Review 3 - Medical Micro
In Griffith’s experiments with Streptococcus pneumoniae, rough non-encapsulated Streptococci were converted into smooth encapsulated Streptococci in the presence of the heat-killed smooth encapsulated Streptococci. What is the term that describes this process?
Transformation
Which of the following addition have been made to principles of the central dogma of biology?
RNA can be used to regulate gene function
Which of the following is not true of transposons?
Are always part of plasmids
The jumping of a gene from one location to another is done by __________.
Transposons
A bacteriophage transfers DNA of the previous host to the current host. This is an example of __________.
Generalized transduction
The development of a virulent, toxin-producing bacterial strains due to the presence of a temperate phage can occur in __________.
Specialized transduction
The transfer of DNA fragments from a dead cell to a live, competent recipient cell that results in a changed recipient cell is __________.
Transformation
Hfr transfer involves all of the following except __________.
Plasmid gene transfer
Which of the following is not true of conjugation?
Transfers genes for a polysaccharide capsule
Which of the following is not a type of bacterial DNA recombination?
Mitosis
Which cell can transfer the most DNA?
Hfr cell
Bacterial conjugation involves __________.
A donor cell with a plasmid that synthesizes a pilus
The process in which mutations are removed and the correct bases added is called __________.
Excision repair
A screening system called the _________ test is used for detecting chemicals with carcinogenic potential.
Ames
What type of mutation alters the base, but not the amino acid being coded for?
Silent
A frameshift is caused by __________ mutations?
Deletion and insertion
If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATE (stop)?
Nonsense
If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATE THE BAG RAT?
Missense
If the wild type DNA sequence reads THE CATE ATE THE BIG RAT, what type of mutation would change the sequences to THE CAT ATA ETH EBI GRA T?
Insertion
The most serious type of mutation is a __________.
Frameshift mutation
A mutation that changes a normal codon to a stop codon is called a __________.
Nonsense mutation
Repressible operons require that __________ bind to the repressor before it can bind to the operator.
The product
Gene regulation can involve a protein repressor that blocks __________ from initiating transcription.
RNA polymerase
The lactose repressor _________.
Is inactivated by binding lactose
Full induction of the lactose operon requires _________.
Lactose present without glucose
Synthesis of a repressible enzyme is inhibited by _________.
Corepressor and repressor binding to operator
Synthesis of an inducible enzyme requires _________.
Substrate bound to repressor
The gene of an operon that codes for a protein repressor is called the _________.
Regulator
Which is incorrect about inducible operons?
Have genes turned off by a buildup of end product
Split genes _________.
Use spliceosomes to excise introns and then join exons
A sequence of bases on a gene that does not code for protein is called a/an _________.
Intron
Which of the following is not associated with a prokaryotic ribosome?
Small unit provides the enzymes for making peptide bonds
Which of the following is incorrect about termination of codons?
Include AUG
The following pertain to ribosomes during protein synthesis except _________.
Contain codons within their rRNA molecules
If a codon for alanine is GCA, then the anticodon is _________.
CGU
Which of the following is incorrect about transfer RNA?
Initiator tRNA in bacteria carries tryptophan
RNA polymerase binds to the _________.
Promoter sequence
The nontranscribed region of DNA to which RNA polymerase binds to initiate _________.
Promoter
All of the following pertain to transcription except _________.
Occurs on a ribosome in the cytoplasm
RNA molecules differ from DNA molecules because on RNA _________.
All of the choices are correct
This molecule is synthesized as a copy of a gene of the DNA template strand _________.
Messenger RNA
The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called _________.
Transfer RNA
The three-base sequence on DNA that codes for an amino acid is called a(n) _________.
Codon
Groups of three consecutive bases along the DNA of a gene have the code for one _________.
Amino acid
A primer of _________ is needed at the origin of nucleotide addition.
RNA
Replication of DNA begins at a(n) _________.
