Microbiology Final Exam
Botulin, the toxin of botulism is: A. not as virulent as tetanospasmin. B. detected and diagnosed by analyzing a patient's blood. C. the cause of rigid paralysis. D. only produced under anaerobic conditions. E. produced when spores germinate in the intestines of adults after ingesting contaminated food.
. only produced under anaerobic conditions.
What is the minimum number of phage that can initiate the development of a plaque in a bacterial lawn?
1
Place the steps of sporulation in order
1) Replication of DNA 2) In-folding of the plasma membrane to enclose a copy of DNA, forming forespore and septum 3) Engulfment of the forespore with a second membrane 4) Deposition of spore complex 5) Spore coat formation 6) Maturation and release of endospore
Place the steps of biofilm formation in the correct order.
1) Surface (substratum) is preconditioned by environmental molecules. 2) Microbes attach and detach from the preconditioned surface. 3) Quorum sensing and the establishment of the extracellular matrix commences as microbes attach more stably. 4) Biofilm matures and some microorganisms escape to the planktonic state.
Virion size ranges from
10-400 nm.
A molecule of RNA has 99 phosphodiester bonds connecting __________ ribonucleotides.
100
Complete transfer in an Hfr F- mating takes approximately _____ minutes.
100
At 4:00 p.m. a closed flask of sterile broth is inoculated with 10,000 cells. The lag phase lasts 1 hour. At 9:00 p.m. the log phase culture has a population of 65 million cells. The approximate number of generations that has occurred is
13
If 20% of the nucleotides in the DNA of a particular organism contain thymine, estimate the percentage of cytosine that is present in the DNA.
30%
The aminoglycosides and tetracycline specifically target the ______________ interfering with _______________.
30s ribosomal subunit; protein synthesis
Which is incorrect regarding Q fever? A. Transmitted by lice B. Pathogen produces resistant spores C. Humans infected from unpasteurized milk and airborne spread D. Causes fever, muscle aches, rash, and sometimes pneumonia E. Is a zoonosis
A. Transmitted by lice
Typhoid fever has the following characteristics, except A. it is spread by ingestion of food contaminated with animal feces. B. it is transmitted by ingesting fecal contaminated food and water. C. it can cause chronic carriers to have pathogens in their gallbladder. D. it can infect the small intestine with fever, diarrhea, and abdominal pain. E. it can become a septicemia, spread to lymph nodes and spleen, and cause liver abscesses.
A. it is spread by ingestion of food contaminated with animal feces.
The most immediate and important treatment needed to prevent death in Cholera victims is A. water and electrolyte replacement. B. antimicrobics. C. antitoxin. D. surgery. E. None of the choices are correct.
A. water and electrolyte replacement.
During the stringent response, ppGpp-regulated genes for amino acid biosynthesis have a(n) _________-rich promoter, this forming a ________ open initiation complex.
AT-rich; more stable
Which of the following is not a termination codon?
AUG
Cell-to-cell communication by quorum has been shown to be important in the regulation of genes needed for
All of the choices are correct.
Which of the following must a pathogen possess in order for it to be successful at causing infectious disease?
All of the choices are correct.
Which of the following play a role in the diagnosis of syphilis?
All of the choices are correct.
Which of the following is an example of gene regulation at the posttranslational level?
Alteration of protein structure.
Which is incorrect about Leptospirosis? A. It can be avoided by not swimming in livestock watering ponds. B. A vaccine is not available. C. Its principle targets are the kidneys, liver, brain, and eyes. D. It is a zoonosis. E. Weil's syndrome occurs during the second phase of the disease.
B. A vaccine is not available.
This organism can infect deeper wound sites and produce exotoxins, enzymes, and gas that cause tissue and muscle necrosis: A. Clostridium botulinum B. Clostridium perfringens C. Clostridium difficile D. Clostridium tetani E. All of the choices are correct.
B. Clostridium perfringens
Production of enterotoxin is a characteristic of: A. Clostridium botulinum. B. Clostridium perfringens C. Clostridium difficile. D. Clostridium tetani. E. All of the choices are correct.
B. Clostridium perfringens.
A pregnant woman is told she has a positive CAMP test and should be treated with a course of antibiotics and globulin. This test is indicative of A. Group A streptococci. B. Group B streptococci. C. S. saprophyticus. D. S. epidermidis. E. S. aureus.
B. Group B streptococci.
Which fastidious genus requires hemin (X factor) and NAD (X factor) in its growth medium? A. Legionella B. Haemophilus C. Brucella D. Shigella E. All of the choices are correct.
B. Haemophilus
The disease anthrax is caused by a species belonging to which genus?
Bacillus
Which of the following is not true about Kirby-Bauer disk diffusion method?
Bacteria used to swab plate should be at least a week old.
Which of the following is a correct comparison between RNA polymerase holoenzyme that functions in transcription and the primase enzyme that functions in DNA replication?
Both enzymes synthesize RNA.
How many experiments done by Griffith similar to those done by Avery, MacLeod, and McCarty?
Both used pneumococcal bacteria.
A traveler returning to the the United States from India reported having a fever and severe joint pain. She mentioned that the mosquitoes had been particularly troublesome during her trip, and that she had taken the appropriate prophylactic anti-malarial medications. What is a likely cause of her illness?
Chickungunya fever
Ornithosis is caused by
Chlamydophilia psittaci
Which of the following are other names for yaws? A. Bouba B. Frambesia tropica C. Patek D. All of the choices are correct. E. None of the choices are correct.
D. All of the choices are correct.
Which color pigment is produced by Pseudomonas aeruginosa? A. Lemon yellow B. Red-orange C. Golden D. Blue-green E. Pale orange
D. Blue-green
Lyme disease is caused by __transmitted by ticks. A. Proteus vulgaris B. Rickettsia typhi C. Rickettsia rickettsii D. Borrelia burghdorferi
D. Borrelia burghdorferi
Production of a neurotoxin that binds to target sites on spinal cord neurons responsible for inhibiting skeletal muscle contraction is a characteristic of: A. Clostridium botulinum. B. Clostridium perfringens. C. Clostridium difficile. D. Clostridium tetani. E. All of the choices are correct.
D. Clostridium tetani.
Scarlet fever is caused by strains of: A. Staphylococcus aureus. B. Staphylococcus epidermidis. C. Staphylococcus saprophyticus. D. Streptococcus pyogenes. E. Streptococcus agalactiae.
