
- Barrier to large compounds
- aquaporins
14
Q
A species of bacteria that is fastidious is least likely to be able to grow on which of the following media?
A
glue-salts agar
15
Q
Facilitated diffusion and active transport
A
both transport molecules into or out of a cell
16
Q
In the growth curve of a bacteria population, the bacteria are rapidly increasing in number in the
A
exponential (log) phase
17
Q
In figure 6.3, which tube shows the expected growth pattern for a facultative anaerobe
A
b. a build up at the top but spread between the liquid
18
Q
Ultraviolet radiation at the bactericidal wavelength destroy bacteria by
A
damaging nucleic acid
19
Q
Pasteurization
A
is the use of heat to reduce numbers of pathogenic/spoilage bacteria in a food item to a safe level
20
Q
Which of the following most likely contains human pathogens?
A
Mesophiles
21
Q
A high-solute, or ___ environment causes plasmolysis which damages microbial cells
A
hypertonic
22
Q
Which of the following stains is/are considered differential?
A
- Acid-fast stain
- gram stain
23
Q
Antibiotic Killcillin targets 50S ribosome subunit and will kill
A
bacteria
24
Q
If you wanted to increase your chances of isolating a member of the Archaea (rather than a member of another domain)
A
A 95 degree celsius hot spring in yellowstone national park
25
The idea of spontaneous generation postulated that
living organisms could spontaneously arise from non-living material
26
The opposite results obtained by scientists apparently doing the same experiments in investigating spontaneous generation
all of the choices are correct
27
Order the following situations from highest to lowest requirements of microbe-free environments:
1. Open heart surgery
2. pharmaceutical manufacturing facility
3. food production facility
4. kitchen counter
5. bathroom counter
28
A microbiologist obtained two pure isolated biological samples: one of a virus and one of a viroid. The labels came off during a move from one lab to the next however the scientist felt she could distinguish between the two samples by analyzing for the presence of a single type of molecule would she be looking for to differentiate between the two?
protein
29
Which of the following are found in gram positive cells but not gram negative cells?
teichoic acids
30
A species of bacteria lacks superoxide disputasse and catalase. Which of the following groups does this species of bacteria likely belong to?
obligate anaerobes
31
Bacteria on fish caught in the arctic ocean would
- continue to grow while the fish is in the refrigerator
| - be psychrophiles
32
a. sterilization
b. disinfection
c. antispesis
d. bacteriostasis
e. sanitation
1. removing pathogens to meet public health standards
2. inhibiting growth of bacteria
3. removing all microbial life forms
4. removing pathogens from living tissues
5. removing pathogens from inanimate objects
- sanitation (1): removing pathogens to meet public health standards
- bacteriostasis (2): inhibiting growth of bacteria
- sterilization (3): removing all microbial life forms
- antispesis (4): removing pathogens from living tissues
- Disinfection (5): removing pathogens from inanimate objects
33
Which is NOT true about smallpox?
-It still occasionally occurs in third world countries
34
The resolving power of a microscope is describe as the ability of the microscope to
separate clearly two objects that are very close together
35
A microbe is discovered growing near a deep sea thermal vent. When researchers bring a sample up to the surface and try to grow t in a lab at room temperature in a normal incubator, they are unsuccessful. Why?
All of the answers
36
To obtain an effective concentration of chlorine when using household bleach, a 1:100 dilution is made. This means that ___ mL of bleach is added to ___ mL of water
1,99
37
Boiling is not reliable for sterilization because
Heat-resistant endospores are unaffected
38
Which of the following is found exclusively in prokaryotic cells?
Endospore
39
Which is (are) true concerning the cell wall of all prokaryotes?
- it prevents the bacteria from bursting
| - it determines the shape of the bacteria
40
A sterile item is free of:
- endospores
- archeae
- bacteria
- prions
- viruses
41
Which DOES NOT describe protozoa correctly?
ingest inorganic materials as main food source
42
The decimal reduction time is the time it takes to kill 90% of a given bacterial population under certain conditions. If 90% of a population of 10,000 bacteria is killed in 5 minutes, how long would it take to reduce the population to 10 cells?
15
43
Describe:
a. viruses
b. bacteria
c. archaea
d. protozoa
e. viroids
- viruses (1): made of nucleic acids and proteins
- bacteria: Single-celled organisms with peptidoglycan cell walls but without a nucleus
- archaea: single-celled organisms living in extreme environments and without a nucleus
- protozoa: single-celled organisms with a true nucleus
- viroids: naked nucleic acids
44
Which of the following is not a sterilization method?