Adenine-thymine rich area
A permanent, inheritable change in the genetic information is called a(n) _________.
Mutation
DNA Polymerase III _________.
Proofreads new DNA
DNA Polymerase I _________.
Removes primers
Helicase __________.
Unwinds DNA
Helicase _________.
Unwinds DNA
DNA gyrase _________.
Cleaves DNA
The site where the old DNA strands separate and new DNA strands will be synthesized is called the _________.
Replication fork
The enzyme that can proofreads replicating DNA, detects incorrect bases, excises them, and correctly replaces them is _________.
DNA polymerase
The enzyme that helps pack DNA into the cell by coiling the DNA into a tight bundle is _________.
DNA gyrase
DNA polymerase III _________.
Synthesizes new DNA only in the 5’ to 3’ direction
Semiconservative replication refers to _________.
An original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule
During replication, each parent DNA strand serves as a _________ for synthesis of new DNA strands.
Template
Structural genes code for _________.
Cellular proteins
The duplication of a cell’s DNA is called _________.
Replication
Base pairs in DNA are held together by _________ bonds.
Hydrogen
Each nucleotide is composed of _________.
One phosphate, one nitrogenous base, one sugar
All of the following pertain to nitrogenous bases except _________.
Guanine pairs with uracil
The antiparallel arrangement within DNA molecules refers to _________.
One helix strand that runs from the 5’ to 3’ direction and the other strand runs from the 3’ to 5’ direction
Which is incorrect about purines?
Only found in DNA, not in RNA
The DNA of microorganisms is made up of subunits are called _________.
Nucleotides
The expression genetic traits is the __________.
Phenotype
Each _________ is a specific segment of the DNA with the code for production of one functional product.
Gene
A nucleosome is a linear chromosome wound around the _________.
Histone
The _________ is all of the genetic material of a cell.
Genome
Which of the following is not true of an organism’s genotype?
Are the expressed traits governed by the genes
Eukaryotic chromosomes differ from prokaryotic chromosomes because only eukaryotes have _________.
All of the choices are correct
Among the microorganisms, various genomes can include _________.
All of the choices are correct
If you have the sequence of mRNA that is AUAUGC, then the DNA antisense strand is _________.
TATACG
The enzyme _________ adds three nucleotides of DNA in the _________ direction when DNA is being semi-conservatively replicated.
DNA polymerase III, 5’ --> 3’
When determining the sequence of nucleotides in an unknown sample of DNA, which method is used to sequence the DNA?
The Sanger Method
All of the following are correct about DNA fingerprinting, except _________.
It cannot be used on specimens older than five years
When DNA is heated to just below boiling (90oC – 95oC).
The two DNA strands separate completely
The polymerase chain reaction (PCR) has been used in all of the following fields, except _________.
None of the choices; it is useful for all these fields
All of the following are characteristics that make plasmids good cloning vectors, except _________.
The can accept a relatively large amount of foreign DNA
The Southern Blot technique detects _________.
Specific genetic marker sequence on genes
Which of the following methods determines which genes are actively transcribed in a cell under a variety of conditions?
Microarray analysis
Which technique will hopefully be used to identify and devise treatments for diseases based on the genetic profile of the disease?
Microarray analysis
Which of the following is less subject to degradation than is chromosomal DNA and is used as an evolutionary time clock?
mitochondrial DNA
Which of the following drugs is/are produced by genetic engineering and approved for human use?
All of the choices are correct
All of the following are desirable features in a microbial cloning host, except it _________.
Has a slow growth rate
This is often used in forensic science to distinguish one sequence of DNA from another by comparing the sequences of the strands at specific loci _________.
DNA fingerprinting
Both DNA sequencing and polymerase chain reactions require special _________ to initiate synthesis of a new DNA molecule.
Primers
When patient tissues are transfected with viruses carrying a needed, normal human gene, the techniques is called _________.
Gene therapy
Transgenic animals _________.