D. Streptococcus pyogenes.
All of the following are correct about primary atypical pneumonia except A. it is mainly caused by Mycoplasma pneumoniae. B. it can also be caused by adenoviruses. C. it is transmitted by aerosol droplets. D. it has symptoms similar to pneumococcal pneumonia. E. community resistance is high.
D. it has symptoms similar to pneumococcal pneumonia.
Escherichia coli infections A. are often transmitted by fecal contaminated water and food. B. include urinary tract infections from normal flora strains. C. involve enterotoxin in traveler's diarrhea. D. can cause an inflammatory disease similar to Shigella dysentery. E. All of the choices are correct.
E. All of the choices are correct.
Helicobacter pylori causes A. gastritis. B. duodenal ulcers. C. stomach ulcers. D. increased risk for stomach cancer. E. All of the choices are correct.
E. All of the choices are correct.
Legionella pneumophila A. requires special lab growth media. B. often lives in close associations with amoebas. C. causes fever, cough, and diarrhea. D. causes a severe pneumonia. E. All of the choices are correct.
E. All of the choices are correct.
Lyme disease involves A. early symptoms of fever, headache, stiff neck. B. crippling polyarthritis and cardiovascular and neurological problems. C. people having contact with wooded or forested areas. D. treatment with antimicrobics. E. All of the choices are correct.
E. All of the choices are correct.
Streptococcus pyogenes causes all the following, except: A. necrotizing fasciitis. B. erysipelas. C. impetigo. D. scarlet fever. E. scalded skin syndrome.
E. scalded skin syndrome.
All of the following are correct about salmonelloses except A. non-typhoidal strains of salmonella are zoonotic in origin B. foods contaminated by rodent feces may cause outbreaks. C. outbreaks have been caused by eggs. D. drug resistance of salmonella is on the rise. E. strains are normal flora in dogs and cats.
E. strains are normal flora in dogs and cats.
The use of arsenic compound Salvarsan as a treatment for syphilis is credited to
Ehrlich.
All fastidious microorganisms require which of the following for growth?
Extra nutrients (such as whole blood)
Which of the following is not true of viroids?
Extracellular viroids have a lipid bilayer envelope.
In an F+ F- conjugation, the donor is the __________ strain.
F+
After an F+ F- mating, the donor is __________ and the recipient is __________.
F+ ; F-
A PrPC protein can convert a PrPSc to a PrPC.
False
Bacteria isolates from post surgical infections of several patients on the same hospital floor demonstrate an increase in resistance to similar antibiotics. The pattern of antibiotic resistance in these cases is most likely due to vertical gene transfer among bacteria that carry resistance genes to bacteria that lack those genes.
False
Bacterial viruses are so named because they have prokaryotic cell structures similar to their bacterial hosts.
False
Bacteriophage therapy was developed after antibiotics were first discovered and used for treating bacterial infections.
False
Botulism is often referred to as lockjaw.
False
During the assembly of the flagellar filament, the flagellin protein monomers assemble at the cell proximal base of the flagellum.
False
During the lag phase of microbial growth, the cells are metabolically inactive.
False
Endospores are reproductive structures.
False
In terms of membrane lipids, the plasma membranes of archaeons are more similar to those of the eukaryotes than to membranes of bacteria.
False
Phosphorus can be obtained from organic sources only.
False
Stable integration of foreign DNA into a bacterial host genome is generally accomplished through induced plasmid transformation than by natural uptake of free DNA fragments.
False
Streptococcus pneumoniae is the most prevalent Gram-negative bacterium isolated from pneumonia patients.
False
Streptokinase causes the symptoms of scarlet fever.
False
The presence or absence of an envelope is not useful in classifying viruses because any given virus may at one time have an envelope at another time not have an envelope.
False
When two different microbes are engaged in a cooperative relationship, they do as well when living separately as they do when living together.
False
Zinc (Zn) is considered a macronutrient.
False
Using the ICTV taxonomy system, a virus name ending in "viridae" would be part of which grouping?
Family
Which kind of sterilization procedure takes advantage of the size of microorganisms?
Filtration
Unlike Sulfolobus, some Archaea use _________ protein(s) to accomplish cytokinesis.
FtsZ
Which etiologic agent is associated with an infection resulting in a copious frothy fishy-smelling vaginal discharge?
Gardnerella vaginalis
Rubulavirus falls under which group of the ICTV nomenclature system?
Genus
Who is generally credited with the discovery of sulfanilamide as a chemotherapeutic agent?
Gerhard Domagk
Women of childbearing age should be vaccinated against __________.
German measles
___________ is the main part of the process through which a vegetative cell is formed from an endospore.
Germination
In tuberculosis, when a caseous lesion calcifies, it is called a _____________.
Ghon complex
Which of the following organelles is involved in modification, packaging, and secretion of materials?
Golgi apparatus
Endotoxin is released when
Gram negative pathogens lyse or divide.
The type of filter used in a laminar flow biological safety cabinet is called a(n) __________ filter.
HEPA (high efficiency particulate air)
Which of the following is not part of the process by which an endospore transforms to become a vegetative cell?
Induction
Which of the these transposable elements do not carry genes for functions other than those needed for transposition?
Insertion sequences
Which of the following is true of the integration of a viral genome into the host chromosome?
Integration of the viral genome is a form of site-specific recombination.
As pertaining to the spread of antibiotic resistance in bacteria, which of the following terms is not directly related to the others?
Intercalate (Cassette, Integron, Integrase)
Several new materials have been developed for use in the microbiology lab. These materials must be sterilized before use, but cannot withstand a temperature over 60 C and can't be exposed to water. Which method of sterilization would be applicable?
Ionizing radiation
What would be the hypothetical outcome if the action of RecA were inhibited during the SOS response?
LexA would not autolyse, and therefore the transcription of DNA repair genes would not occur.
An experiment was done to determine the decimal reduction time of a specific population of organisms at 80 C. The data is indicated by an arrow on the graph. Which labeled line represents the likely results if the experiment was repeated at the same temperature, but starting with a larger number of organisms?
Line C
Which of the following does not transmit the AIDS virus?
Mosquitoes
__________ are glycoprotein spikes protruding from the outer surface of the viral envelope.
Peplomers
Which of the following protects bacteria from lysis in dilute solutions and helps to determine their cellular morphology or shape?
Peptidoglycan
Which of the following is most likely synthesized on free ribosomes?
