Medical Microbiology review 3
Which of the following is not a characteristic of Okazaki fragments?
They are longer in eukaryotic cells
Which of the following is True concerning the structure and function of enzymes?
After an enzyme has catalyze do reaction, it resumes its original shape and can interact with a new substrate molecule.
Honey can be stored at room temperature for long periods of time because it
Is hypertonic
Bacteria acquire new DNA from the environment in the process of
Transformation
Modified corn strains that produce an insect toxin from a bacterial gene are an example of
Transgenic organisms
Antiviral medications can best be described as
Extremely narrow spectrum synthetic antimicrobials
Alcohols are used for
Both antiseptic and disinfection
Which of the following items is Not a part of the name of a restriction enzyme
The Gram reaction of the source bacterium
Synthetic nucleic acids are useful as
DNA probes, primers, and antisense RNAs
Which of the following types of antimicrobial agent has the narrowest spectrum of action
Antivirals
Isomerases catalyze reactions in which
Atoms in biomolecules are rearranged
Which of the is found at the 5' end of a DNA strand
A phosphate group
Which statement about quaternary ammonium compounds is CORRECT
They are not effective against pseudomonas aeruginosa
If a cell reverses the process of beta-oxidation, which of the following molecules will it make
Fatty acids
A codon is a particular combination of three nucleotides. Therefore, there are ______ possible combinations of the nucleotides A,C,G, and T.
64
If all of the following DNA fragments were analyzed on an electrophoresis gel, which one would migrate farthest from the negative electrode
250 base pairs
Some of the strongest opposition to the application of recombinant DNA technology concerns
Modification of food crops
During ______, a new peptide bond is formed with the amino acid located in the A site
Translation elongation
The AUG codon function in coding for the ammino acid methionine and as a
Start signal
Dedication is primarily effective against
Vegetative bacteria
If a researcher used E. coli DNA polymerase instead of T. aquaticus DNA polymerase in the PCR procedure, what would be the result
DNA replication would stop after one cycle
An ancient application of biotechnology is
Production of cheese
Which of the following would be an appropriate sequence of temperatures for PCR
94, 65, 72 degrees Celsius
The assembly of carbon dioxide and water into carbohydrates occurs in the process known as
Photosynthesis
Which of the following is a target of pasteurization
Brucella melitensis
DNA fingerprinting can be used
For forensics and detection of unculturable organisms
Medications which should not be prescribed for a pregnant woman include
Sulfanamides and tetracyclines
Recombinant DNA technology can be most accurately defined as the
Deliberate modification of the genome of an organism for practical purposes
Disruption of the normal microbiota can result in infections caused by which of the following
Candida albicans,Microbacterium, and Clostridium difficile
Which of the following microbes has been genetically engineered to contain a protein that helps protect crops from freezing
Pseudomonas
Small circular DNA autonomously replicating molecules with several restriction sites and a " marker" to trace their location are commonly called
Vectors
Synthetic antimicrobial that block protein synthesis by binding to the mRNA are
Antisense nucleic acids
All of the following are ways in which cells regulate metabolism EXCEPT
Use of the same coenzymes for anabolic and catabolic reactions that share substrate molecules
The chemical agent known as "quats" are used for
Disinfection
Which of the following has been genetically modified to stop the spread of a human disease
Aedes aegypti
A new antibacterial medication prevents the assembly of ribosomes on mRNA. The new medication would be
Either an antisense RNA or a type of oxazolidinone
The compound ethylene oxide is used in
Sterilization
Most broad spectrum antibiotics act by
Inhibiting protein synthesis
How does resistance to drugs spread in bacterial populations
Both horizontal gene transfer and the growth of biofilms spread drug resistance
The conversation of ammino acids to carbohydrates is an example of
Gluconeogensis
DNA sequences known as transposons contain
F+ plasmids
What are the "sticky ends" produced by some restriction enzymes
Sticky ends are short single-strand ends of DNA able to hydrogen bond with complementary strands
Injecting DNA into cells can be accomplished using
Micropipetes, or compressed air and gold beads
The events of _______ are initiated at sequences called origins
DNA replication
The bacterial chromosome is
Both circular and found in a nucleoid
Which of the following would be used to sterilize a mattress
Ethylene oxide
Cells must be naturally or artificially "competent" for which of the following events to occur
