Microbiology Ch. 8,
According to the animation, which of the following makes mRNA from the information stored in a DNA template?
RNA polymerase
An enzyme that copies DNA to make a molecule of RNA is
RNA polymerase
What enzyme is necessary for prokaryotic and eukaryotic transcription?
RNA polymerase
Most RNA viruses carry which of the following enzymes?
RNA-dependent RNA polymerase
Which of these enzymes is necessary for the replication of a + strand RNA virus?
RNA-dependent RNA polymerase
Rickettsia rickettsii is transmitted by ____________, and Rickettsia prowazekii is transmitted by ____________.
Rocky Mountain Spotted fever; transmitted by ticks
Which finding is most surprising from Griffith's experiments?
S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains.
Agarose gel electrophoresis separates DNA in a sample based on...
Separates out DNA depending up its size
Which of the following is an application that uses PCR?
Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism
In mice, the LD50 for staphylococcal enterotoxin is 1350 ng/kg, and the LD50 for Shiga toxin is 250 ng/kg. Which of the following statements is true?
Shiga toxin is more lethal than staphylococcal enterotoxin.
Shigella sp is the etiological agent of ___________, and Haemophilus influenzae is the etiological agent of ____________.
Shigella sp. (sp.= species)- shigellosis (bacterial dysentary), Haemophilus influenzae- meningitis (this organism doesn't cause influenza!)
Organism A has 70 moles % G+C, and organism B has 40 moles % G+C. Which of the following can be concluded from these data?
The two organisms are unrelated.
A lytic virus has infected a patient. Which of the following would best describe what is happening inside the patient?
The virus is causing the death of the infected cells in the patient.
Which of these answers is true for trematodes?
They may have more than one intermediate host.
Which statement regarding cyanobacteria is true?
They produce oxygen from water as they carry out photosynthesis.
What is the function of the primers in PCR?
They provide a 3' end for the DNA polymerase.
Which is NOT true of the rickettsias?
They reproduce by fragmentation.
How are viruses different from cells?
They require a host in order to reproduce.
Which of the following statements about the members of the Kingdom Animalia is FALSE?
They undergo photosynthesis.
Which of the following statements about members of the Kingdom Plantae is FALSE?
They use organic carbon sources.
Which of the following is NOT a member of Domain Archaea?
Thiomargarita
State the different properties of DNA vs. RNA; specifically their nucleotides, number of strands, function, and sugars
RNA: single stranded, RNA that is being synthesized will have a uracil instead of a thymine, DNA: double stranded,
Recently, a new parasitic helminth was described in a 3-year-old boy. The only unusual part of his history was that he played in a shed frequented by raccoons. To diagnose the child's behavioral changes and loss of speech and motor skills, doctors did MRIs and CT scans. The data collected from these scans suggested the presence of larval helminths in his brain. Which of the following is the most likely scenario?
Raccoons are the definitive hosts, and humans are accidental intermediate hosts.
An envelope is acquired during which of the following steps?
Release
During the Southern blotting technique, what is the purpose of transferring the DNA fragments from the gel to a nitrocellulose filter?
This step attaches the DNA fragments to a permanent substrate, which then can be probed
How many questions are needed in this dichotomous key to determine if the unknown is Bacteroides?
Three
What is the function of the structural elements of a virus?
To package and protect the viral genome
What is the end goal of PCR?
To quickly increase the number of copies of a specific DNA sequence
Which of the following is an example of horizontal gene transfer in bacteria?
Transduction, conjugation, and transformation
What is the hallmark of all horizontal gene transfers?
Transfer of DNA between organisms of the same generation
Which of the following bacteria is gram-negative?
Treponema
What species of protozoa causes the STD, Trichomoniasis?
Trichomonas vaginalis
Which of the following amino acids is coded by only one codon?
Trp
How many answers are there to a question in a dichotomous key flowchart?
Two
What are the products of semiconservative replication for a double-stranded DNA molecule?
Two double-stranded DNA molecules, each consisting of one parental strand and one daughter strand
What is the defining characteristic of organisms belonging to the phylum Parabasalid?
Undulating membrane; no cyst stage
Which of the following toxins and descriptions do NOT match?
Vibrio enterotoxin: a superantigen that destroys epithelial cells
Which statement regarding viral species is true?
Viral species are not classified as part of any of the three domains.
Which of the following is true of viroids?
Viroids are short pieces of naked RNA
How do all viruses differ from bacteria?
Viruses are not composed of cells.
Which of the following statements is a reason for NOT classifying viruses in one of the three domains of life (Bacteria, Archaea, Eukarya) rather than in a fourth separate domain?
Viruses are not composed of cells.
Which of the following best defines a strain in microbiological terms?
a pure culture that is not totally identical to other cultures of the same species
What contributes to antigenic shift in influenza viruses?
a segmented genome
A gene is best defined as
a sequence of nucleotides in DNA that codes for a functional product.
Which of the following is a reservoir of infection?
a sick person a sick animal a hospital a healthy person
Phage typing is based on the fact that
bacterial viruses attack only members of a specific species.
Which type of organism would NOT be included in the Domain Eukarya?
bacterium
If DNA ligase were NOT used in the creation of a recombinant plasmid, __________.
base-pairing would occur but the sugar phosphate backbone would not be connected
Why doesn't Taq polymerase denature with the high temperatures used in PCR?
because it is thermophilic and can withstand high temperatures
The main method of identifying unknown bacteria identification is ___________.
biochemical tests
Which of the following is NOT used as a criterion to classify viruses?
biochemical tests
Arsenic is a relatively common hazardous waste generated by smelting processes and can contaminate soil and water surrounding smelting facilities. A bioprocess using naturally occurring bacteria to remove arsenic has been developed. This process is an example of __________.
bioremediation
In a healthy human, resident microorganisms would be found in all of the following areas EXCEPT the __________.
bloodstream
Botulism is caused by ingestion of a proteinaceous exotoxin; therefore, it can easily be prevented by
boiling food prior to consumption.
In which of the following patterns of disease does the patient experience no signs or symptoms?
both incubation and convalescence
Which of the following diseases is NOT spread by droplet infection?
botulism
Competent cells are cells that
can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination.
Seventeen patients in ten hospitals had cutaneous infections caused by Rhizopus. In all seventeen patients, Elastoplast bandages were placed over sterile gauze pads to cover wounds. Fourteen of the patients had surgical wounds, two had venous line insertion sites, and one had a bite wound. Lesions present when the bandages were removed ranged from vesiculopustular eruptions to ulcerations and skin necrosis requiring debridement. Fungi are more likely than bacteria to contaminate bandages because they
can tolerate low-moisture conditions.
The most conclusive evidence that viruses cause cancers is provided by
cancer following injection of cell-free filtrates
A biochemical test, in the microbiology world, is used to determine
capability of a microbe to perform a specific enzymatic activity.
Robert Koch's studies on Bacillus anthracis established a sequence of experimental steps to prove that microbes __________.
cause disease
If two organisms have similar rRNA sequences, you can conclude that they
evolved from a common ancestor.
Which of these disease stages is most likely to be altered in length if the number of infecting organisms at the start of the infection is very high?
incubation period
An infection transmitted by a handkerchief or tissue is transmitted by __________.
indirect contact
A needlestick is an example of
indirect contact transmission by fomite.