Polypeptide chains that form enzymes which function in glycolysis
The most notable difference between PrPC (normal protein) and PrPSc (prion protein) is
PrPC folds appropriately whereas PrPSc does not fold correctly.
Which of the following antibiotics specifically inhibits DNA synthesis?
Quinolones
The simplest viruses consist of
RNA or DNA in a protein coat.
In terms of relatedness to a specific cellular process, which protein does not belong with the others?
RNA polymerase holoenzyme
Most drugs used to slow the progress of AIDS fall into which of the following categories?
Reverse transcriptase and protease inhibitors
Which of the following is an autoimmune disease?
Rheumatic fever
_________ are the site of protein synthesis in the cell.
Ribosomes
__________ are the site of protein synthesis in the cell.
Ribosomes
Modify the following statement to make it correct: Ribozymes are ribonucleosomes used by bacteria and eukaryotic cells to modify DNA.
Ribozymes are ribonucleases used by bacteria and eukaryotic cells to modify RNA.
All of the following are reasons why some scientists believe that the term "prokaryote" is a somewhat artificial designation and should be discarded except
Some bacteria have 80S ribosomes.
Rickettsia rickettsii are readily phagocytized by macrophages. Why doesn't this control the infection and prevent the development of Rocky Mountain spotted fever?
The bacteria escape from the phagosome and reproduce in the cytoplasm of the phagocyte.
Motile bacteria have been placed in an environment with a gradient of a chemical attractant. Which of the following behaviors would you predict?
The bacteria will both reduce tumbling frequency and increase run duration in the direction of the chemical.
What would be the most likely outcome if the genetic code was not degenerate?
The effect of some mutations would increase.
Which is a false statement regarding riboswitches?
The effector molecules that bind to riboswitches are proteins.
Which of the following conclusions can be made if two identical insertion sequences are identified in separate locations on a chromosome?
The insertion sequence was transferred via replicative transposition.
What is the key factor determining whether or not attenuation will occur when transcription of the E. coli trp operon has been initiated?
The level of trp-tRNA that is changed with tryptophan
A pathogenic bacterial species has mutated and is no longer able to synthesize a capsule. Which outcome would you predict?
The mutated bacteria will not be able to cause disease as readily.
If one reproductive strategy of a eukaryotic organism is gamete fusion, what can be concluded about that organism?
The organism participates in vertical gene transfer.
Which of the following is useful in distinguishing between prokaryotic and eukaryotic cells?
The presence of membrane-delimited organelles within the cytoplasm
Which statement best summarizes the major distinction between horizontal gene transfer and vertical gene transfer?
The recipient of genes in horizontal transfer is a mature cell, whereas the recipient of genes in vertical transfer is a progeny cell.
What is the result of successful communication between rhizobia and their plant hosts?
The rhizobia invade the plant root and begin to fix nitrogen with the assistance of the plant.
Which of the following is most similar between the cell cycle process of Sulfolobus and that of bacteria?
The segregation of the chromosomes.
Which is false regarding the two-component regulatory system in bacteria?
The sensor kinase is phosphorylated by the response regulator when the extracellular environment changes.
Almost all known plant viruses are RNA viruses.
True
Bacteria in biofilms are often more difficult to treat with antibiotics than planktonic bacteria.
True
Bacteria with DNA described as having "hairpin ends with inverted repeats" must not have circular chromosomes.
True
DNA of thermophiles is stabilized by binding of special nucleoid-associated proteins.
True
DNA polymerase and aminoacyl-tRNA synthase are similar in that both have proofreading ability, but differ in the substrates that they act upon.
True
Enveloped viruses may enter their host cells by engulfment within coated vesicles (endocytosis).
True
Enveloped viruses may enter their host cells by fusion of their envelope with the cytoplasmic membrane, thereby depositing their nucleocapsid within the cell.
True
Escherichia coli O157:H7 is a major cause of hemorrhagic colitis in the United States.
True
One way in which organisms may exhibit resistance to a drug is the ability to pump the drug out of the cell immediately after it has entered.
True
One way in which small viruses package more information into a very small genome is to use overlapping genes so that the same base sequence is read in more than one reading frame.
True
One way that the development of drug resistance in viruses has been reduced has been by the use of a cocktail of several drugs at high doses.
True
One way to regulate gene expression is through the production of different sigma factors. These cause RNA polymerase to bind to different sets of promoters, thereby altering the pattern of gene expression.
True
Tetanus can be prevented with the DTaP childhood immunization and boosters of the tetanus toxoid.
True
The DNA of some archaeons is stabilized by association with archaeal histone proteins forming particles resembling eukaryotic nucleosomes.
True
Transformation has been observed in only a limited number of species in nature, but we have found ways to force the process upon other species in the labratory.
True
Ultraviolet radiation is an effective means of sterilizing surfaces.
True
All of the following situations are passive modes of penetration for the invasion of host tissues by opportunistic pathogens EXCEPT
a bacterium adhering to intravenous tubing, forming a biofilm
One example of infectious disease transmittion by a fomite is
a child developing a cold after playing with a toy that harbored rhinovirus.
Bacillus anthracis strains can be separated into five categories based on
a genetic assay that detects variable numbers of tandem repeats in various genes.
Which will require a longer time to kill?
a larger population of microorganisms
A change in genotype, but not in phenotype, is most likely due to
a point mutation in the third position of a DNA triplet.
The E test is
a quantitative antibiotic sensitivity test that utilizes plastic strips impregnated with an antibiotic of interest.
A lysosome containing undigested material is called
a residual body
Diagnosis of West Nile virus infection is through detection of
a rise in neutralizing antibody in a patient's serum.
Under normal circumstances, the microbiota of the skin is kept in check by
a slightly acidic pH
Organisms that have their optimum growth pH between 0.0 and 5.5 are called ___________.
acidophiles
When arabinose is present in the environment, the AraC protein acts as a(n) ______________ for the E. coli ara operon.
activator or inducer
Nutrients can be concentrated from dilute solutions by
active transport and group translocation.
The movement of molecules across a membrane from an area of lower concentration to an area of higher concentration with the expenditure of energy is called
active transport.
All of the following are reverse transcriptase inhibitors used to treat HIV infection EXCEPT
acyclovir.
Organisms that ignore oxygen are grow equally well in its presence are called
aerotolerant.