Pasteurization
45
Which of the following pairs is most closely related and correctly written?
Staphylococcus aureus and Staphylococcus epidermis
46
MacConkey agar contains bile salts and dyes that inhibit Gram-positive organisms and Gram0negative cocci, making it ___; it also contains a pH indicator that turns pink-red when lactose in the medium is fermented, making it ____.
Selective, differential
47
Organisms may derive energy from
- metabolizing chemical compounds
| - sunlight
48
In the presentation of Current Microbiology News, "Hygiene Hypothesis" was mentioned in relation to normal micro biome. Which statement best describe the Hygiene Hypothesis?
Early exposure to microbes in the environment allow immune system to be trained and developed well in children
49
If you remove the glycoocalyx of a bacterium, the organism would no longer be able to
survive in hypotonic solutions
50
Haemophilus influenza is a gram-negative coccobacilius. If you looked as a gram stained culture using a light microscope, you would expect to see
pink, very short rod
51
Consider how an aerobically respiring bacterial cell uses glycolysis, the TCA cycle, and oxidative phosphorylation to break apart and oxidize glucose. What are three main benefits these central metabolic pathways yield to the cell?
ATP
reduced electron carriers
precursor metabolites
52
```
Functions of the following
tRNA
mRNA
rRNA
miRNA
```
tRNA: Carries amino acids to the growing peptide chain during translation
mRNA: contains the genetic information decoded during translation
rRNA: components of ribosomes
miRNA: regulates gene expression
53
```
Functions of the following:
DNA gyrase
primase
helicase
okazzaki fragments
DNA ligase
```
- DNA gyrase: enzyme that temporarily breaks the strands of DNA relieving the tension caused by unwinding the two strands of DNA helix
- Primase: Enzyme that synthesizes small fragments of RNA
- Helicase: Enzyme that unwinds DNA helix at the replication fork
- Okazzaki fragments: Nucleic acids produced during discontinuous synthesis of lagging strand of DNA
- DNA ligase: Enzyme that joins two DNA fragments together forming a covalent bond btw the sugar and phosphate residues`
54
Which of the following statements about the figure below are TRUE?
-The organism shown on the agar plate is likely a Pseudomonas species
55
Which of the following are correct regarding Restriction Enzymes?
- DNA fragments produced by restriction enzymes can be ligated together
- They evolved as a defense mechanism against bacteria
56
Place the steps of F plasmid transfer in order
1. F plus makes contact with recipient cell
2. one strand of the f plasmid is cut at the origin of transfer
3. Single-stranded is transferred to the recipient
57
Which of the statements about DNA and RNA in prokaryotes and eukaryotes are FALSE?
- Eukaryotic mRNA is typically polycistronic
| - RNA polymerase requires a primer
58
Which of the following would be the correct scientific name?
Homo sapiens (all italicized)
59
Order the events in the oxidation of glucose
1. Phosphorylation of glucose
2. Formation of pyruvate
3. Formation of acetyl-coA
4. TCA cycle
5. Oxidative phosphorylation
60
Stop codons for DNA translation include
- UAG
- UAA
- UGA
61
During enzymatic run, a non-competitive enzyme inhibitor would bind to the enzyme's ___.
-allosteric site
62
PCR can be used to
All of these
63
A culture of E. coli is irritated with UV light. The highest frequency of mutations would be obtained if after the irridation, the cells were immediately
placed in the dark
64
Which is true about a crown gall tumor?
- requires a plasmid
- is a bacterial infection of plants
- due to incorporation of bacterial plasmid DNA into the plant chromosome
- produces a large amount of opines that neither the plant nor bacteria synthesizes
65
Which of the following describe the ames test correctly
- is a method that uses bacteria to test if a given chemical can cause mutations in DNA
- The test uses bacteria that cannot make their own histidine
66
The codon 5' UGC 3' on mRNA encodes for cysteine. Which sequence represents an anticodon from the 5'-3' direction?
GCA
67
After the completion of DNA replication and cell division in prokaryotic cells,
- both daughter cells have identical copies of DNA
| - each daughter cell contains DNA with one newly synthesized DNA strand and one original parental strand
68
Taxonomic principles with definitions:
1. Phylogeny
2. Identification
3. Nomenclature
4. Classification
- Phylogeny: Evolutionary relatedness of organisms
- Identification: the process of characterizing an isolate to determine the group to which it belongs
- Nomenclature: the system of assigning names to organisms
- Classification: the process of arranging organisms into similar or related groups
69
Concerning catabolism and anabolism,
- the energy gathered in catabolism is utilized in the anabolism
- the intermediates of one serve as the reactants in the other
70
Which organisms are most closely related?
B. cereus and S/ aureus
71
Compound A lost a pair of electrons to compound B during a chemical rxn..
Compound A is being oxidized and compound B is being reduced
72
Match the following to examples:
1. Chemoautotroph
2. Photoheterotroph
3. Chemoautotroph
4. Chemoheterotroph
1. Chemoautotroph: Cyanobacteria
2. Photoheterotroph: green, purple non sulfur bacteria
3. Chemoautotroph: iron oxidizing bacteria
4. Chemoheterotroph: fungi`
73
Match following to definitions:
1. Missense mutation
2. Nonsense mutation
3. Frameshift mutation
4. Silent mutation
1. Missense mutation: Change in DNA codon results in a change in amino acid
2. Nonsense mutation: Sense codon is converted to a stop codon
3. Frameshift mutation: Deletion or insertion of nucleotides not divisible by three
4. Silent mutation: Change in DNA codon doesn't result in a change in AA
74
Most vectors used today have a multiple cloning site. The reason for this is
to allow DNA fragments with different restriction sites to be cloned
75
Arrange the following in the proper sequence in which they occur during a single PCR cycle
1. Heat separation of strands of target DNA
2. Complementary base pairing between primers and target DNA
3. Addition of DNA nucleotides by Taq DNA polymerase
76
A pathogenic strain of E. coli acquired a toxin from another bacterial species. However, there was no direct contact btw the bacterial cells, this is due to:
- transformation
| - transduction
77
Identify bacterium with: stains purple in the gram stain, produces bubbles when placed in hydrogen peroxide and coagulate plasma
Staphylococcus aureus
78
Which of the following are valid concerns for genetic engineering and other DNA technologies>
- Spread of herbicide resistant gene to weeds
- allergens
- misuse of personal DNA sequence data
79
Which change in gene's DNA sequence would have the least effect on the eventual AA sequence produced from it?
Addition/deletion of three consecutive nucleotides
80
In conjugation the donor cell is recognized by the presence of
an F plasmid
81
If the mRNA, 5' some long protein 3' is translated, what is the codon that corresponds to the third AA in the resulting protein?
CGC
82
After a few weeks, you see a contaminant growing on your plates, assuming is not digesting the afar itself, which of the following is most likely your contaminant?
Photoautotrophic species of bacteria, archaea or protists
83
Which is true of the transitional step in the central metabolism?
- the 2-C acetyl group is joined with coenzyme A to form acetyl-coA
- CO2 is removed from pyruvate
- Electrons are transferred to NAD+, reducing it to NADH+ H+
84
Which is not commonly found in a cloning vector?
Restriction enzyme genes
85
If meghylguanine replaces guanine in a DNA strand with the sequence 5'CGA3', which of the followings are possible complementary DNA strand after replication?
- 3'GCT5'
| - 3'GTT5'
86
In the figure, the probes in A do not bind to the denatured DNA because
they are not complementary to the unknown DNA
87
The process of DNA translation includes all but
transformation
88
Order the following events in translation
1. fMethionine tRNA binds AUG codon at the P site
2. A tRNA with AA arrives at the A site
3. Peptide bond formed btw AA on P and A sites
4. A tRNA moves to the E site
5. Release factor arrives at A site
89
Consider the figure below. Bacteria containing the plasmid shown in panel A would generate ___ colonies on medium containing x-gal, while those in panel B would generate ___ colonies.
blue; white
90
Removing the ETC of E. coli would
prevent oxidative phosphorylation
91
Which of the following best described enzymes?
- enzymes dont change after a rxn
| - enzymes reduce EA
92
Which of the following correctly describe the degeneracy of the genetic code?
- An AA can be coded by several codons
- The third position of the codon is sometimes not important in determining which AA a codon encodes
- More than one codon can code for an AA
93
In aerobic respiration, the final electron acceptor in the ETC is
O2
94
What enzyme separates thymine dimers?
photolyases
95
The lac repressor in the absence of lactose
active and can bind to the operator
96
Which is not a step in generating recombinant DNA molecules?
RNA polymerase is used to copy the gene of interest in genomic DNA
97
Which is not a reason why rRNA sequences are so useful in microbial classification and identification?
The sequences are very different, which makes it easier to distinguish btw closely related microbes
98
The Gram-positive rod that is also acid-fast and is a human pathogen is
Mycobacterium tuberculosis
99
All of the following fungal spores are produced sexually except
- Chlamydospores
| - Arthospores
100
Place the steps in interferon (IFN response in the correct order
1. A cell detects viral RNA and produces IFNs
2. IFN diffuses out of the infected cell and attached to receptors on healthy neighbors
3. IFN stimulates health neighboring cells express inactive antiviral proteins
4. Inactive antiviral proteins become activated by the presence of viral dsRNA in the newly infected cell
5. Activated antiviral proteins degrade mRNA
101
Which of the following is/are obligate intracellular parasites
Chlamydia and Rickettsia
102
Which apply to a primary antibody response to a T-dependent antigen?
- Takes 10-14 days to build a substantial amount of antibodies in the bloodstream
- Produces mainly IgM antibodies but undergoes class switching to other classes near the end of the response
103
T cells and B cells develop from stem cells in red bone marrow, but T cells mature in the ___ while B cells mature in the ___
Thymus, bone marrow
104
What definitely set viruses apart from other organisms?
- Viruses replicate by assembly
| - Viruses are not made of cells
105
Which of the following statements regarding lichens is false?
Lichens represent a parasitic relationship btw fungus and an alga or cyanobacterium
106
Match immunoglobulin class on left with characteristics on right
1. IgM
2. IgG
3. IgA
4. IgE
1. IgM: Pentamer, first class of antibody produced in the primary response
2. IgG: Most abundant in the blood serum, cross placenta and offer protection to developing fetus
3. IgA: most abundant produced but most secreted to mucus, tears and saliva. Also found abundant in milk
4. IgE: Binds to mast cells and basophils and involved in many allergic rxns
107
Which is NOT a characteristic of B cells?
They recognize antigens associated with MHC I
108
Members of this group of micorbes can break down glycogen deposited in the vaginal lining in response to estrogen. This helps to drop the pH in the area, preventing infections.
Lactic acid bacteria
109
The earliest oxygenic phototrophs are thought to be
cyanobacteria
110
Which statement about prions are correct
- Prion proteins are normally found within the body as PrPc (cellular prion protein) and are not harmful
- Prions are proteinaceous infectious particles
- Abnormal prion can change to normal prion into an abnormal prion causing a chain rxn
111
Match lymphocyte development with its description
1. Naive
2. Activated
3. Immature
4. Effector
5. Memory
1. Naive: have antigen-specific receptors
2. Activated: able to multiple bc they have encountered an antigen they recognize and have received signal confirming that the antigen requires a response
3. Immature: lack fully developed antigen-specific receptors
4. Effector: descendants of activated lymphocytes that are armed with protective abilities
5. Memory: long-lived descendants of activated lymphocytes
112
Viruses may not be cultivated in
cell free complex media
113
Are all fungi detrimental for other organisms?
No, sometimes good, sometimes bad
114
The primary purpose of asexual spores is ___, and the primary purpose of sexual spores is ___.
dispersal, survival or dormancy
115
Valley fever is
- a fungal disease
| - cause by coccidioides sp.
116
Viroids can best be described as:
naked infectious RNA, which can self-replicate in a host cell
117
The ability to exist as either a trophozoite or a cyst is characteristic of many
protozoa
118
Match descriptions with correct group of viruses
1. Retroviruses
2. Single-stranded (+) sense RNA viruses
3.
4. Single-stranded DNA viruses
1. Retroviruses: Carry an RNA-dependent DNA polymerase in their virions
2. Single-stranded (+) sense RNA viruses: viral genome can be translated directly by host ribosomes
3.
4. Single-stranded DNA viruses: Copies of progeny viral genome are made from a dsDNA template
119
Dimorphic fungi
- often associated with disease in humans and animals
| - are strictly hyphae
120
The best possible analogy for the way in which V, D and Antibody gene segments get put together to create the diversity possible in hyper variable regions is
BINGO GAME
121
The Gram neg bacterium that can break down urea and causes stomach ulcer is
Helicobacter pylori
122
Members of the family Enterobacteriaceae
- include e. coli, enteribacter, salmonella and shigella
- often reside in the intestinal tract of humans and animals
- are facultative anaerobes
123
A vision is composed f
protein, either RNA or DNA and possibly lipid
124
Match statement to decritption of possible end results of antibody binding antigen
1. Neutralization
2. Complement system activation
3. Cross-linking
4. Antibody-dependent cellular cytotoxicity (ADCC)
5. Opsonization
1. Neutralization: Antibodies bind to the surface receptors on microbe to prevent attachment to the host
2. Complement system activation: Immune complexes activate complement proteins
3. Cross-linking: Formation of large Ab-Ag complexes as a result of the Ab binding two separate antigens
4. Antibody-dependent cellular cytotoxicity (ADCC): IgG molecules attach to a cell targeting it for attack by a NK cell
5. Opsonization: Coating of microbe with antibody to enhance phagocytosis
125
A macrophage kills by ___ while a neutrophil kills by ___?
Ingesting microbes and destroy them internally, ingesting microbes and also releasing toxic granule component
126
Fever
- enhances bacterial growth
- inhibits bacterial growth
- speeds up the body's rxns
127
Which statement does not describe activation of innate immune responses by pattern recognition receptors (PRRs) correctly?
PRRs recognize molecules derived only from pathogens outside of a cell
128
Several inherited deficiencies in the complement system occur in humans. Which of the following would be the most severe
deficiency of C3
129
Match bacteria with diseases they cause:
1. Cammpylobacter jejuni
2. Treponema pallidum
3. Bordetella pertusis
4. Helicobacter pylori
5. Neisseria gonorrhoeae
6. Bacillus anthracis
1. Cammpylobacter jejuni: Diarrhea
2. Treponema pallidum: Syphilis
3. Bordetella pertusis: Whooping cough
4. Helicobacter pylori: Stomach ulcer
5. Neisseria gonorrhoeae: Gonorrhea
6. Bacillus anthracis: Anthrax
130
A bacterium being examined in a micro lab is found to be lysogenized by phange A. Which is true?
the bacterium is immune to reinfection by phage A but susceptible to infection by phage B
131
Which is not a reason that oncogenic viruses contribute to cancer development
Viruses may carry tumor suppressor gene
132
Match terms with involvement in innate immunity
1. skin
2. mucus
3. respiratory tract
4. Leukocyte
5. Lactoferrin
6. granuloma
7. cytokine
1. skin: keratin
2. mucus: lysozyme
3. respiratory tract: mucociliary escalator
4. Leukocyte: neutrophil
5. Lactoferrin: chemical defense
6. granuloma: macrophage
7. cytokine: interleukin
133
Which statement regarding bacteria is false?
lactobacilli can grow easily on a nutrient agar in the presense of oxygebn
134
which of the following about innate immunity is true
toll-like receptors recognize molecules derived from pathogens
135
Why are eukaryotic pathogens of animals more difficult to treat than prokaryotic pathogens?
Eukaryotic pathogens more similar to host cells
136
Which of the following are likely to live on dry and salty surfaces?
- micrococcus
| - staphylococcus
137
Which of the following events does not occur after t-cell activation
neutrophils become more powerful
138
Which is false about fungi?
fungi can be photosynthetic
139
Influenza viruses bud from the host cell. Based on this, the viruses most likely
are enveloped
140
Skin and mucous membranes
- contain antimicrobial secretions
- are the first line of innate immunity
- act as physical barriers to infection
141
Algae differ from protozoa in that
algae carry out photosynthesis while protozoa cannot
142
Steps of B cell activation
1. B cell receptors bind to antigens
2. Antigens are internalized and digested into peptide fragments
3. Peptide fragments are displayed on MHC class II molecules
4. T helper cells recognize antigen-MHC complexes
5. T helper cells deliver cytokines to naive B cells
6. Activated B cells proliferate and differentiate into plasma cells and memory cells
143
Steps of viral infection
1. Entry
2. uncoating of capsid
3. biosynthesis of proteins and nucleic acids
4. vision assembly
5. release
144
Which is not a component of innate immunity
antibody
145
If your cell mediated immune response were compromised, which of the following would happen?
you would be more susceptible to infections by viruses