Which of the following mechanisms is used by gram-negative bacteria to cross the blood-brain barrier?
inducing TNF
Burkholderia was reclassified from the gammaproteobacteria to the betaproteobacteria because
its rRNA sequence is similar to that of Neisseria.
Which of the following is NOT a step in translation?
joining of the Okazaki fragments
Mycoplasmas differ from other bacteria in that they
lack a cell wall
Actinomycetes differ from fungi in that actinomycetes
lack a membrane-bounded nucleus.
Which of the following is NOT an example of microbial antagonism (also known as competitive exclusion)?
microbes producing vitamins and growth factors that can be utilized by the host
The major significance of Robert Koch's work is that
microorganisms cause disease.
An ampicillin-sensitive culture of E. coli is transformed with a plasmid that contains the gene of interest plus an ampicillin-resistant gene. If it is then plated on an ampicillin-containing growth medium, ________
only the bacteria with the plasmid will grow
Assume you have isolated a multicellular heterotrophic organism that produces coenocytic hyphae, motile zoospores, and cellulose cell walls. It is most likely a(n)
oomycote alga.
Nucleic acid hybridization is based on the fact that
pairing between complementary bases occurs
Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides were removed,
polypeptide B would not be able to enter the cells.
Viruses are surrounded by a protein capsid which is composed of individual units called ____________.
possess various geometrical shapes called polyhedral structures
Borrelia is classified as a spirochete because it
possesses an axial filament.
A virus's ability to infect an animal cell depends primarily upon the
presence of receptor sites on the cell membrane.
When the antibiotic chloramphenicol binds to the 50S portion of the ribosome, the effect is to __________.
prevent the ribosome from moving along the mRNA strand
An infectious protein is a
prion.
Ingesting lactic acid bacteria to prevent colonization by intestinal pathogens such as Salmonella enterica during antibiotic therapy is an example of __________.
probiotics
Some actinomycetes are similar to filamentous fungi because they __________.
produce asexual reproductive spores
In the blue-white screening procedure, bacteria that are transformed with recombinant plasmid and cultured in media containing ampicillin and X-gal will __________.
produce white colonies
Which of the following is NOT an advantage of obtaining the protein product called human growth hormone by recombinant DNA technology rather than extraction from cadavers?
production of endotoxins
Mad cow disease is caused by a prion, which is an infectious __________.
protein
Which test involves placing samples of an unknown bacterium in saline, adding different antisera, and checking for clumping?
slide agglutination
The following steps occur during multiplication of retroviruses. Which is the fourth step?
synthesis of double-stranded DNA
Which of the following would be the first step in biosynthesis of a virus with a - (minus) strand of RNA?
synthesis of double-stranded RNA from an RNA template
Both transcription and DNA replication involve __________.
synthesis using a DNA template
Infections in which the pathogen is distributed throughout the body are referred to as generalized infections or __________.
systemic infections
What type of RNA possesses an anticodon?
tRNA
Which of the following is involved in bringing amino acids to the ribosomes?
tRNA
Which of the following is NOT a communicable disease?
tetanus
Which of these diseases does not have a human reservoir?
tetanus
In the lac operon of E. coli, __________.
the repressor protein binds to the operator in the absence of lactose
For the amino acid aspartic acid (asp), __________.
the sequence of the DNA template would be CTG
One of the most popular taxonomic tools is DNA fingerprinting to develop profiles of organisms. These profiles provide direct information about
the similarities between nucleotide sequences.
Which of the following statements correctly differentiates a genomic library from a cDNA library?
A genomic library contains fragments of the entire DNA in an organism's genome. A cDNA library contains the coding sequences of eukaryotic genes (minus the introns).
Which of these events is an example of contact transmission?
A person drinks from a cup used by another individual.
What results from the process of translation?
A polypeptide
What would happen if the mRNA codon that coded for Cys was mutated in the third position from a U to an A?
A stop codon would be introduced prematurely.
Which of the following would be an example of disease transmission via indirect contact?
A student sneezes on her test booklet. The instructor grades it and catches her cold
Which of these statements is true about transduction?
A virus is required for transfer of genetic material.
A newly identified bacterial pathogen has been shown to cause disease in humans, disrupting the production of some proteins by interfering with the function of the endoplasmic reticulum of liver cells. Under specific growth conditions, this bacterial strain secretes a protein that appears to be responsible for the pathology of the disease. This protein is composed of two polypeptide chains, one of which binds to a receptor on the surface of liver cells, stimulating the uptake of the protein by endocytosis. Once inside the cell, the other polypeptide component interferes with the activity of ribosomes bound to the endoplasmic reticulum. This bacterial protein will most likely be classified as a/an __________.
A-B toxin
Acanthamoeba keratitis (AK) is caused by the protozoan ___________.
Acanthamoeba polyphaga
Trypanosoma brucei causes ____________ and T. cruzi causes ___________.
African trypanosomiasis ("sleeping sickness") Chagas' disease
Genetic change in bacteria can be brought about by
All of the answers are correct.
Which of the following are possible strategies for treating viral infections?
All of the listed strategies are correct.
Which of the following statements concerning transcription is true?
All types of RNA in the cell are synthesized by transcription, which uses a portion of DNA as a template for copying.
thick-walled spore formed as a segment within a hypha?
Chlamydoconidium
_________ fission literally means "to divide in half", so the process produces two identical daughter cells that are approximately half the size of the original cell.
Binary fission
All of the following can form filaments EXCEPT __________.
Borrelia
Which type of transposon would contain a gene for transposase?
Both simple and complex transposons
Which of the following properties are true of both bacteria and viruses?
Both use a molecule of nucleic acid to determine heredity.
Which of the following is NOT an enteric?
Campylobacter
Yeast infections are caused by
Candida albicans.
The pathogenicity of which of the following is NOT the result of lysogeny?
Clostridium tetani
Clostridium botulinum is the etiological agent of ___________, and Bacillus anthracis is the etiological agent of ____________.
-Clostridium botulinum- botulism -Bacillus anthracis- anthrax
fragment
. A piece of DNA that represents only a portion of the entire chromosome
How do complex transposons differ from simple transposons?
Complex transposons code for additional genetic elements, such as antibiotic resistance genes; simple transposons only code for the transposase gene essential for the tranposon itself.
Bacterial conjugation is often referred to as bacterial sex. Why is this term inaccurate?
Conjugation does not result in the formation of new offspring.
Which statement about conjugation is false?
Conjugation is a process of bacterial reproduction
Which of these statements is NOT true for bacterial capsules?
Immune system antibodies are not produced against a capsule.
Which of the following events does NOT occur in diseases transmitted by vectors?
In biological transmission, the vector multiplies in the human host.
chromosomes
In eukaryotic organisms, the double-stranded helix of DNA and its associated proteins are packaged into linear structures
Which of the following describes how 5-bromouracil might create a mutation?
It can replace the base thymine, and can base pair with guanine rather than adenine.
Why is DNA polymerase from Thermus aquaticus ideal for PCR?
It can withstand the high temperatures associated with PCR.
Why is the unknown in this example not Pseudomonas?
It ferments lactose
Trichomonas vaginalis can be distinguished from other parasitic protozoa by which of the characteristics listed below?
It has an undulating membrane, infects the vagina, and is frequently transmitted by sexual contact.
Which of the following statements about the causative agent of Rocky Mountain spotted fever is FALSE?