Transformation
Which of the following is not involved in the regulation of the lac operon
An iRNA
Which of the following statements is true of disinfectants
They are used on inanimate surfaces
Which of the following recombinant tools is NOT used in DNA fingerprinting
Reverse transcription
The E test determines which of the following
Both susceptibility and MIC ( minimum inhibitory concentration)
A medication that inhibits synthesis of ergosterol would be effective in treating
Fungal infections
The DNA sequence of a portion of gene in a wild type organisms is TTACCATATTCACC, and the corresponding peptide sequence is Leu-Pro-Tyr-Ser-Pro. The corresponding gene fragment in a phenotypic variant of the organism is TTACCATTCACC and the peptide sequence is Leu-Pro-Cys-Ser-Pro. This is an example of an ________ mutation (type) resulting in a _________ mutation (effect)
Base substitution; missense
In southern blotting, DNA molecules are immobilized on
Nitrocellulose membranes
Subunit vaccines are safer than traditional vaccines because they
Are acellular and do not pose a risk for causing the disease
The mechanism of action of the antibiotic vancomycin is
Inhibition of cell wall synthesis
Which of the following is necessary to produce an "expression " library representing the active genes of an organism
Reverse transcriptase
Broad spectrum synthetic antimicrobial swerve discovered by
Gerhard Domagk
Why is bacillus stearothermophilus useful as an indicator of sterility
It forms endospore said, among the most hardy of microbial contaminants
Seventy-percent alcohol is effective against
Enveloped viruses
Alterations in the structure of which of the following are an important aspect of gram- negative bacterial resistance to antimicrobial drugs
Porins
Beta oxidation produces a substrate of the
Kreb cycle
Codons are recognized by
tRNAs
The endospore said of which of the following are used to measure the effectiveness of autoclave sterilization
Bacillus stearothermophilus
In reactions catalyzed by oxidoreductases an electron donor is
Oxidized
Formaldehyde must be handled with greater care than gluteraldehyde because it is
A carcinogenic gas
During elongation a charged tRNA first enters the ribosomal _______ site and then moves into the __________ site.
A , P
A germistatic agent would be effective on
Vegetative bacterial cells
Which of the following antimicrobial agents is the most toxic to humans
Ethylene oxide
Which of the following procedures might be used to detect the presence of genetic sequences of a virus in a sample
Southern blotting or PCR
Which of the following is involved in translation
mRNA, rRNA, and tRNA, are all involved
DNA encoding a normal gene is inserted into cells from a patient with a defective form of the gene. Recombinant cells are identified and isolated, and returned to the patient's body. This is an example of
Gene therapy
Which of the following interferes with cell wall synthesis by blocking alanine bridge formation
Both cycloserine and vancomycin
Which of the following occurs in eukaryotes but Not in prokaryotes
Polyadenylation
Which of the following is used for microbial control in fresh fruits and vegetables
Gamma rays
What repair mechanism is most likely involved in repairing DNA damage caused by ionizing radiation
SOS response
Which of the following is an example of sanitization
A public toilet is treated with disinfectants
Which of the following antibiotics disrupts cytoplasmic membrane function
Amphotericin B
In coagulation, F+ cells
Contain an F plasmid
Pentamidine is an example of an antimicrobial that
Binds to DNA
Which of the following types of radiation causes the formation of damaging chemical bonds in DNA
Ultraviolet light
Which of the following contributes to the packaging of bacterial chromosome
Gyrase
Several antiviral medications used to treat HIV interfere with
Nucleic acid synthesis
Bacterial DNA replication requires the enzyme gyrase, but eukaryotic replication does not. Ciprofloxacin (Cipro) inhibits gyrase activity. This is an example of
Selective toxicity
An antimicrobial that inhibits cell wall synthesis will result in which of the following
Cells become more susceptible to osmotic pressure
Infection of the ______ would be the hardest to treat with antimicrobial drugs
Brain
Mutagens are useful in biotechnology research for
Producing organisms with altered phenotypes
Probes used for detecting genetic sequences are frequently composed of
Synthetic nucleic acids and labeled conjugates, such as fluorescent dyes
Which of the following statements is CORRECT about bacterial transcription
Various stigma factors recognize different promoter sequences
What factors need to be considered when choosing a method of microbial control
The site and environment to be treated , and the susceptibility of the microbes
Although glycolysis requires an input of ATP, this pathway results in a net gain of two ATP; therefore, it is________ pathway.