For surface cultivation of microorganisms, a sulfated polymer called agar can be extracted from _______ and added to liquid media in order to cause it to solidify.
algae
Organisms that have their optimum growth pH between 8.5 and 11.5 are called _____________.
alkaliphiles
Alternate forms of genes resulting from mutations are called
alleles.
A unidirectional process where a specific compound is released by one organism has a negative effect on another organism is called
amensalism.
Aminoacyl-tRNA synthetases catalyze covalent addition of _____________ ________________ to tRNAs.
amino acids
Buchnera aphidicola provides ___________ to its aphid host that are essential to the survival of the insect.
amino acids
In many spirochetes, multiple flagella combine to form a bundle known as a(n) ____________ fibril, which winds around the cell and confers motility on the cell.
axial
An arrangement of microtubules located in the matrix of cilia and flagella is called the
axoneme
Complex microbial communities that grow tightly adhered to surfaces are called __________.
biofilms
The Sec system is used by
both Gram-positive and Gram-negative bacteria.
An open system in which the growth rate is maintained by adding a nutrient (present in limiting quantities) at the same rate that medium containing microorganisms is removed is called a
chemostat.
Acute viral gastroenteritis is the leading cause of death in
children in developing countries.
The disinfectant of choice for municipal water supplies is __________.
chlorine
Drugs are used to treat malaria include
chloroquine and qualaquin.
If flagellar rotation of Escherichia coli cells is _________, then CheA is _________.
counterclockwise; unphosphorylated
In humans the most common type of anthrax disease is
cutaneous anthrax resulting from the introduction of spores into a break in the skin.
Microscopic or macroscopic degenerative changes or abnormalities in infected host cells and tissues are called __________ ____________.
cytopathic effects
The liquid component of the cytoplasm is known as the
cytosol
A relationship in which one organism is found on the surface of another is referred to as a(n) _____________.
ectosymbiosis
A plasmid that can either exist independently of the chromosome or be integrated into it is called a(n) __________.
episome
An acute infection and inflammation of the dermal layer of the skin is ________.
erysipelas
The two most important alcohol germicides are _________ and ____________.
ethanol; isopropanol
Enzymes that are secreted out of the cell to aid in the acquisition and digestion of environmental nutrients are called __________.
exoenzymes
A DNA molecule that enters a bacterium by one of several mechanisms is called a(n)
exogenote.
Microorganisms are most nearly uniform in terms of chemical and physiological properties during ________ phase.
exponential
Glycoprotein spikes protruding from the outer surface of viral envelopes function as
factors that bind to host cells.
An inanimate object that may be contaminated with a pathogen is called a ________.
fomite
The main route of transmission of the poliovirus is _______________.
food and water
The Y-shaped part of the DNA molecule where the actual replication process occurs is called the replication ____________.
fork
The antimicrobial action of artemisinin is not well understood but this chemical appears to
form reactive oxygen intermediates inside Plasmodium-infected red blood cells.
A mutation from the most prevalent form of a gene to a mutant form is called a __________ mutation.
forward
An agent that specifically kills fungi but not other kinds of microorganisms is also known as a
fungicidal agent.
Humans may contact psittacosis by
handling infected birds and the dried excreta of birds.
In lichens, the fungi send projections of their hyphae across the algal cell wall in order to obtain nutrients from the photosynthetic partner. These projections are called
haustoria.
The Ebola virus causes ________.
hemorrhagic fever
The leading reason for liver transplantation in the United States is ________.
hepatitis C
Cold sores or fever blisters are caused by the ______ _________ virus.
herpes simplex
Intracellular granules of organic or inorganic material that are stockpiled by bacteria for future use are called ______________.
inclusions
Transition mutations can result from
incorporation of a base analog that exhibits different base-pairing properties from the base it replaces and chemical modification of an existing base in the DNA so that in the next round of replication it will pair differently from the unmodified base.
Transfer of pathogens from host to environment and then to another host are said to be transmitted _____________.
indirectly
Once a pathogen has infected the host, __________________ is a measure of the pathogen's ability to spread to adjacent or other tissues.
invasiveness
Many of the enzymes found in virus particles are
involved in the replication of viral nucleic acid.
Iodine can be complexed with an organic carrier to from water-soluble, stable complexes called __________ , which release iodine slowly and eliminate skin burns and irritation associated with iodine use.
iodophors
All of the following may result from overgrowth of Clostridium difficile in the large intestine EXCEPT
large volumes of rice-water stools
Enzymes needed to digest all types of macromolecules are found in
lysosomes.
Some species of aquatic bacteria use inclusion bodies known as ________ to orient themselves in Earth's magnetic field.
magnetosomes
Organisms that are damaged by the normal atmospheric levels of oxygen (20%) but require oxygen at levels of 2-10% are called
microaerophiles.
In an enveloped virus, the part of the virus including the nucleic acid genome and the surrounding protein coat but not the envelope is called the
nucleocapsid.
Organisms that can grow in habitats with low water activity by maintaining a high internal salt concentration are called ________ organisms.
osmotolerant
Mumps is caused by a __________.
paramyxovirus
Heliobacter pylori is a principal causative agent of
peptic ulcer disease
The plasma membranes of eukaryotes contains all of the following EXCEPT
peptidoglycan
Repair of thymine dimers using light to split the dimers apart into separate monomers is called
photoreactivation.
Many types of bacteria are only ______ when dispersing from more stable and heterogeneous communities known as biofilms.
planktonic
Viroids are of economic significance because they cause disease in
plants.
A __________ assay is most useful for determining the viability of a viral preparation.
plaque
Bacteria that do not have a fixed shape are said to be ___________.
pleomorphic
Messenger RNA molecules that direct the synthesis of more than one polypeptide are said to be ______________.
polycistronic
A complex consisting of a single mRNA molecule with several ribosomes is called a
polysome.
Viral capsid protein subunits are called
protomers.
The nucleolus plays a major role in synthesis of
rRNA.
Transposons that insert at a new location while a copy remains at the original location are said to mediate _______________ transposition.
replicative
Host __________ is the process by which some cells are capable of degrading an exogenote.
restriction
The bacterium E. coli swims in a straight line, called a _________, for a few seconds; then it stops, tumbles, then swims away in a new direction.
run
Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes). Among the halophiles, mannitol fermenters will produce acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol fermenter, a nonhalophilic mannitol fermenter, and a halophilic mannitol nonfermenter. In this case, the medium is acting as a _______ medium.
selective and differential
An antimicrobial drug that inhibits the growth of bacteria without affecting the growth or function of cells in the human host is described as being ________________________.
selectively toxic
Viroids are:
short infectious single stranded RNAs that can infect some plants.
Pathogenic staphylococci inhibit neutrophil chemotaxis, phagocytosis, and the action of vancomycin by the production of _________.
slime
When comparing dry heat and moist heat sterilization, dry heat is
slower.
When the cell wall is removed from a Gram-negative bacterium without removing the outer membrane, the resulting form is called a(n) __________.
spheroplast
Rigid bacteria with a helical cell shape are called
spirilla.
Flexible bacteria with a helical shape are called
spirochetes.
All of the following are characteristics of spread plates EXCEPT
spread plates that readily grow anaerobic bacteria.
The terminator versus anti-terminator function of the T box-based riboswitch used by Gram-positive bacteria to regulate amino acid-related genes is determined by
the binding of the appropriate uncharged tRNA.
Hemagglutination is
the clumping together of red blood cells in the presence of a viral suspension.
The reason coral reefs are among the most productive and successful ecosystems is due to
the coral-dinoflagellate mutualistic relationship.
A sharp reduction in the incidence of Haemophilus influenzae serotype b infections is principally due to
the development of an effective vaccine
The most important distinguishing feature of eukaryotes that is lacking in prokaryotes is
the division of the cell into compartments bounded by membranes.
When bacterial genes are transferred to another bacterium by a virus, it is called
transduction.
Some viruses cause abnormal growth of cells rather than destruction. This is called __________.
transformation
When a recipient cell acquires a piece of naked DNA from the environment, it is called
transformation.
The term that refers to those microbes found as symbionts in a short relationship of a nongrowing nature is ____________.
transient
An open system in which the growth rate is maintained by the removal and addition of media at such a rate as to maintain a constant cell density is called a
tubidostat.
The cell wall of bacteria constrains the __________ ___________ that results from the osmolarity of the cytoplasmic contents.
turgor pressure
Ribosomes consist of __________ separate subunits that come together as part of the initiation process and dissociate immediately after termination.
two
The term _______ refers to the degree or intensity of pathogenicity.
virulence
A wide variety of microorganisms are commercially used to manufacture _________ for human consumption.
vitamins
Small organic molecules called __________ function as enzyme cofactors.
vitamins
Development of drug resistance is encouraged by
widespread use of broad-spectrum drugs.
The __________ ___________ is the most prevalent from of a gene in a population.
wild type
The first product to be commercially treated by pasteurization was
wine
In terms of transcription regulation, the role of a helix-turn-helix is most similar to that of a(n) __________.
zinc finger
A ________ infections is a disease caused by a parasitic organism that is normally found in animals other than humans.
zoonotic
Dinoflagellates that exist endosymbiotically within a variety of marine invertebrates are called
zooxanthellae.
Place the events associated with each stage of infectious disease in the correct order with regard to time.
1 Incubation period 2 Prodormal stage 3 Illness period 4 Convalescence
Order the following regions of a gene from the most upstream region (1) to the most downstream region (5).
1) -35 consensus sequence 2) Pribnow box 3) coding sequence 4) rut site 5) terminator
Match the definition with the word. 1) monotrichous 2) peritrichous 3) lophotrichous 4) amphitrichous a) a singe flagellum b) a single flagellum at each pole of an organism c) a cluster of flagella at one or both ends of an organism d) a relatively even distribution of flagella over the entire surface of the bacterium
1-a, 2-d, 3-c, 4-b
Order the following structures (layers) that a small molecule must pass through as it moves from outside of an encapsulated gram negative cell to the cytoplasm
1. Capsule 2. Outer membrane 3. Periplasm and Peptidoglycan 4. Plasma membrane
Place the steps in the correct order to reflect how a lethal dose may be determined.
1. Dilutions of virus are made to represent a range of concentrations. 2. Dilutions are inoculated into susceptible tissue cultures (or susceptible host organisms). 3. Inoculated host cells are observed and the number of dead cells are counted. 4. The dilution which killed 50% of the tissue culture cells is identified.
Place the following steps in the correct order to reflect how a plaque assay is done:
1. Several dilutions of sample to be assayed are prepared. 2. Dilutions are mixed with the appropriate bacterial host. 3. Bacterial/sample dilution mixtures are plated on agar plates. 4. Plates are incubated to allow for plaque development. 5. Plates from different dilutions are examined and plaques are counted.
Order the following statements to correctly describe the route of secreted protein as it is synthesized and secreted from a eukaryotic cell.
1. Translation begins on a ribosome. 2. The ribosome attaches to the rough endoplasmic reticulum and the newly formed polypeptide is pushed into the lumen of the rough ER. 3. The protein folds and undergoes modification within the rough ER. 4. The protein travels within a membranous vesicle from the ER to the cis face of the Golgi apparatus. 5. The protein travels toward the trans face of the Golgi, from which it is packaged into a secretory vesicle. 6. The secretory vesicle travels to and merges with the cell membrane, releasing its contents outside of the cell.
During transcription elongation, how many pyrophosphate molecules are produced from the incorporation of 20 ribonucleoside monophosphates?
20
How many DNA triplets encode 60 amino acids?
20
What is the minimum number of aminoacyl-tRNA synthetase enzymes needed to attach amino acids to all the various tRNA molecules?
20
At 4:00 p.m. a closed flask of sterile broth is inoculated with 10,000 cells. The lag phase lasts 1 hour. At 9:00 p.m. the log phase culture has a population of 65 million cells. The mean generation time is approximately
20 minutes.
Given a log phase bacterial culture with 1x10^6 cells per ml and a generation time of 30 minutes, how long does it take the culture to reach a density of 6.4x10^7 cells per ml?
3 hours
In attenuation regulation of the trp operon, which stem loop forms when tryptophan is readily available to the cell?
3:4
0.2 mls of a 10^-4 dilution of a virus preparation yields 90 plaques. What is the number of PFU per ml in the undiluted virus preparation?
4.5 10^6
The primary lipid components of the membranes of extreme thermophiles are
40 carbon diglycerol tetraethers.
West Nile virus has been detected in _________ states of the United States.
47
How many phosphodiester bonds are needed to join 50 deoxyribonucleotides in a DNA strand?
49
The standard or housekeeping sigma factor used most often by E. coli RNA polymerase under normal growth conditions is called sigma ________.
70
Bacterial and archaeal ribosomes are known as _____ ribosomes, based on their sedimentation coefficient.
70S
Bacterial and archaeal ribosomes are known as ________ ribosomes, based on their sedimentation coefficient.
70S
Prokaryotic DNA replication occurs at a rate of
750-1,000 base pairs per second.
At 4:00 p.m. a closed flask of sterile broth is inoculated with 10,000 cells. The lag phase lasts 1 hour. At 9:00 p.m. the culture enters stationary phase with a population of 65 million cells. At what time is the population half maximal?
8:40 p.m.
Antigenic variation occurs almost yearly with the influenza ____ virus.
A
You have been studying the effect of a concentration gradient on the rate of transport of a nutrient into a bacterial cell. If a carrier protein is involved in the transport of this nutrient, which curve would you expect to see?
A
If a region of DNA contained numerous mismatches due to a modifying agent that caused methylation of guanine, which of the following mutagens is most likely the cause?
A DNA modifier such as an alkylating agent
Choose the description below that best matches the current model of RNA polymerase holoenzyme.
A core enzyme composed of five polypeptides bound by a transcription factor.
In which of the following situations did disease develop due to vertical transmission of the pathogen?
A fetus develops listeriosis after unpasteurized cheese infected with Listeria bacteria is consumed by the mother during pregnancy
A microbiologist studying the human microbiome is interested in how a particular bacterial species may impact water absorption in the large intestine. Which of the following models is appropriate for this investigation?
A germfree mouse raised in a sterile environment.
What might be a reason for the accumulation of improperly folded protein complexes in the bacterial cell cytoplasm following translation?
A problem exists with the functioning of molecular chaperones.
During translation elongation, which event happens last?
A tRNA molecule translocates from the P site to the E site.
What is the causative agent of Farmer's Lung and Bagossis? A. Actinomyces israelii B. Nocardia C. Mycobacterium tuberculosis D. Bacillus anthracis E. Clostridium perfringens
A. Actinomyces israelii
Which is not a characteristic of spirochetes? A. All are pathogenic B. Gram negative C. Helical shape D. Always motile E. Endoflagella enclosed in periplasmic space
A. All are pathogenic
Treponea pallidum subspecies pallidum A. All of the choices are correct. B. has humans as the reservoir. C. can cross the placenta. D. is the cause of syphilis. E. is transmitted by direct sexual contact.
A. All of the choices are correct.
Although Burkholderia cepacia could be very useful in bioremediation programs, it is not feasible to use it. Why? A. Because it can cause opportunistic infections in the respiratory tract. B. Because it cannot be cultured in the lab to necessary numbers. C. Because it is too expensive at this time to grow it. D. It encourages the overgrowth of fungus in the environment, which is not desirable. E. It produces a foul odor making it a poor choice for most situations.
A. Because it can cause opportunistic infections in the respiratory tract.
Production of a neurotoxin that prevents acetylcholine release from motor neurons at neuromuscular junctions is a characteristic of: A. Clostridium botulinum. B. Clostridium perfringens. C. Clostridium difficile. D. Clostridium tetani. E. All of the choices are correct.
A. Clostridium botulinum.
Which is mismatched? A. H antigen - fimbriae B. K antigen - capsule C. O antigen - cell wall, somatic D. All of the choices are correct. E. None of the choices are correct.
A. H antigen - fimbriae
A cause of epiglottitis in children and young adults is A. Haemophilus influenzae. B. Haemophilus ducreyi. C. Haemophilus aegyptius. D. Haemophilus parainfluenzae. E. Haemophilus aphrophilus.
A. Haemophilus influenzae.
Which is incorrect about Mycoplasma pneumoniae? A. It has birds as a reservoir. B. It is a common cause of primary atypical pneumonia. C. Initially causes fever, malaise, sore throat, headache. D. After 2 to 3 weeks, it develops into an unproductive cough and earache. E. Is a bacterial cell without a cell wall.
A. It has birds as a reservoir.
Which is incorrect about Lyme disease? A. It is a new disease that started in Lyme, Connecticut. B. Its reservoirs are mice and deer. C. It is transmitted by ticks. D. It is nonfatal. E. It can slowly progress and mimic rheumatoid conditions.
A. It is a new disease that started in Lyme, Connecticut.
Which disease involves transmission by aerosolized water from whirlpool spas, air conditioners, cooling towers, and supermarket vegetable misters? A. Legionellosis B. Pertussis C. Brucellosis D. Plague E. Traveler's diarrhea
A. Legionellosis
Which of the following is not transmitted via an arthropod vector? A. Leptospirosis B. Lyme disease C. Rocky Mountain spotted fever D. Epidemic typhus
A. Leptospirosis
The white-footed mouse, deer, and deer ticks are important to maintaining the enzootic transmission cycle, associated with A. Lyme disease. B. leptospirosis. C. chlamydiosis. D. Rocky Mountain spotted fever. E. tertiary syphilis.
A. Lyme disease.
The common soil mycobacteria that frequently cause systemic infection and death in AIDS patients is: A. Mycobacterium avium complex (MAC). B. Mycobacterium kansasii. C. Mycobacterium scrofulaceum. D. Mycobacterium fortuitum complex. E. Mycobacterium marinum.
A. Mycobacterium avium complex (MAC).
Which is mismatched? A. Rickettsia rickettsii - epidemic typhus B. Coxiella burnetii - Q fever C. Bartonella quintana - trench fever D. Bartonella henselae - cat scratch disease E. Rickettsia typhi - endemic (murine) typhus
A. Rickettsia rickettsii - epidemic typhus
Which pathogen has drug resistant strains called MRSA? A. Staphylococcus aureus B. Staphylococcus epidermidis C. Staphylococcus saprophytic-us D. Streptococcus pyogenes E. Streptococcus agalactiae
A. Staphylococcus aureus
A common food intoxication is caused by enterotoxin-producing strains of: A. Staphylococcus aureus. B. Staphylococcus epidermidis. C. Staphylococcus saprophyticus. D. Streptococcus pyogenes. E. Streptococcus agalactiae.
A. Staphylococcus aureus.
The majority of otitis media in children is mainly due to infection with: A. Streptococcus pneumoniae. B. Streptococcus pyogenes. C. Branhamella (Moraxella) catarrhalis. D. Streptococcus agalactiae. E. Staphylococcus saprophyticus.
A. Streptococcus pneumoniae.
In patients with diabetes or liver disease, ingestion of raw oysters contaminated with this organism can lead to death: A. Vibrio vulnificus B. Vibrio parahaemolyticus C. Vibrio cholerae D. Campylobacter jejuni E. Helicobacter pylori
A. Vibrio vulnificus
All of the following pertain to gonorrhea, except: A. a chancre-type lesion develops at the portal of entry. B. it is a reportable infectious disease. C. pelvic inflammatory disease (PID) and infertility are complications. D. females can have asymptomatic infection. E. symptoms include painful urination and discharge.
A. a chancre-type lesion develops at the portal of entry.
Which is not correct about Mycobacterium species? A. all species are human pathogens B. cell walls have waxy lipids C. acid fast D. usually have a slow growth rate E. long, slender rods
A. all species are human pathogens
Yaws, Pinta, and Bejel are all diseases that A. are slow, progressive skin diseases that can spread to deep tissues. B. are sexually transmitted. C. are caused by arthropod vectors. D. are caused by Vibrio species. E. are respiratory tract infections.
A. are slow, progressive skin diseases that can spread to deep tissues.
Tuberculoid leprosy: A. causes asymmetrical, shallow skin lesions with loss of pain sensation. B. is the most disfiguring. C. pathogen grows extensively in cooler body areas such as nose, ears, testes. D. complications include secondary infections, kidney, or respiratory failure. E. includes all of these choices.
A. causes asymmetrical, shallow skin lesions with loss of pain sensation.
Rebecca Lancefield differentiated streptococci on the basis of differences in their: A. cell wall carbohydrates in a serological test. B. patterns of hemolysis on blood agar. C. ability to produce catalase. D. gram stain appearance. E. All of the choices are correct.
A. cell wall carbohydrates in a serological test.
Formation of a pseudomembrane in the back of the throat is seen in: A. diphtheria. B. listeriosis. C. tuberculosis. D. erysipeloid. E. botulism.
A. diphtheria.
The pathogenesis of rickettsial infections often involves infection of A. endothelial lining of blood vessels. B. gastrointestinal lining. C. dermis of the skin. D. stomach mucosa. E. urinary tract.
A. endothelial lining of blood vessels.
Up to 70% of travel-associated gastrointestinal diseases are caused by A. enterotoxigenic strains of E. coli. B. Salmonella. C. Shigella dysenteriae D. E. coli 0157:H7. E. enteroinvasive E. coli.
A. enterotoxigenic strains of E. coli.
The Group A streptococcal infection that has symptoms of fever, edema of skin near portal of entry, and an elevated red, hot vesicular lesion is: A. erysipelas. B. impetigo C. necrotizing fasciitis. D. scarlet fever. E. None of the choices are correct.
A. erysipelas.
Which is not a characteristic of Helicobacter pylori? A. gram negative B. produces enteroxin that causes diarrhea C. curved rods D. lives in the stomach E. produces urease that buffers stomach acidity
A. gram negative
The tertiary stage of syphilis A. is when gummas develop in tissues. B. is when the patient is highly infectious to others. C. occurs within 10 days of the primary stage. D. has no symptoms E. is when a chancre develops.
A. is when gummas develop in tissues.
Which of the following is not true about diphtheria? A. it is a zoonosis B. humans can be healthy carriers C. it is prevented with the DTaP vaccine D. it is an upper respiratory infection E. it can be transmitted via contaminated milk
A. it is a zoonosis
All of the following pertain to Clostridium difficile infection, except: A. it is due to ingestion of contaminated, improperly stored, cooked meats and gravies. B. it is a colitis that is a superinfection. C. it often has an endogenous source. D. it may be on the rise due to increased use of gastric acid inhibitors. E. it is major cause of diarrhea in hospitals
A. it is due to ingestion of contaminated, improperly stored, cooked meats and gravies.
All of the following are associated with bubonic plague, except A. it is transmitted by human feces. B. it is caused by Yersinia pestis. C. the patient often has enlarged inguinal lymph nodes. D. the patient has fever, headache, nausea, weakness. E. it can progress to a septicemia.
A. it is transmitted by human feces.
All of the following are characteristics of Campylobacter jejuni except A. it is transmitted through ingestion of contaminated chicken, meat, milk, and water. B. it causes fever and a watery to bloody diarrhea. C. it infects the stomach. D. it produces an enterotoxin called CJT that stimulates diarrhea. E. it has gram negative curved rods with darting motility.
A. it is transmitted through ingestion of contaminated chicken, meat, milk, and water.
E. coli 0157:H7 characteristics include all the following, except: A. it only causes occupational illness in people who work with animals. B. it is transmitted by ingestion of contaminated, undercooked food, especially hamburger. C. it causes a bloody diarrhea. D. it is reservoir is cattle intestines. E. some cases go on to hemolytic uremic syndrome (HUS) with possible kidney failure.
A. it only causes occupational illness in people who work with animals.
All species of Staphylococcus: A. lack spores. B. are motile. C. are motile. D. produce coagulase. E. All of the choices are correct.
A. lack spores.
Ureaplasma urealyticum is implicated in which of the following? A. nongonococcal urethritis B. Rocky Mountain Spotted Fever C. periodontal disease D. Q fever E. endemic typhus
A. nongonococcal urethritis
Gingivitis is A. primarily caused by anaerobic oral flora. B. erosion of tooth enamel causing a lesion. C. caused by Streptococcus mutans. D. also called NUG. E. None of the choices are correct.
A. primarily caused by anaerobic oral flora.
This type of anthrax is called "wool-sorter's disease": A. pulmonary. B. gastrointestinal. C. cutaneous. D. All of the choices are correct. E. None of the choices are correct.
A. pulmonary.
Nationwide, over 100,000 patients a year die from septic shock. This is due to A. the presence of lipopolysaccharide in the outer membrane. B. lipoteichoic acid in the cell wall. C. a cytotoxin similar to the diphtheria toxin. D. coagulase. E. a neurotoxin similar to botulin.
A. the presence of lipopolysaccharide in the outer membrane.
Control of rodent populations is important for preventing A. tick-borne relapsing fever. B. ornithosis. C. epidemic typhus. D. Q fever. E. All of the choices are correct.
A. tick-borne relapsing fever.
Rabbits and rodents are the reservoirs of the causative agent of A. tularemia. B. pertussis. C. Legionellosis. D. brucellosis. E. shigellosis.