It is found in soil and water
What is the function of the parental DNA in replication?
It serves as the template for DNA replication.
How would the results be different if this organism was Salmonella?
It would produce hydrogen sulfide.
Which of the following is an advantage of using E. coli to make a human gene product?
Its genes are well known.
An example of descriptive epidemiology is __________.
John Snow's study of the London cholera outbreak from 1848 to 1849
Which of the following is NOT true of the polymerase chain reaction (PCR)?
Large amounts of DNA must be isolated from the source organism.
Which member of the gammaproteobacteria is a potential cause of pneumonia and can be found in warm-water supply lines and air conditioning cooling towers?
Legionella
Which of these statements is true for restriction enzymes?
Restriction enzymes are useful in genetic engineering when they make staggered cuts in DNA.
The virus family ___________________ has RNA as its nucleic acid AND uses reverse transcriptase?
Retroviridae
You have isolated a gram-positive bacterium with low G + C content from unpasteurized milk. It infected a pregnant woman, and now you are worried that her child will be stillborn. What bacterium is it?
Listeria monocytogenes
Viruses that use RNA as a template for transcribing DNA include _________
Retroviridae
Rickettsia rickettsii is the etiological agent of ____________, and Rickettsia prowazekii is the etiological agent of ____________.
Rickettsia rickettsii -Rocky Mountain Spotted fever; transmitted by ticks -Rickettsia prowazekii- endemic typhus; transmitted by lice
Which of the following might specifically be used as part of a reverse-genetics approach to studying a gene?
RNA interference
Which of the following are used to silence specific genes and hold promise for treating cancer or viral diseases, such as hepatitis B?
RNA interference (RNAi)
Campylobacter jejuni is the etiological agent of ___________, and Helicobacter pylori is the etiological agent of ____________.
-Campylobacter jejuni- food poisoning, -Helicobacter pylori- peptic ulcers; stomach cancer
Viruses possess genetic material comprised of DNA or __________.
RNA
In E. coli, Hfr cells _____
can pass main chromosome genes to a recipient cell
Which of the following is NOT involved in the production of sexual spores in fungi?
conjugation
Bacteria and Archaea are similar in which of the following?
considered prokaryotic cells`\
The study of genetic material taken directly from the environment is
metagenomics.
Cell lines derived from transformed (cancerous) cells are called __________.
: continuous cell lines
The only known host of a pork tapeworm is a/an __________.
: human
Based on the animation, what is transferred during bacterial conjugation?
A bacterial plasmid
Chlamydia trachomatis causes the sexually transmitted disease (STD) ____________
-Chlamydia trachomatis- sexually transmitted disease (STD). Nongonococcal urethritis.
What disease is caused by the viruses belonging to the viral family from question 1
Hepatitis B virus
Which of the following is NOT a membrane-disrupting toxin?
) A-B toxin
pores are asexual spores?
-Arthroconidium 5-Chlamydoconidium 6-Conidiospore 7-Sporangiospore 4-Blastoconidium
A recessive trait is only observed if
-Each trait has two factors, and the recessive trait is only seen when both copies are recessive.
Escherichia coli is the etiological agent of ___________, and Salmonella typhi is the etiological agent of ____________.
-Escherichia coli- food poisoning, UTIs -Salmonella typhi- typhoid fever
Gram positive bacteria are divided into two phyla depending upon G+C content. The phylum ___________ has low G+C content while the phylum _________ has a high G+C content.
-Firmicutes (Low G+C content) -Actinobacteria (High G+C content)
Klebsiella pneumoniae is the etiological agent of ___________, and Yersinia pestis is the etiological agent of ____________.
-Klebsiella pneumoniae- pneumonia -Yersinia pestis- plague (Black Death)
What gram-positive organism is associated with MRSA infections?
-MRSA- methicillin resistant Staphylococcus aureus
Mycobacterium tuberculosis is the etiological agent of ___________, and Corynebacterium diphtheriae is the etiological agent of ____________.
-Mycobacterium tuberculosis- tuberculosis -Corynebacterium diphtheriae- diphtheria
What beta-hemolytic bacteria causes strep throat, scarlet fever, and rheumatic fever?
-Streptococcus pyogenes-
Treponema pallidum is the etiological agent of __________, and Borellia burgdorferi is the etiological agent of __________.
-Treponema pallidum- syphilis -Borellia burgdorferi- Lyme disease
Typically bacteria possess
1 circular double-stranded chromosome that is supercoiled. The supercoiling allow the DNA to occupy a smaller area within the bacterial cell. The DNA double helix is composed of 2 complementary strands-these strands are composed nucleotides.
A dichotomous key _____________.
1) Is a series of paired statements, of which only one applies to the unknown in question. 2) Is a rapid and reliable method for identifying bacterial unknowns. 3) relies heavily on biochemical tests.
Which of the following places the steps in the PCR procedure in the correct order?
1, 3, 2
The chemical 5-bromouracil is a mutagen because it __________.
100%
A technician is staining organisms in a fecal sample collected from a boy complaining of abdominal cramping and diarrhea. The results show a protozoan that has eight flagella and two structures that give the organism the appearance of having large "eyes". The technician identifies the organism as Giardia intestinalis. What are the structures that resemble eyes in this organism?
2 nuclei
characteristic of Penicillium?
2-Ascospore 6-Conidiospore
According to the animation, ribosomes move along the mRNA in which direction?
5' to 3'
In which direction does DNA polymerase synthesize the new DNA strand?
5' to 3'
characteristic of Rhizopus?
7-Sporangiospore 8-Zygospore
You have a small gene that you wish replicated by PCR. After 3 replication cycles, how many double-stranded DNA molecules do you have?
8
Scientists like to use fluorescent proteins for various types of recombinant DNA procedures. You have a very small amount of the gene for a fluorescent protein. You'd like to make a fluorescent bacterium. Which of the following represents the correct sequence of procedures that you would use?
Amplify the gene using PCR. Insert the gene into a plasmid vector. Transform the vector into the bacteria
Which of the following would be an example of an infection initiated via the parenteral route?
An individual contracts hepatitis B from an accidental stick with a contaminated needle.
Why is DNA replication essential for a cell?
An organism must copy its DNA to pass genetic information to its offspring.
Into which group would you place a multicellular organism that has a mouth and lives inside the human liver?
Animalia
Which phylum of protozoa contains organisms that are non-motile, obligate intracellular parasites?
Apicomplexa
A new microorganism has been isolated from hot springs in Yellowstone National Park. It consists of single cells, which appear to lack a nucleus. Chemical analysis shows the presence of both DNA and RNA in the cytoplasm and pseudomurein in the cell wall. In which of the following groups will this organism be classified?
Archaea
Prokaryotic extremophiles are found in the domain __________.
Archaea-
You discovered a unicellular organism that lacks a nucleus and peptidoglycan. You suspect the organism is in the group
Archaea.
Which of these statements is NOT true?
Attachment of animal viruses to host cells is random and nonspecific.
Which of the following is an endospore-forming bacterium?
Bacillus
Using the more complex key on the previous slide, which organism would be described by the following characteristics: Gram positive bacilli Spore-former positive Mannitol positive Voges-Proskauer positive
Bacillus subtilis
Which of the following do you expect to be MOST resistant to high temperatures?