An exergonic
The cooperative activity of drugs such as beta-lactam antibiotics and clavulanic acid, a B-lactamase inhibitor, is known as
Synergism
Which of the following statements is CORRECT about BOTH bacterial and eukaryotic DNA replication
Replication proceeds bidirectionally from the origin of replication
In the compound lamivudine an -SH group replaces an -OH group found in cytosine. When used as a medication it will
Interfere with nucleic acid synthesis
Inhibitors of DNA synthesis specifically effective on prokaryotes are
Quinolones
Hydrogen peroxide is NOT an effective antiseptic because
The catalase present in skin cells degrade it
A compound is extracted from a microbial culture and is modified in the laboratory for use as an oral medication. This product would be
Semisynthetic antimicrobial
The procedure known as "replica plating" is used in
Negative selection only
Changes in temperature or pH can cause enzymes to lose activity. What is a common feature of these two effects
Temperature and pH both induce an enzyme to lose its precise three-dimensional shape
Who discovered the first antibiotic widely available to the general public
Domagk
Bacillus licheniformis secretes a compound that inhibits the growth of other Gram- positive bacteria
Antibiotic
Hydrolases are generally involved in _______ reactions
Catabolic
The process of _______ produces amino acids from precurser metabolites and ammonia
Amination
In gel electrophoresis, DNA molecules move toward the ______ electrodes because they have an overall _______ charge
Positive, negative
Which of the following is the most appropriate pairing of microbe and biosafety level
Methicillin-resistant Staphylococcus aureus (MRSA), BSL-2
The process of ______ is best described as semiconservative
DNA replication
Beta-lactam antibiotics have an effect on which of the following types of cells
Bacterial cells
A microarray is assembled using
Single stranded DNA and silicon chips
If you started with a single DNA molecule, how many would you have at the end of six PCR cycles
64
The horizontal transfer process known as transduction
Involves a virus
Which of the following types of plasmids facilitates the transfer of genetic material among bacteria
Fertility plasmids
Which of the following occurs in DNA but Not RNA
Both deoxyribose and thymine
A stationary broth culture contains 10 billion cells. The microbial death rate during autoclaving of this spent culture is 1.5 minutes. How long must it be autoclaved to be considered sterile
16.5 minutes
Which of the following procedures would be used to introduce DNA into a single mouse cell
Microinjection
Which of the following is a primary advantage of semisynthetic drugs
They have a broader spectrum of action
Which of the following is a sterilizing agent
Peracetic acid
Semiconservative DNA replication means that
Each daughter DNA molecule is composed of one original strand and one new strand
The Ames test determines that a chemical is
Mutagenic in salmonella
Which of the following could be used to reduce production of harmful proteins in diseased animals
Antisense RNAs
DNA replication and RNA transcription have many features in common. Which of the following does not occur in both processes
A requirement for a primer
Which of the following are considered to be frameshift mutations
Both deletions and insertions
Gamma irradiation is a process for
Sterilization
Inducible operans
Are generally anabolic pathways
Ribozymes are required for
Both translation and RNA splicing
An antimicrobial agent that ______ will have the most lasting germicidal effect
Damages DNA
Physical removal of microbes without killing them is
Degerming
The metabolic processes called fermentation
Use an organic molecule as a final electron acceptor
________ may be achieved using chlorine dioxide
Disinfection
Which of the following causes mutations by creating thymine dimers
Ultraviolet light
The procedure used to identify individuals by their unique genetic sequences is known as
DNA fingerprinting
Which of the following is measured in the broth dilution test
Lack of turbidity
An effective tool for screening a large number of genetic sequences at once is known as
Microarray
Which of the following restriction enzyme site would produce blunt-ended fragments
CCC|GGG
A researcher finds a mutant mouse with a phenotype that may have applications to human disease. What would be the most efficient means of identifying the mutated gene
Use DNA fingerprinting to identify an altered DNA fragment, sequence it and search a gene library
The DNA double helix can be seperated into single strands using
Either heat or NaOH
Gluteraldehyde acts on microbes by
Forming chemical cross links in DNA and proteins
A wild-type organism and a genetic variant both have a gene encoding a receptor producing a chemotactic response to metabolite A. The genetic variant has a mutation in a regulatory gene for expression of the receptor. Which of the following statements with respect to the receptor is CORRECT
The organisms have the same receptor genotype but different phenotypes
Chemical reactions that are reversible, proceeding anabolically or catabolically, are called
Amphibolic
Which of the following pathways is specifically inhibited by trimethoprim
The conversion of dihydrofolic acid to tetrahydrofolic acid
A northern blot differs from a southern blot in the
Type of nucleic acid being isolated
Which of the following procedures is currently the standard test used in the United States for evaluating the efficiency of antiseptics and disinfectants
Use-dilution test
Typically eukaryotic genomes are composed of _______ DNA molecules
Multiple linear
Drug resistant populations of microbes arise when
Exposure to drugs selectively kills sensitive cells, allowing overgrowth of resistant cells
Which of the following processes is involved in the "central dogma" of genetics
Transcription and translation
The individual serving of half & half used in restaurants is usually treated by
Ultra- high temperature sterilization
The CDC issued alerts about a bacterial strain known as NDM1(New Delhi metals-lactamase 1). What type of antibiotic resistance is indicated by the name
Inactivation of the drug
Disinfecting agents naturally produced by microorganisms are
Antimicrobials
Boiling water for 10 minutes is effective in ridding it of
Both growing bacteria and enveloped viruses
DNA damage caused by ethidium bromide results in _______ mutations
Both insertion and deletion
A library of cloned sequences representing the expressed genes of an organism is known as a
cDNA library
A compound is structurally similar to PABA and inhibits folic acid synthesis. It is most likely a
Sulfonamide
Which of the following is a characteristic shared by DNA and RNA polymerases
Direction of polymerization
Antimicrobial sugar analogs are effective for
Preventing virus attachment
Which of the following statements is True of bacterial plasmids
They are small circular DNA molecules that can replicate autonomously
Which of the following can result when antibiotic therapy disrupts the normal microbiota
Both pseudomembranous colitis and thrush
In aerobic non-photosynthetic organisms, the majority of ATP is generated by
Oxidation-reduction reactions
The use of lysozyme during the preparation of cheeses and wines is effective in reducing the numbers of
Bacteria
Antimicrobial agents that damage nucleic acids also affect
Protein synthesis
A sulfonamide and trimethoprim may be administered in combination to
Reduce development of antibiotic resistance
The heavy metal compound _____ is used as a preservative in some vaccines
Thimerosal
Which of the following regulatory RNAs alter translation in response to environmental conditions
Riboswitches
The first synthetic antimicrobial widely available for treatment of infections
Was an antimetabolite
The B-lactams are narrow spectrum antibacterials because
The outer membrane prevents their entry into cells
Replacing the defective gene responsible for sickle-cell anemia is an example of
Gene therapy
A researcher has discovered a new metabolic product of a fungus that may have antimicrobial properties. Which method would be best for preparing the material for tests of its effect on bacteria
Filtration
Air can be disinfected using
Both HEPA filters and ultraviolet light
A medication which specifically targets cell walls that contain arabinogalactan-mycolic acid is
Isoniazid
Which of the following is bacteriostatic
Freezing below 0 degree Celsius
Filtration is a _____ method of achieving sterilization
Degerming
Examples of recent accomplishments in the use of recombinant DNA technology include
Gene therapy to correct an immune system deficiency in humans
The antimicrobial polymyxin is primarily effective for treating superficial infections with
Gram-negative bacteria
The process of _______ requires the activity of DNA ligase
DNA replication
Many metabolites for anabolic pathways are produced by the ________ pathway
Pentose-phosphate
Most drugs that inhibit the synthesis of the cell wall act by
Preventing the cross-linkage of NAM subunits
Which of the following is characteristic of prokaryotic genomes but NOT eukaryotic genomes
Circular chromosomes
The therapeutic range of an antimicrobial is the
Range of concentrations at which the antimicrobial is both effective and non-toxic
The mechanism of action of erythromycin is
Inhibition of protein synthesis
Disinfectants that damage membranes include
Both alcohols and phenolics
The phenolic________ is present in many consumers products labeled "antibacterial "
Triclosan
Silvadene, a topical treatment for burns, contains 1% silver. What category of chemical control agent is in Silvadene
Heavy metals
The process known as ______ is initiated with the incorporation of fMet
Translation
Ribavirin is an antiviral that interferes with
Nucleic acid synthesis
Synthesis of cDNA requires the use of
Reverse transcriptase
Which of the following is essential in PCR
Both DNA primers and DNA polymerase
Synthetic nucleic acids are produced using
Computerized assembly using replication enzymes in vitro
Which of the following best describes flash pasteurization
Heating at 72 degrees Celsius for 15 seconds
The process of incineration is used for
Sterilization
During the synthesis of acetyl-CoA from pyruvic acid, ______ is produced
NADH
Sigma factors are involved in the regulation of bacterial
Transcription
The detection of DNA by FISH makes use of
Synthetic DNAs and fluorescent tags
Specific DNA fragments can be isolated from a mixture of fragments using
An electrophoresis chamber
An instrument that will come into contact with only the skin of a patient should be disinfected with a
Low-level germicide
Which of the following products of glucose catabolism is a substrate for fatty acid synthesis
Acetyl-Coa
A researcher inserted DNA fragments from an organism into plasmids and introduced the modified plasmids into bacterial cells. Which of the following methods would be the most efficient means of identifying which clones contain a specific gene of interest
Use a labeled synthetic probe complementary to the gene sequence