A. tularemia.
The energy needed for protein synthesis is provided by the hydrolysis of
ATP and GTP.
Which of the following is the initiator codon?
AUG
Which of the following types of experimental evidence suggests that a particular organism thought to be part of the human microbiome is, in fact, just a laboratory contaminant?
Absence of ribosomal RNA evidence in a specific host location where the organism was believed to have colonized.
Which of the following processes can be used to bring nutrients into a cell against a concentration gradient?
Active transport
Which type of membrane transport is most important for nutrient acquisition in nutrient poor environments?
Active transport
Which of the following is not a pyrimidine?
Adenine
Which of the following is not a complementary base pair usually found in DNA molecules?
Adenine-uracil
Which of the following eukaryotes typically have cell walls? (Check all that apply.)
Algae, Fungi
Which of the following can be used to isolate pure cultures of bacteria from mixtures?
All of the choices are corrcet.
Acute respiratory viruses cause ________.
All of the choices are correct.
Animal viruses have been cultivated in
All of the choices are correct.
Archaeal membranes contain which of the following lipids?
All of the choices are correct.
Bacteria within biofilms exchange
All of the choices are correct.
Beta-hemolytic group A streptococci are responsible for _______________.
All of the choices are correct.
Campylobacter jejuni is commonly found in the intestinal tract of ____________.
All of the choices are correct.
Control measures for hepatitis B include
All of the choices are correct.
Diptheria is an acute contagious disease caused by an exotoxin that
All of the choices are correct.
Francisella tularensis is transmitted to humans by
All of the choices are correct.
Gonorrhea, a sexually transmitted disease, is an acute infection of the mucous membranes of the ________.
All of the choices are correct.
In a lichen, the fungal partner
All of the choices are correct.
In mutualism
All of the choices are correct.
In the rumen, the carbohydrate fermentation end products include
All of the choices are correct.
Legionella pneumophila may be found in
All of the choices are correct.
Microdomains in eukaryotic plasma membranes can participate in
All of the choices are correct.
Prevention and control of rabies includes
All of the choices are correct.
Quorum sensing
All of the choices are correct.
Riftia tube worms make a unique kind of hemoglobin to
All of the choices are correct.
Some researchers have suggested that archaeal flagella be renamed as archaella because
All of the choices are correct.
The Archaea generally lack which of the following that are normally found in gram-negative bacteria?
All of the choices are correct.
The antiviral drugs currently approved for use in HIV disease include
All of the choices are correct.
The characteristics of a pathogen that determine its virulence include which of the following?
All of the choices are correct.
The concentration of an antimicrobial drug that is reached in the body will depend on
All of the choices are correct.
The cytoplasmic membrane of bacteria
All of the choices are correct.
The ectosymbionts of ruminant animals are useful to their hosts in which of the following ways?
All of the choices are correct.
The exotoxin produced by Corynebacterium diptheriae
All of the choices are correct.
The final outcome of most host-parasite relationships depends on
All of the choices are correct.
The length of the lag phase of growth can vary depending on
All of the choices are correct.
The lungs are protected from microorganisms by
All of the choices are correct.
The rabies virus is transmitted to humans by
All of the choices are correct.
The type III bacterial protein secretion machinery
All of the choices are correct.
Trachoma is transmitted by __________.
All of the choices are correct.
Treatment of gas gangrene may involve _______.
All of the choices are correct.
Viral envelopes are composed of
All of the choices are correct.
Which of the following affects the size of the clear zone in a disk diffusion test of antimicrobial susceptibility?
All of the choices are correct.
Which of the following are a reason(s) for the decline in cell numbers during the death phase?
All of the choices are correct.
Which of the following are characteristics of hydrogenosomes that distinguish them from mitochondria?
All of the choices are correct.
Which of the following areas of the human body is (are) not normally free of microorganisms?
All of the choices are correct.
Which of the following can be used to cultivate plant viruses?
All of the choices are correct.
Which of the following can be used to estimate the number of microorganisms in a culture?
All of the choices are correct.
Which of the following can stimulate a reactivation of the virus that causes cold sores?
All of the choices are correct.
Which of the following contribute to the environmental resistance of bacterial endospores?
All of the choices are correct.
Which of the following contribute(s) to the differences between the members of the Domain Archaea and the Domain Bacteria?
All of the choices are correct.
Which of the following diseases is (are) caused by prions?
All of the choices are correct.
Which of the following does (do) not always require the presence of living bacteria?
All of the choices are correct.
Which of the following drug(s) is (are) used to treat tuberculosis?
All of the choices are correct.
Which of the following has no effect on the outcome of the host-parasite relationship?
All of the choices are correct.
Which of the following influence(s) the efficiency of an antimicrobial agent?
All of the choices are correct.
Which of the following is (are) true about cephalosporins?
All of the choices are correct.
Which of the following is (are) used by microorganisms to become resistant to a particular drug?
All of the choices are correct.
Which of the following is a characteristic of active transport?
All of the choices are correct.
Which of the following is a desirable general characteristic of antimicrobial drugs?
All of the choices are correct.
Which of the following is a function of pasteurization?
All of the choices are correct.
Which of the following is a function of the mitochondrion?
All of the choices are correct.
Which of the following is a useful mechanism of action for an antimicrobial drug?
All of the choices are correct.
Which of the following is known to activate the genital herpes virus?
All of the choices are correct.
Which of the following is prevented by the D TaP vaccine?
All of the choices are correct.
Which of the following is true about the structure of DNA?
All of the choices are correct.
Which of the following is/are advantages of using bacteriophage to treat human bacterial infections?
All of the choices are correct.
Which of the following is/are true of capsules?
All of the choices are correct.
Which of the following may form one colony?
All of the choices are correct.
Which of the following strategies enable non-acidophilic bacteria to endure lower pH environments?
All of the choices are correct.
Which of the following syndromes may result from infection by an arthropod-borne virus?
All of the choices are correct.
Which of the following effects may be mediated by transposable elements?
All of the choices are correct. (A mutation may result from insertion into a gene. Activation of nearby genes may occur. Genetic deletions may form.)
Which type(s) of mutation might lead to a threonine auxotrophic revertant?
All of the choices are correct. (Base substitution. Missense mutation. Point mutation.)
If you wished to study the SOS response in Escherichia coli, which of the following experimental procedures could be used?
All of the choices are correct. (Expose cells to nonionizing radiation for 20 minutes. