Micro Biology Exam 2
The MIC of the drug against the microbe is ______.
6.4 μg/ml
The genes of which microorganism(s) are arranged as operons?
Bacteria
The common products of fermentation include ______.
Carbon dioxide, Organic acids, and alcohol
Which is NOT an advantage of fermentation to microbial survival and growth?
Promotes growth in oxygen-rich areas of the host
Which phrase best describes the process of fermentation?
The partial oxidation of glucose
A phage is a virus that infects ______.
bacteria
Which of the following is an excellent target for selective drug toxicity?
bacteria cell wall
An organism that lacks an electron transport chain must derive its energy from ______.
fermentation
Glycolysis rates increase tremendously during _____.
fermentation
Drug failure may be attributed to an infection caused by more than one type of microbe, the inability of the drug to diffuse to the correct location in the body, or to the presence of ________________ bacteria.
resistant
The type of fermentation that produces ethyl alcohol is called 1.(Blank)fermentation, while the type that produces lactic acid is called 2. (Blank) fermentation.
1. Alcohol, and 2. Acid
Which describes a plasmid?
A small circular piece of DNA that replicates its nonessential genes independently of the chromosome.
____________ chemotherapy is the use of chemotherapeutic drugs to control infection and diseases caused by many types of microorganisms.
Antimicrobial
Which genus of fungi is NOT a major source of antibiotics?
Aspergillus
If a particular antimicrobial drug is effective against a variety of different bacteria, it would have a(n) ____________ spectrum.
Broad
A region of some bacterial chromosomes that includes both a set of short repeated sequences and spacer DNA with remnants of bacteriophage and plasmid DNA is called . (Use abbreviation)
CRISPR
Bacteria and archaea store remnants of invading bacteriophage or plasmids at a site called ______.
CRISPR
What type of bacterial cell can be transformed by DNA in the environment?
Competent cell
_______ involves the use of a connecting bridge, _______ requires a bacterial virus vector, and ______ entails transfer of naked DNA.
Conjugation; transduction; transformation
An important means for bacteria to directly transfer resistance plasmids from one cell to another is through the process of
Conjunction
A(n) ______ cell has a separate fertility plasmid, whereas a(n) _____ cell has the F factor incorporated into its chromosome.
F+; Hfr
Which of the following does not require oxygen for the further breakdown of pyruvic acid.
Facultative anaerobes
True or false: Anaerobic respiration and aerobic respiration are the same thing.
False
True or false: Bacterial conjugation is sexual reproduction
False
True or false: In fermentative metabolism, pyruvate is reduced into pyruvic acid.
False
True or false: It is essential to perform an antimicrobial susceptibility test for all infectious agents.
False
What pathway can be used by facultative anaerobes if oxygen is not readily available?
Fermentation
_________ transduction transfers random pieces of host cell DNA, whereas ________ transduction transfers pieces next to the prophage insertion site in the bacterial chromosome.
Generalized; specialized
Regardless of lactose levels, the lac operon remains in the "off" position if what nutrient(s) is present?
Glucose
In CRISPR technology, the targeted gene is recognized by a molecule called
Guide RNA
For which of the following reasons would antimicrobial susceptibility testing be performed?
If the pathogen commonly shows resistance to the antibiotic
Which strategy is used to prevent colonization of biomaterials that are susceptible to biofilm contamination?
Impregnation of biomaterials with antibiotics prior to insertion
Which of the following is NOT a general mechanism of antimicrobial drug actions?
Inhibiting electron transport systems
Which of the following are general mechanisms of antimicrobial drug actions?
Inhibiting nucleic acid structure or function, Inhibiting cell wall synthesis, Inhibiting protein synthesis, Interference of cell membrane structure and function
During fermentation, which electron carrier is made available to reenter glycolysis so that ATP production can continue in the absence of oxygen?
NAD
As a result of fermentation, ______ are produced that are recycled to enter ______.
NADs; glycolysis
Bacterial and archaeal genes are arranged into ________
Operons
Which of these antibiotics would be a poor choice to treat an infection caused by Staphylococcus aureus?
Penicillin G
Transposons are linked to which of the following in bacteria?
Phenotypic changes in colonies, Intermicrobial transfer of drug resistance, and Replacement of damaged DNA
Donor and recipient bacterial cells are connected by a(n) ___________ during conjugation.
Pilus
Which of the following statements are correct regarding the Kirby-Bauer data in the table?
Polymyxin is not a good choice, as it is intermediate in effectiveness and Tetracycline is extremely effective against S. aureus and would be a good choice.
What is commonly shared between bacteria through the process of conjugation?
Resistance plasmids and Genes for virulence factors
Examine the data in the table regarding the susceptibility of Staphylococcus aureus to erythromycin. Which of the following statements is correct?
S. aureus responds in an intermediate manner and erythromycin would not be effective in treating this infection.
Which type of transduction involves temperate phages that incorporate their genome into the bacterial host chromosome before carrying pieces to another host cell?
Specialized transduction
The two major bacterial sources of antibiotics are the genera __________ and _____________- .
Streptomyces and Bacillus
Which oxidized compound(s) can be used as a final electron acceptor in anaerobic respiration?
Sulfate (SO42-), Nitrate (NO3-), and Carbonate (CO33-)
Two antibiotics are being considered for a patient. The causative microbe is susceptible to both antibiotics. One drug has a therapeutic index of 1.1 and the other has a therapeutic index of 10. Which is the best choice?