Bacillus subtilis
Into which group would you place a photosynthetic cell that lacks a nucleus?
Bacteria
Into which group would you place a unicellular organism that has 70S ribosomes and a peptidoglycan cell wall?
Bacteria
How is bacterial translation different from eukaryotic translation?
Bacteria can begin translation before transcription has terminated.
Why is visualization not sufficient to properly identify bacteria?
Bacteria have a limited set of shapes and many unrelated bacteria share the same shape.
Which of the following is characteristic of bacteria?
Bacteria lack a membrane-bound nucleus.
All living organisms can be classified into three domains: __________.
Bacteria, Archaea, and Eukarya
Which of the following might result in a frameshift mutation?
Benzopyrene
Using the same simple key starting with Step 2 the following characteristics have been observed: Cells are not spherical in shape Cells are not rod-shaped Cells are club-shaped Using these characteristics, which genus of organism do we have?
Corynebacteria
During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years.
Coxiella burnetii.
Which of the following is a human disease caused by prions?
Creutzfeldt-Jakob disease (CJD)
You see acid-fast oocysts in a fecal sample from a patient who has diarrhea. What is the MOST likely cause?
Cryptosporidium
Which answer is NOT true of bacterial photosynthesis and/or photosynthetic bacteria?
Cyanobacteria deposit sulfur derived from the splitting of hydrogen sulfide outside of the cells.
Which of the following are used by the Centers for Disease Control and Prevention to track outbreaks of foodborne disease?
DNA fingerprints, restriction fragment length polymorphisms, and reverse-transcriptase PCR(rtPCR)
An enzyme that makes covalent bonds between Okazaki fragments is
DNA ligase
In general, viruses contain either ________ or _________ as their nucleic acid.
DNA or RNA
Which of the following is most likely a product of an early gene?
DNA polymerase
Which of the following places these items in the correct order for DNA-virus replication?
DNA synthesis, Transcription, Translation, Maturation
Extrachromosomal DNA that can carry antibiotic resistance genes are called ______
R-factors
What provides the energy for DNA polymerization in a PCR reaction?
Deoxyribonucleoside triphosphates
What step in PCR "melts" double stranded DNA?
During the denaturing step,
Which of the following is an example of the symbiotic relationship known as mutualism?
E. coli within the large intestine
Which of these statements is NOT true of translation?
Each amino acid is coded for by a single codon.
Which of these events leads to all of the others in a pyrogenic (fever) response?
Endotoxin is released from the cell wall of gram-negative bacteria.
Which gammaproteobacteria are facultatively anaerobic, gram-negative rods that inhabit the intestinal tracts of humans and other animals?
Enterobacteriales
Which of these answers is true of the Apicomplexa?
Enzyme-containing organelles are present at one end.
Which of these bacteria is NOT associated with foodborne illness?
Erwinia
Which one of the following bacteria does NOT belong with the others?
Escherichia
Which of the following organisms is photoautotrophic protozoan?
Euglena
Which of the following is an INCORRECT match regarding motility?
Euglenozoa; nonmotile
A unicellular, photosynthetic nucleated cell would belong to which domain?
Eukarya
DNA called ktDNA is found in protozoans in genera Leishmania, and Trypanosoma. Where is ktDNA located?
Extranuclear DNA is defined as DNA found outside of the organism's nucleus. The designation for kinetoplast DNA is ktDNA.
Francisella tularensis is the etiological agent of ___________, and Legionella pneumophila is the etiological agent of ____________.
Francisella tularensis is the etiological agent of tularemia,
Into which group would you place a multicellular heterotroph with chitin cell walls?
Fungi
Gram positive bacteria are divided into two phyla depending upon G+C content. The letter "G" represents _________ and the letter "C" represents _________.
G+C content means the percentage of guanine and cytosinse nucleotides that are present in the bacterial DNA
Which of the following is a DNA strand complementary to CGA ATC AGC?
GCT TAG TCG
For the peptide with the amino acid sequence, proline-alanine-glycine (pro-ala-gly), the DNA template strand could have the sequence __________.
GGC CGA CCG
You have isolated a prokaryotic cell. The first step in identification is a(n)
Gram stain
The first question in this dichotomous key addresses
Gram stain differences
Requirements for X and V factors are used to identify
Haemophilus.
If a patient is diagnosed with a peptic ulcer, which genus of proteobacteria is probably responsible?
Helicobacter
Which of the following is an example of a helical bacterium that does NOT make a complete twist?
Helicobacter
A double-stranded, enveloped DNA virus that contains reverse transcriptase belongs to which family?
Hepadnaviridae
The virus family ___________________ has DNA as its nucleic acid AND uses reverse transcriptase.
Hepadnaviridae
Viruses that utilize reverse transcriptase belong to the virus families
Hepadnaviridae and Retroviridae.
Plasmodium falciparum causes the most deadly form of __________.
Malaria
What is the outstanding characteristic of the Kingdom Fungi?
Members absorb dissolved organic matter.
As shown in the animation, the start codon also codes for which amino acid?
Methionine
Why is microscopy not sufficient to identify microorganism?
Microscopy provides only visual clues, and many bacteria share the same visual characteristics.
Which of the following statements is NOT true of base substitutions?
Mutations rarely involve base substitutions.
Capsules play a role in the virulence of all of the following EXCEPT __________.
Mycobacterium tuberculosis
Which of the following statements regarding protozoa is FALSE?
Nearly all protozoa cause disease.
Which of these bacteria is NOT in the phylum Actinobacteria?
Neisseria
Which of the following bacteria are INCORRECTLY matched with gram reaction and morphology?
Neisseria; gram-positive coccus
Which of the following bacteria does NOT fix nitrogen?
Nitrobacter
Which of the following statements concerning prion diseases is true?
Normal host cellular prion proteins (PrPC) are converted into scrapie proteins (PrPSc).
Germ-free (gnotobiotic) animals often are more susceptible to infections and serious disease than are animals with a typical complement of normal microbiota. Based on this observation, which of the following would be an appropriate conclusion?
Normal microbiota stimulate the development of the immune system.
Which of the following is the best evidence for a three-domain system?
Nucleotide sequences in ribosomal RNA vary between all three domains.
________ were first identified in cancer-causing viruses and can induce ________ in infected cells.
Oncogenes; transformation
Which of the following statements is NOT true for Pelagibacter?
Pelagibacter's photosynthetic capability makes it a key producer in marine ecosystems.
The definition of lysogeny is
Phage DNA is incorporated into host cell DNA
Which of the following organisms requires an additional non-human host to complete its life cycle?
Plasmodium species
Which of the following terms are NOT correctly matched?
Poxviridae; chickenpox
Which of the following is necessary for replication of a prion?
PrPSc
A bacterium isolated from the soil has the following characteristics: it is a gram-negative straight rod, it is aerobic and motile, it produces water-soluble pigment, and it readily grows on several common laboratory media. Ribosomal RNA analysis places this bacterium with the gammaproteobacteria. This organism is most likely in the genus __________.
Pseudomonas
Which of the following pairs is mismatched?
Pseudomonas gram-positive
Coxiella burnetti is the etiological agent of ___________, and Vibrio cholerae is the etiological agent of ____________.
Q fever, cholera
How many codons code for the amino acid arginine?
Six
Which statement concerning viral structure is true?
Spikes are found on some viruses. They are very consistent in structure and can be used for identification.
Which organism is NOT correctly matched to its motility?
Spirillum; axial filaments
Which of the following bacteria does NOT belong with the others?
Staphylococcus
The LD50 of Vibrio choleraeis 108 cells through the oral route. If the bacterial cells are ingested with bicarbonate, the LD50 drops to 104. Which of these explanations is the most likely?
Stomach acid decreases the virulence of Vibrio cholerae.
Which of the following bacteria is gram-positive?
Streptococcus
What mRNA sequence is synthesized using the DNA template strand AATCCGAGGT?
TTUGGCTCCU
Humans are the definitive host for __________, which is a type of __________.
Taenia saginata; tapeworm
Which of the following statements concerning viruses is true?
The "host range" for a virus is determined by the presence or absence of particular components on the surface of a host cell that are required for the virus to attach.
What most likely explains the recovery of live S strain cells from a mouse injected with heat-killed S strain mixed with live R strain cells?
The R strain picked up the S strain DNA, enabling it to produce a capsule.
What characteristic of the S strain allows it to evade the immune system of the mice?
The cells have a capsule
What must occur for bacterial conjugation to take place?
The cells must come into contact with each other.
How is fermentation of lactose detected?
The drop in pH turns the indicator dye yellow.
How do the strands separate during PCR?
The high heat of the denaturation step breaks the hydrogen bonds between the two strands.
What is a thermocycler?
The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR
What test result indicates that the unknown can utilize citrate as its sole carbon source?
The medium turns blue.
complementary base pairing
The nitrogenous base located on one strand will pair with one on the 2nd strand using hydrogen bonds. Complementary base pairs that occur between DNA strands are: adenine pairs with thymine (A-T or T-A); and guanine pairs with cytosine (G-C or C-G)
Which of the following is NOT necessary to satisfy Koch's postulates?
The organism must cause disease through toxin production.
Koch's postulates established criteria for proving that a specific organism causes a specific disease. Which of the following is NOT one of the criteria given by Koch's postulates?
The pathogen must be isolated from inoculated animals and must be different from the original organism.
Which of the following statements about the development of infectious diseases is correct?
The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state).
Which of these answers is NOT true for positive (direct) selection?
The procedure detects altered genotypes regardless of the phenotype.
What is the function of enzyme "reverse transcriptase"?
The retrovirus uses RT to make DNA from their RNA which is then inserted into its hosts genome. Once the viral DNA is incorporated into the host genome, the viral genes will be transcribed and translated using the host's machinery to synthesize the components needed to construct more virus particles within the cell. Scientists utilize the property of this enzyme to construct cDNA for research purposes.
Which codon sequence codes for the "start" codon and what amino acid does it code for?
The start codon always codes for methionine in eukaryotes and a modified Met (fMet) in prokaryotes.
Consider the polypeptide sequence encoded by the following DNA. TACAAAGAAATT If base number 6 is changed to G, how will this affect the polypeptide?
There will be no change in the polypeptide.
A source of heat-stable DNA polymerase is
Thermus aquaticus.
Why are flowcharts useful for dichotomous keys?
They allow the researcher to visualize relationships between different bacteria.
All of the following are characteristic of algae EXCEPT which ONE of the following?
They are currently classified as plants
Which statement is NOT true of endotoxins?
They are eliminated from the body as a result of antitoxin production.
Which of the following statements in NOT true of plasmids?
They are essential for survival of the organism in most situations.
Which of the following statements about viral spikes is FALSE?
They are found only on nonenveloped viruses
Which of the following statements provides the most significant support for the idea that viruses are nonliving chemicals?
They are not composed of cells.
Which of the following statements is NOT true of the genus Mycoplasma ?
They are obligate intracellular pathogens.
Which of the following statements is NOT true of A-B exotoxins?
They are produced only by gram-negative bacteria.
Which statement is true of endotoxins?
They are released upon cell lysis.
What is the hallmark of dichotomous keys?
They consist of a series of paired statements, in which only one statement of each pair applies to a given organism.
Which of the following is NOT a characteristic of members of the Domain Archaea?
They contain nuclei.
Which of the following statements is true of members of the order Lactobacillales?
They do not perform aerobic or anaerobic respiration.
Which of the following statements about archaea is FALSE?
They evolved before bacteria.
Which of the following statements about viruses is FALSE?
Viruses use their own catabolic enzymes.
Which of the following techniques could be used to identify antibodies produced by a patient?
Western blotting
Which of the following statements about protozoa is true?
When conditions become harsh, some protozoa can form a protective capsule, which is called a cyst
All of the following are prion diseases EXCEPT __
Wiles-Davidoff syndrome
The crab industry needs female crabs for growing more crabs. What bacterium might be used to ensure development of female crabs and shrimp?
Wolbachia
Why is baker's yeast useful for expressing genetically engineered genes?
Yeast cells are eukaryotic and so would likely be successful in expressing eukaryotic genes.
A fungus that produces sporangiospores and zygospores and has hyphae without cross-walls would be classified in the category __________.
Zygomycota
In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes
a decrease in blood pressure
To what does the term viral species refer?
a group of viruses sharing the same genetic information and structure
Which of the following is a fomite?
a hypodermic needle
A genus can best be defined as
a taxon composed of one or more species and a classification level lying below family.
The cell theory states that __________ are made up of cells.
all living things
A nosocomial infection is
acquired during the course of hospitalization.
Which of these eukaryotic molecules/structures can be responsible for movement of bacteria within host cells?
actin molecules
Which of the following is NOT a step in Southern blotting?
addition of heat-stable DNA polymerase
In the Southern blot technique, which of the following is NOT required?
addition of heat-stable DNA polymerase to amplify DNA
Which of these substances are most important in the establishment of biofilms?
adhesins
The fimbriae of Neisseria gonorrhea and enteropathogenic E. coli are examples of
adhesins and ligands.
A definitive host harbors which stage of a parasite?
adult
In Pasteur's swan-neck flask experiment, the importance of the S-shaped curves in the flasks was twofold. The curves allowed entry of air but excluded __________.
airborne bacteria
Dinoflagellates are a type of unicellular __________. One genus of dinoflagellates is responsible for a foodborne disease called __________.
algae; paralytic shellfish poisoning (PSP)
The full complement of genes that an organism possesses in its genome is its _____________.
alleles
The miRNAs in a cell
allow different cells to produce different proteins.
The process of making multiple copies of a DNA molecule is referred to as __________.
amplification
Which of the following pairs is mismatched?
anamorphs lack spores
What enzyme is needed to amplify the DNA target sequence?
anneal
Serological testing is based on the fact that
antibodies react specifically with an antigen.
Microbes are NOT responsible for __________.
antibody production
The ability of some microbes, such as Trypanosoma or Giardia to alter their surface molecules and evade destruction by the host's antibodies is called
antigenic variation
Symptoms of disease differ from signs of disease in that symptoms
are changes felt by the patient.
Fungal spores __________.
are considered "reproductive" spores
Lichens __________
are organisms made of a fungus and a photosynthetic partner
Transient microbiota differ from normal microbiota in that transient microbiota
are present for a relatively short time.
Genes
are stretches of DNA that code for these functional molecules. Many genes code for proteins and functional RNA products such as ribosomal RNA (rRNA) & transfer RNA (tRNA). Prokaryotic DNA and eukaryotic DNA share many of the same properties, but they structurally different.
Biochemical tests _________________.
are the main methods used to identify unknown bacteria
Transformation is the transfer of DNA from a donor to a recipient cell
as naked DNA in solution.
How are the questions in a dichotomous key phrased?
as yes/no statements, allowing for multiple characteristics to be applied to an unknown specimen
Which of the following is a nucleated, unicellular organism that, if you changed the incubation temperature, would form filaments with conidiospores?
ascomycete
GAU codes for
aspartic acid.
When two DNA pieces cut with the same restriction enzyme are combined, sticky ends will __________.
associate by complementary base pairing and hydrogen bonds
All of the following are eukaryotes EXCEPT __________.
bacteria
You have isolated an aerobic gram-positive, endospore-forming bacterium that grows well on nutrient agar. To which of the following groups does it most likely belong?
bacillales
The presence of bacteria in the bloodstream is referred to as __________.
bacteremia
Nagleria fowleri is a protozoan that causes primary amoebic meningoencephalitis (PAM). It is contracted from the introduction of contaminated water into the nasal passages while swimming in freshwater lakes and ponds. Because of the symptomology of PAM, N. fowleri is often referred to as the ________________?
brain-eating amoeba
The mechanism whereby an enveloped virus leaves a host cell is called
budding.
A sequence of RNA derived from eukaryotic transcription that must be spliced out to achieve a mature strand of mRNA is called...
cDNA
For the introduction of a genetically modified plasmid into E. coli, __________.
calcium chloride and heat shock can be used
A nucleotide-altering chemical
can alter nitrogenous bases of DNA, resulting in incorrect base pairing
Which of the following does NOT contribute to the symptoms of a fungal disease?
cell walls
Fungi are __________.
chemoheterotrophs
Which disease would be potentially propagated in an environment without functional plumbing and in which drinking water is contaminated with sewage?
cholera
Which one of these pairs is NOT correctly matched?
coagulase; lyses fibrin clots
An example of a latent viral infection is
cold sores.
Women who have a healthy population of Lactobacillus spp. as part of the normal vaginal microbiota are less likely to get yeast infections. Which of the following terms is used to explain this observation?
competitive exclusion
Continuous cell lines differ from primary cell lines in that
continuous cell lines can be maintained through an indefinite number of generations.
The life cycle of the fish tapeworm is similar to that of the beef tapeworm. Which of the following is the most effective preventive measure?
cooking fish before eating
Which virus is NOT associated with cancer?
coronavirus
An exposure to __________ protects against infection with smallpox.
cowpox
Recombinant DNA technology is used for all of the following EXCEPT ________.
culturing unknown organisms
The damage caused by ultraviolet radiation is
cut out and replaced.
The ID50 for cutaneous anthrax due to Bacillus anthracis is 10 to 50 endospores, while the ID50 for inhalation anthrax is 10,000 to 20,000 endospores. This means that __________.
cutaneous anthrax is easier to acquire than inhalation anthrax
The term dermatophyte is typically used for fungi that cause which of the following?
cutaneous mycoses
The encysted larva of the beef tapeworm is called a
cysticercus.
Superantigens produce intense immune responses by stimulating lymphocytes to produce
cytokines.
the table shows the ID50 for Staphylococcus aureus in wounds with and without the administration of ampicillin before surgery. Based on the data, the administration of ampicillin before surgery
decreases the risk of staphylococcal infection.
What does it mean when scientists state that there is a "degeneracy in the genetic code"?
degeneracy allows for a certain amount of misreading of, or mutation in, the DNA without affecting the protein ultimately produced
The symptoms of malaria are.... (list 5)
diarrhea, nausea, vomiting, fatigue and fever.
A unicellular alga with cell walls containing pectin and silica is isolated from coastal waters. It is capable of photosynthesis and stores oil for energy. This alga is most likely a __________.
diatom
The following steps occur during multiplication of herpesviruses. Which is the third step?
uncoating
In mid-December, a woman with insulin-dependent diabetes who had been on prednisone fell and received an abrasion on the dorsal side of her right hand. She was placed on penicillin. By the end of January, the ulcer had not healed, and she was referred to a plastic surgeon. On January 30, a swab of the wound was cultured at 35°C on blood agar. On the same day, a smear was made for Gram staining. The Gram stain showed large (10 µm) cells. Brownish, waxy colonies grew on the blood agar. Slide cultures set up on February 1 and incubated at 25°C showed septate hyphae and single conidia. The most likely cause of the infection is a
dimorphic fungus.
Saxitoxin is produced by __________.
dinoflagellates
epidemic level.
disease acquired by many people in a given area in a short time
You are an epidemiologist studying an emerging disease reported over the past three years in Wisconsin, Minnesota, and Michigan. You have noticed a seasonal pattern of disease, with new cases appearing in late April through September and peaking in July. No new cases appear during late fall or the winter months. This pattern is suggestive of __________.
disease transmission by an arthropod vector, such as a mosquito or tick
Which type of microscope is needed to view a virus in the laboratory?
electron
Which of the following is the most effective control for malaria?
eliminate Anopheles mosquitoes
Increased human exposure to new and unusual infectious agents in areas that are undergoing ecologic changes accounts for the __________.
emergence of new infectious diseases
Malaria is an infectious disease caused by infection with a protozoan. In certain tropical regions, malaria is constantly present. We would say that malaria is a(n) __________ disease in these regions.
endemic
Which structure is NOT found in cestodes?
endospores
Patients developed inflammation a few hours following eye surgery. Instruments and solutions were sterile, and the Limulus assay was positive. The patients' inflammation was due to
endotoxin.
The science that deals with when diseases occur and how they are transmitted is called
epidemiology.
Which of the following are found primarily in the intestines of humans?
facultatively anaerobic gram-negative rods
Which type of bacterial enzyme helps spread Streptococcus pyogenes by digesting blood clots?
fibrinolysin
What cell structures does Neisseria gonorrhoeae use to attach and enter host epithelial cells?
fimbriae
Some members of the genus Rhizobium are notable for their ability to __________.
form nodules in plant roots that allow nitrogen fixation
Deleting or inserting one nucleotide pair in the middle of a gene is an example of which of the following?
frameshift mutation
A base insertion or deletion in the translated region of the gene may lead to
frameshift mutation.
A new soil microorganism has been described. On some growth media, it forms colonies of unicellular organisms, but under certain conditions it forms long, multicellular filaments and spores. The cells have nuclei, and their cell walls are composed of chitin. To which of the following groups does this new organism belong?
fungi
Ringworm is caused by a(n)
fungus.
Helminthic diseases are usually transmitted to humans by
gastrointestinal route.
A clone is
genetically identical cells derived from a single cell.
The random shotgun method is used in
genome sequencing
Which one of the following does NOT contribute to the incidence of nosocomial infections?
gram-negative cell walls
Salmonella, Shigella, Yersinia, and Serratia are all
gram-negative facultatively anaerobic rods.
Which of the following groups of algae does NOT produce compounds that are toxic to humans?
green algae
Staphylococcus and Streptococcus can be easily differentiated in a laboratory by which one of the following?
growth in high salt concentrations
A viral species is a group of viruses that
has the same genetic information and ecological niche.
All of the following are characteristic of the Platyhelminthes EXCEPT that they
have highly developed digestive and nervous systems.
One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in
increased susceptibility to disease.
Which of the following enzymes unwinds the two strands of DNA so that they can be copied during replication?
helicase
Which of the following contains an INCORRECT match?
hookworm; incomplete digestive system
Which of the following arthropods does NOT transmit diseases by sucking blood from a human host?
houseflies
The necessary ingredients for DNA synthesis can be mixed together in a test tube. The DNA polymerase is from Thermus aquaticus, and the template is from a human cell. The DNA synthesized would be most similar to
human DNA.
Three weeks after a river rafting trip, three family members experienced symptoms of coughing, fever, and chest pain. During the rafting trip, the family had consumed crayfish that they caught along the river banks. An examination of the patients' sputum revealed helminth eggs, and serum samples were positive for antibodies to Paragonimus. All of the family members recovered following treatment with praziquantel. In the Paragonimus life cycle,
humans are the definitive host and crayfish are the intermediate host.
Most polyhedral viruses have 20 triangular-shaped sides and are called ____________.
icosahedral
Mutagens
increase the likelihood of mutations in DNA.
Four days after playing in the wading pool at a neighborhood park, several 3- and 4-year-old children experienced abdominal cramping and watery diarrhea. Upon microscopically examining the children's stools with an acid-fast stain, doctors found red, cyst-like structures about 10 microns in diameter. What is the most likely diagnosis?
infection with Cryptosporidium spp.
A viroid is a(n)
infectious piece of RNA without a capsid.
Bacteriophage replication differs from animal virus replication because only bacteriophage replication involves
injection of naked nucleic acid into the host cell.
For Agrobacterium tumefaciens to be used to introduce foreign DNA into a plant cell, that DNA must first be __________.
inserted into the T-DNA region of the Ti plasmid of A. tumefaciens
If you have inserted a gene in the Ti plasmid, the next step in genetic engineering is
inserting the Ti plasmid into Agrobacterium.
If a larva of Echinococcus granulosus is found in humans, humans are the
intermediate host.
In the malaria parasite life cycle, humans are the ________ host, while mosquitoes are the ________ host as well as the vector.
intermediate; definitive
What do tapeworms eat?
intestinal contents
Enteric bacteria would most likely be found in which environment?
intestinal tract of an animal
Siderophores are bacterial proteins that compete with the host's
iron-transport proteins.
A recombinant cell
is a cell that receives DNA from an outside source and incorporates it into its own.
DNA
is a double-stranded, organic molecule that contains the "instructions" to produce the molecules that make-up organism and allow it to function.
Which of the following applications of recombinant DNA technology is NOT controversial?
metagenomics
Giardia and Trichomonas are unusual eukaryotes because they
lack mitochondria.
An advantage of cDNA over genomic DNA is that it
lacks introns
Some viruses, such as human herpesvirus 1, infect a cell without causing symptoms. These are called
latent viruses.
A disease in which the causative agent remains inactive for a time before producing symptoms is referred to as
latent.
Focal infections initially start out as
local infections.
Which of these viral cytopathic effects is most likely to be associated with the development of cancer?
loss of contact inhibition
Which of the following can be translated into protein?
mRNA
The reaction catalyzed by reverse transcriptase is
mRNA → cDNA
Transcription produces which of the following?
mRNA, tRNA, and rRNA are all produced by transcription.
Ehrlich searched for a/an __________ that would destroy a pathogen without harming the infected host.
magic bullet
A commensal bacterium
may also be an opportunistic pathogen.
All of the following are methods of avoiding host antibodies EXCEPT
membrane-disrupting toxins.
The protozoan that causes malaria is transmitted to humans by the bite of an insect in the genus Anopheles. What kind of insect is Anopheles?
mosquito
Dengue fever is transmitted by which of the following?
mosquitoes
The most frequently used portal of entry for pathogens is the
mucous membranes of the respiratory tract.
Polio is transmitted by ingestion of water contaminated with feces containing polio virus. What portal of entry does polio virus use?
mucous membranes only
In the human intestinal tract, E. coli produces vitamins beneficial to the host and can inhibit pathogen growth. In turn, the bacterium is supplied with nutrients and an environment for growth. This symbiotic relationship between E. coli and its host is an example of __________.
mutualism
Influenza viruses are classified according to their hemagglutin and __________ proteins.
neuraminidase
Emergence of infectious diseases can be attributed to all of the following
new strains of previously known agents. antibiotic resistance. climatic changes. ease of travel.
Thymine dimers result from
nonionizing radiation.
What is another name for stop codons?
nonsense (stop) codon
A base substitution that changes a codon coding for an amino acid to a stop codon is called a
nonsense mutation.
Which of the following can contribute to postoperative infections?
normal microbiota on the operating room staff using syringes more than once antibiotic resistance errors in aseptic technique
Following coronary artery bypass surgery, seven patients develop Rhodococcus bronchialis infections. Cultures of the operating rooms, Nurse A, and Nurse B are taken. R. bronchialis grows from the hand and nasal swabs of Nurse A. The patients' infections are an example of a/an __________.
nosocomial infection
Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery. This is an example of a
nosocomial infection
Health care professionals who fail to use aseptic techniques can cause __________.
nosocomial infections
Nucleotides
nucleotides that make DNA consist of the sugar, deoxyribose, a phosphate group and a nitrogenous base. The nitrogenous bases that make up DNA are adenine, guanine, cytosine and thymine. In addition to the chromosomal DNA, certain bacteria can have much smaller circular pieces of extrachromosomal DNA (=DNA not associated with the chromosome) called a plasmid.
Which of the following contributes to the virulence of a pathogen?
numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production
Which method cannot be used to culture viruses in a laboratory?
nutrient agar culture media
If a patient has a deep tissue infection as the result of an animal bite on the arm, the portal of entry is described as the __________.
parenteral route
Which of the following is the third stage of a disease?
period of illness
Bordatella pertussis is the etiological agent of ___________, and Neisseria meningitidis is the etiological agent of ____________.
pertussis (whooping cough), meningococcal meningitis
The definition of lysogeny is
phage DNA is incorporated into host cell DNA
During the bacteriophage lysogenic cycle, __________.
phage DNA is inserted into the host chromosome
An organism's inheritable traits that are physically observed is its _____________.
phenotype
A clear area against a confluent "lawn" of bacteria is called a
plaque.
Which of the following is an example of a cloning vector?
plasmid
Which disease is correctly matched with the common portal of entry?
poliomyelitis; mucous membranes of gastrointestinal tract
Recombinant DNA can be introduced into a host cell by any of the following methods EXCEPT __________.
polymerase chain reaction
PCR stands for
polymerase chain reaction.
In which of the following diseases can gender be considered a viable predisposing factor?
urinary tract infections
Escherichia coli belongs to the
proteobacteria.
Ribosomes contain which of the following?
rRNA
What type of RNA forms an integral part of the ribosome?
rRNA
Which of the following is the best reason to classify Streptococcus in the Lactobacillales?
rRNA sequences
The phylogenetic classification of bacteria is based on
rRNA sequences.
Which one of the following is a zoonosis?
rabies tapeworm Hantavirus pulmonary syndrome cat-scratch disease
Placing the DNA from an animal cell into the genome of a bacterium will allow the bacterium to produce an animal product. This new piece of DNA is referred to as __________.
recombinant DNA
Which is NOT a characteristic of the normal microbiota?
regularly associated with disease symptoms
Which of the following cytopathic effects is cytocidal?
release of enzymes from lysosomes
Rickettsias differ from chlamydias in that rickettsias
require an arthropod for transmission
A frameshift mutation in a gene encoding a protein usually __________.
results in the production of a nonfunctional peptide
What type of microbe contains the enzyme "reverse transcriptase"?
retrovirus"—which is an RNA containing virus.
A virus may contain any of any of the following EXCEPT (a) _________
ribosomes
Which would be the most UNLIKELY location to find adhesin molecules on a newly discovered bacterium?
ribosomes
Blood agar would be the culture medium of choice if one were testing a patient for which of the following?
scarlet fever
Multiple fission, which is also called _________, produces cells with the identical DNA of the parent, but they are much smaller in size due to dividing the cytoplasm among multiple nuclei.
schizogony
The occurrence of streptococcal bronchopneumonia in an individual recovering from influenza is an example of a __________.
secondary infection
Overuse and misuse of antibiotics has __________.
selected for antibiotic-resistant strains of bacteria and increased their frequency in both the hospital environment and the community
Endotoxins in sterile injectable drugs could cause
septic shock symptoms
In polio virus replication, the function of the antisense (- strand) RNA is to __________.
serve as a template for the production of sense (+ strand) RNA
Clostridium difficile causes severe diarrhea that is associated with the altering of intestinal microbiota by ___________.
severe diarrhea; associated with the altering of intestinal microbiota by antibiotics
An example of a latent virus infection is _________
shingles
A good cloning vector __________.
should have a gene or genes that allows for selection of transformed host cells
A mutation that affects the genotype of the organism but not the phenotype is called a
silent mutation
Assume you have discovered a cell that produces a lipase that works in cold water for a laundry additive. You can increase the efficiency of this enzyme by changing one amino acid. This is done by
site-directed mutagenesis.
How might a virus pick up a human oncogene?
specialized transduction
Which of the following processes is involved in the production of diphtheria toxin by C. diphtheria or erythrogenic toxin by Streptococcus pyogenes?
specialized transduction
A new microorganism has been discovered that resides in the mouths of dogs. This microorganism lacks a nucleus, has a cell wall consisting of peptidoglycan and an outer membrane of lipopolysaccharide, is shaped like a corkscrew, and is motile by means of an axial filament. This organism is most likely related to __________.
spirochaetes
All of the following bacteria are motile. Which does NOT have flagella?
spirochetes
Pasteurization was first developed to kill __________ in wine.
spoilage bacteria
Mice that are injected with only the R strain of Streptococcus pneumoniae
stay healthy, because their immune systems can kill this strain easily.
A Gram stain is performed on a bacterial sample and the result for Step 1 is a Gram positive organism. According to the key, which step would you go to next?
step 2
Bacteria that cause periodontal disease have adhesins for receptors on streptococci that colonize on teeth. This indicates that
streptococcal colonization is necessary for periodontal disease.
According to the operon model, for the synthesis of an inducible enzyme to occur, the
substrate must bind to the repressor
Symptoms of intense inflammation and shock occur in some gram-positive bacterial infections due to
superantigens.
How would you recognize an antibiotic-producing soil bacterium on a plate crowded with other bacteria? The bacterial colony producing the antibiotic would be __________.
surrounded by a clear area
Which of these conditions would NOT affect the ability of Streptococcus mutans to attach to teeth?
the absence of Actinomyces, a bacterium that can be part of dental plaque
Members of the Adenoviridae cause __________.
the common cold
A persistent infection is one in which
the disease process occurs gradually over a long period.
The ID50 is
the dose that will cause an infection in 50 percent of the test population.
The usefulness of antibiotics is hampered by __________.
the emergence of antibiotic-resistant bacteria
Which of the following factors is believed to limit the size of most bacterial cells?
the fact that nutrients must enter the cells by simple diffusion
Genetic technology has enabled screening for a variety of genetic conditions, and use of this technology is becoming more widely available. Which of the following is likely to become an important issue that will need to be addressed?
the need for legislation to protect the privacy of individuals' genetic information
The morbidity rate is best defined as __________.
the number of individuals, relative to the population, affected by a particular disease in a period of time
You observe large ( >10 micrometer) oval cells in a sputum sample from a patient. Your culture of the sample reveals fuzzy filamentous colonies. You conclude that _
the patient has an infection caused by a dimorphic fungus
All of the following statements are true of yeasts EXCEPT that __________.
they always cause disease
All of the following are characteristic of lichens EXCEPT
they are a symbiotic relationship between a fungus and a protozoan.
All of the following statements are true of the fungi EXCEPT that ________.
they are strict aerobes
The cells of plasmodial slime molds can grow to several centimeters in diameter because
they distribute nutrients by cytoplasmic streaming
Symptoms of protozoan and helminthic diseases are due to
tissue damage due to growth of the parasite on the tissues, waste products excreted by the parasite, and products released from damaged tissues.
The Ames test is used _______
to determine if a chemical is mutagenic and possibly carcinogenic
In which of the following cases would the Limulus amebocyte lysate (LAL) assay be used?
to ensure that a sterilized medical device is free of endotoxin
Which of the following is NOT a purpose of genetic modification?
to remove antibiotic resistant plasmids from bacteria
Assume you have isolated an unknown virus. This virus has a single, positive sense strand of RNA, and possesses an envelope. To which group does it most likely belong?
togavirus
Nonpathogenic Vibrio cholerae can acquire the cholera toxin gene by
transduction.
Conjugation differs from reproduction because conjugation
transfers DNA horizontally, to nearby cells without those cells undergoing replication.
Your lab partner has mixed a dead tryptophan+ strain of Bacillus subtilis with a live tryptophan- strain and observes that her B. subtilis culture is now tryptophan+. The most likely explanation for this is __________.
transformation
After the attachment and entry of a virus into a host cell, what is the next step in the multiplication of animal viruses?
uncoating
You have isolated a bacterium that grows in a medium containing an organic substrate and nitrate in the absence of oxygen. The nitrate is reduced to nitrogen gas. You can be sure that this bacterium is
using anaerobic respiration.
The rise in herd immunity amongst a population can be directly attributed to
vaccinations.
Self-replicating DNA used to transmit a gene from one organism to another is a
vector.
Cytopathic effects are changes in host cells due to
viral infections.
As a health care worker, you are keenly aware of how important it is to avoid harming patients. You worry about inadvertently transmitting an infectious disease to an already compromised individual. According to the CDC, what is the most important thing you can do to avoid this?
wash my hands before interacting with any patient
Auxotrophs ______
will not grow on a plate that lacks the growth factor, but will grow on a complete medium that contains the growth factor
"Naked" viruses lack what structural component?
without an envelop.
Unicellular, nonfilamentous fungi are known as __________.
yeasts
Agarose gel electrophoresis uses _________________ to separate fragments of DNA.
•DNA separated using electrical charge DNA is separated from the template and primer DNA using a technique called electrophoresis.
What disease is caused by the viruses belonging to the viral family from question 3?
•Lentivirus (HIV) •Oncoviruses
What is the designation given to gram- negative rods belonging to the class gammaproteobacteria that live in the GI tract?
•Proteobacteria: largest taxonomic group of bacteria -They are thought to have arisen from a common photosynthetic ancestor