All of the choices are correct
Recombinant strains of this organism are released to colonize plant roots to produce an insecticide to destroy invading insects _________.
Pseudomonas fluorescens
The commercial product Frostban contains a genetically engineered strain of _________.
Pseudomonas syringae
Which of the following is a serious concern when performing PCR?
Introduction and amplification of contaminating DNA
Which step involves transformation?
Cloning host takes up plasmid
In order to ensure compatibility between the target DNA and the plasmid DNA _________.
Target DNA and plasmid treated with the same restriction endonuclease
The primers in PCR are _________.
Synthetic DNA oligonucleotides
Thermococcus litoralis and Thermus aquaticus are thermophilic bacteria that are _________.
Sources of heat stable DNA polymerases
The fluorescent in situ hybridization (FISH) probes are applied to intact cells and observed microscopically for the presence and location of _________.
Specific genetic marker sequence on genes
The Western Blot technique detects _________.
Proteins
The function of the didcoxy (dd) nucleotides that are used in the Sanger method of DNA sequencing is to _________.
Incorporate into newly replicated DNA strands and stop elongation
Which PCR step synthesizes complementary DNA strands?
Add DNA polymerase and nucleotides at 72oC
Which PCR step causes the denaturation of double-stranded DNA?
Heat target DNA to 94oC
DNA polymerases used in PCR _________.
Are labeled with fluorescent dyes
Amplification of DNA is accomplished by _________.
Polymerase chain reaction
Gene probes can be labeled for detection with _________.
All of the choices are correct
Sequences of DNA that are identical when read from the 5’ to 3’ direction on one strand and the 3’ to 5’ direction on the other strand are _________.
Palindromes
EcoRI and HindIII are _________.
Restriction endonucleases
Geneticists can make complimentary DNA copies of messenger, transfer, and ribosomal RNA by using _________.
Reverse transcriptases
DNA strands can be clipped crosswise at selected positions by using enzymes called _________.
Restriction endonucleases
A technique that separates a readable pattern of DNA fragments is _________.
Gel electrophoresis
Labeled, known, short stretches of DNA used to detect a specific sequence of nucleotides in a mixture are _________.
Gene probes
The deliberate removal of genetic material from one organism and combining it with the genetic material of another organism is a specific technique called _________.
Recombinant DNA
The various techniques by which scientists manipulate DNA in the lab are called _________.
Genetic engineering
The use of an organism’s biochemical processes to create a product is _________.
Biotechnology
Commercial products containing which types of chemicals are more effective at killing microorganisms?
Bacteriocidal
Using toilet bowl cleaner and nonionizing radiation to inanimate surfaces only removes or kills vegetative bacteria. The term that best describes this action is _________.
Disinfection
Which of these metals have antimicrobial properties associated with them?
Both A and B are correct
Which of the following types of agents targets protein conformation?
Alcohol
All of the following are correct about the autoclave, except _________.
It is effective for sterilizing powders, oils, and waxy substances
Which common hospital pathogen is able to grow abundantly in soap dishes?
Pseudomonas
Historically, which of the following was instilled into the eyes of newborn infants to prevent gonococcal infections?
Silver nitrate
All of the following are methods of disinfection or sterilization, except _________.
Lyophilization
All of the following are benefits of food irradiation, except _________.
It makes the food less nutritious
ll of the following are correct about food irradiation, except _________.
The World Health Organization does not endorse this process
Which of the following is officially accepted as a sterilant and high-level disinfectant?
Glutaraldehyde
Which of the following chemicals is a disinfectant for soft contact lenses?
Hydrogen peroxide
Which of the following is being used to replace hypochlorites in treating water because of the possibility of cancer-causing substances being produced?
Chloramines
Ethylene oxide is _________.
Sporicidal
All of the following are correct about detergents, except _________.
They are active in the presence of organic matter
The chemical agents that produce highly reactive hydroxyl-free radicals and also decomposes to O2 gas is _________.