The drug with the therapeutic index of 10
How do an Hfr cell and an F+ cell differ?
The plasmid is integrated into the chromosome of an Hfr cell but not in an F+ cell.
Which type of horizontal gene transfer has been linked to the virulence of bacteria such as Clostridium, Streptococcus pyogenes, and Corynebacterium diphtheriae?
Transduction
________ are DNA sequences that can switch sites in a genome and lead to changes in the genotype.
Transposons
What is drug resistance?
When microbes begin to tolerate an antimicrobial agent at a level which would normally be inhibitory
Starting with pyruvic acid, which two types of fermentation can occur?
acidic fermentation, and alcoholic fermentation
The presence of a CRISPR region in a bacterial chromosome is a(n) _____ to the host because ______.
advantage; it allows the microbe to keep a record of previous phage invasions
Which type of chemotherapy involves the use of chemotherapeutic drugs to control infection and diseases caused by many types of microorganisms?
antimicrobial chemotherapy
A(n) ______ is a bacterial virus involved in _______, a means of horizontal gene transfer.
bacteriophage; transduction
The active part of the penicillin and cephalosporin structure is the ______ ring.
beta-lactam
Complex polysaccharides can be used as a source of carbon and energy by ______.
breaking them down into their component sugars
An antimicrobial drug that is effective against a variety of different bacteria would have a ______ spectrum.
broad
Phase variation occurs when Streptococcus pneumoniae produce a ________________
capsule
Which oxidized compound can be used as a final electron acceptor in anaerobic respiration?
carbonate (CO33-), sulfate (SO42-), and nitrate (NO3-)
Penicillin derivatives were developed that overcame the limitations of the original penicillin. These derivatives resulted from ______.
chemical modification
In this Kirby Bauer test with E. coli, the bacterium is resistant to ______.
chloramphenicol and oxytetracycline
A bacterial cell that can accept soluble DNA from the surrounding environment is described as
competent
Besides glucose, which of the following compounds can be used as a source of energy and building blocks?
complex polysaccharides, fats, and proteins
The binding of lactose to the lac repressor results in ______.
conformational change to the lac repressor
A pilus connects two bacterial cells to facilitate the transfer of genetic material during the process of
conjugation
In bacteria, horizontal gene transmission through a pilus is called
conjugation
Which organisms carry out fermentation?
facultative anaerobes, and aerotolerant anaerobes
In CRISPR, the gene sequence to be altered is specified by a _____ RNA.
guide
n CRISPR, the gene sequence to be altered is specified by a _____ RNA.
guide
When considering antibiotics for patient use, it is best to use a drug with a _____ therapeutic index.
high
Peptidoglycan in the bacterial cell envelope is an ideal target for antibiotics because ______.
human cells do not have peptidoglycan, and cell wall synthesis inhibitors are selectively toxic to bacteria
Penicillins exhibit low toxicity for human cells because ______.
human cells do not synthesize peptidoglycan, the target of penicillins
In the presence of glucose and lactose, the lac operon will be _____.
inactive
A CRISPR region in a bacterial chromosome offers an advantage to the host because it allows the ______.
microbe to keep a record of previous attacks
Biofilm infections are most likely to be found in or on which of the following?
middle ear and urinary catheter
A ______-spectrum drug is effective against a limited array of microbe types. Multiple choice question.
narrow
If an antimicrobial drug is only effective against gram-negative bacteria, it has a(n) ______ spectrum.
narrow
In the absence of lactose, the lac repressor binds to the ______________
operator
The lac repressor binds to the ______ in the absence of lactose.
operator
An organism will gets its energy from fermentation when ______.
oxygen is absent from its environment and it does not have an electron transport chain
The beta-lactam ring is the active part of ______ and cephalosporin structure.
penicillin
Which term refers to bacteria that slow or stop their metabolism so that they cannot be harmed by an antibiotic?
persisters
The ability of Neisseria gonorrhoeae strains to produce attachment fimbriae is an example of ______.
phase variation
The process of bacteria turning on or off a group of genes that changes its phenotype is called ______________ __________________
phase variation
Phase variation is a type of ________ variation.
phenotypic
In bacteria and archaea, CRISPR areas of the genome are a storage site for ______.
pieces of DNA from phage or plasmids
Donor and recipient bacterial cells are connected by a(n) _____________ during conjugation.
pilus
A small circular segment of DNA found in the cytoplasm of bacteria that is capable of independent replication and usually contains nonessential genes is called a(n)
plasmid
A CRISPR region of a bacterial chromosome is comprised of ______.
spacer DNA with pieces of bacteriophage or plasmid and short sequences repeated many times
Binding of lactose to the lac repressor results in transcription of the ______.
structural genes
In the CRISPR technique, a guide RNA ______.
targets the gene sequence to be modified
The production of toxins in some virulent strains of bacteria has been linked to bacteriophage genes that have been transferred by _____________.
transduction
Jumping genes", or , are gene sequences that can lead to changes in genotype within a cell or between cells.
transposons
What has been linked to changing morphology in bacteria, the intermicrobial transfer of drug resistance, and the repair of damaged DNA in bacteria?
transposons
True or false: One reason that antibiotic treatment failure occurs is because the drug could not diffuse into the infected body part
true
An excellent cellular structure that can be a target for selective drug toxicity is the bacterial cell
wall
Under which circumstance might a microbe be intrinsically resistant to an antibiotic?
when the microbe produces the antibiotic