Hydrogen peroxide
The sterilizing gas used in a special chamber is _________.
Ethylene oxide
All of the following are correct about iodophors, except _________.
This formulation allows a quick release of free iodine
Which is mismatched?
Merthiolate – silver
Alcohols _________.
All of the choices are correct
The compound that is an organic base containing chlorine and two phenolic rings and is used increasingly for hand scrubbing, neonatal washes, wound degerming, and prepping surgical skin sites is _________.
Chlorhexidine
Iodophors include _________.
Betadine
Which of the following is not used as an antiseptic?
Aqueous glutaraldehyde
All of the following pertain to hypochlorites except _________.
Found in iodophors
Which control method would not be a suitable choice for killing Mycobacteria in a capped culture tube?
Ultraviolet (germicidal) light
The easiest microbial forms to kill or inhibit are _________.
Vegetative bacteria and fungi
All of the following are phenols or phenolics, except _________.
Chloramines
HEPA filters are used to remove microbes from _________.
Air
Disinfection of beverages, such as apple juice, milk, and wine, is optimally achieved by _________.
Pasteurization
The shortest time required to kill all the microbes in a sample at a specified temperature is called the __________.
Thermal death time (TDT)
Dry heat _________.
Is less efficient than moist heat
Sterilization is achieved by _________.
Steam autoclave
Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is _________.
Degermation
The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is _________.
Antisepsis
Microbiological contaminants are best described as _________.
Unwanted microbes present on or in a substance
What does Vancomycin target?
Both A & B are correct choices
Which bacteria does Levaquin target?
All of the choices are correct
All of the following are correct about Tamiflu and Relenza except _________.
The prevent assembly and release of the virus
Which of the following describes the mechanism of action for AZT?
It is a thymine analog that interferes with DNA synthesis
Why has the United States and Europe banned the use of human drugs in animal feeds?
Because it contributes to the growing drug resistance problem
Which of the following antimicrobials is contraindicated for children due to permanent tooth discoloration?
Tetracycline
Which organ is responsible for metabolizing and detoxifying foreign chemicals in the blood, including drugs?
Liver
All of the following are correct about allergic reactions to drugs, except _________.
Allergic reactions generally will occur the first time a person takes the drug
All of the following could be reason why antimicrobic treatment fails except _________.
A disk diffusion test showing pathogen sensitivity to the antimicrobic
Which of the following will influence a physician’s decision to prescribe and antimicrobial?
All of the choices are correct
A “shotgun” approach to antimicrobial therapy involves _________.
Using a broad spectrum drug so that the chance of killing the pathogen is greater
Antimicrobics effective against only gram-positive bacteria would be termed _________.
Narrow-spectrum drugs
A ratio of the dose of the drug that is toxic to humans versus the minimum effective dose for that pathogen is assessed to predict the potential for toxic drug reactions. This is called the _________.
Therapeutic index (TI)
A clinical microbiologist makes serial dilutions of several antimicrobics in broth, and the incubates each drug dilution series with a standard amount of a patient’s isolated pathogen. What is this microbiologist setting up?
Minimum inhibitory concentration (MIC)
Drug susceptibility testing _________.
Determines the pathogen’s response to various antimicrobics
A superinfection results from _________.
Decrease in most normal flora with overgrowth of the unaffected species
Side effects that occur in patient tissues while they are on antimicrobic drugs include all the following, except _________.
Development of resistance to the drug
The multidrug resistant pumps in many bacterial cell membranes cause _________.
Prevention of drug entry into the cell
The cellular basis for bacterial resistance to antimicrobics include _________.
All of the choices are correct
Acyclovir is used to treat _________.
Shingles, chickenpox, and genital herpes
Antivirals that target reverse transcriptase would be used to treat _________.
HIV
An antiviral that is a guanin analog would have an antiviral mode of action that _________.
Blocks DNA replication
Which of the following is not a mode of action of an antiviral?
Bond to ergosterol in the cell membrane
There are fewer antifungal, antiprotozoan, and antihelminth drugs compared to antibacterial drugs because these organisms _________.
Are so similar to human cells that selective drug toxicity is difficult to achieve
Ketoconazole, fluconazole, clotrimazole, and miconazole are broad-spectrum azoles used to treat _________ infections.
Fungal
Mebendazole, niclosamide, and ivermectin are drugs used to treat _________ infections.
Helminthic
The drug used for several protozoan infections is _________.
Metronidazole
The most versatile and useful antifungal drug that is used to treat serious systemic fungal infections is _________.
Amphotericin B
The drug used against intestinal anaerobic bacteria, that can also alter normal flora causing antibiotic associated colitis is _________.
Clindamycin
The drug that can cause aplastic anemia, and is used to treat typhoid fever and brain abscesses is _________.
Clindamycin
Antimicrobics that are macrolides _________.
Include azithromycin, clarithromycin and erythromycin
Salvarsan was _________.
Used to treat syphilis
Substances that are naturally produced by certain microorganisms that can inhibit or destroy other microorganisms are called _________.
Antibiotics
Antibiotics are derived from all the following, except _________.
Staphylococcus
Drug-resistant population of microbes arise when _________.
Exposure to drugs selectively kills sensitive cells allowing overgrowth of resistant cells
Ribavirin is an antiviral that interferes with _________.
Nucleic acid synthesis
Antiviral medication can best be described as _________.
Extremely narrow spectrum antimicrobials
The mechanisms of action of erythromycin is _________.
Inhibition of protein synthesis
Pentamidine is an example of an antimicrobial that _________.
Binds to DNA
Several antiviral medications used to treat HIV interfere with _________.
Nucleic acid synthesis
The mechanism of action of the antibiotic vancomycin is _________.
Inhibition of cell wall synthesis
How does resistance to drugs spread in bacterial populations?
The formation of biofilms protects bacteria from the effects of drugs
The β-lactams are narrow spectrum antibacterials because _________.
The outer membrane prevents their entry into cells
Disruption of the normal microbiota can result in infections caused by which of the following microbes?
Candida albicans, Mycobacterium, and Clostridium difficile
Which of the following is measured in the broth dilution test?
Lack of turbidity
Infection of the _________ would be hardest to treat with antimicrobial drugs.
Brain
Antimicrobial sugar analogs are effective for _________.
Preventing virus attachment
The therapeutic range of an antimicrobial is the _________.
Range of concentrations at which the antimicrobial is both effective and non-toxic
The E-test determines which of the following?
Both susceptibility and MIC (minimum inhibitory concentration)
Bacterial DNA replication requires the enzyme gyrase, but eukaryotic replication does not. Ciprofloxacin (“Cipro”) inhibits gyrase activity. This is an example of _________.
Selective toxicity
Synthetic antimicrobials that block protein synthesis by binding to the mRNA are _________.
Antisense nucleic acids
Which of the following pathways is specifically inhibited by trimethoprim?
The conversion of dihydrofolic acid to tetrahydrofolic acid
A medication that inhibits synthesis of ergosterol would be effective in treating _________.
Fungal infections
Most drugs that inhibit the synthesis of the cell wall act by _________.
Preventing the cross-linkage of NAM subunits
The CDC issued alerts about a bacterial strain known as NDM1 (New Delhi metalo-lactamase 1). What type of antibiotic resistance is indicated by the name?
Inactivation of the drug
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
The first synthetic antimicrobial widely available for treatment of infections _________
Was an attachment antagonist
Which of the following is a primary advantage of semisynthetic drugs?
They have a broader spectrum of action
Beta-lactam antibiotics have an effect on which of the following types of cells?
Bacterial cells
An antimicrobial that inhibits cell wall synthesis will result in which of the following?
Cells become more susceptible to osmotic pressure
Which of the following antibiotics disrupts the cytoplasmic membrane function?
Amphotericin B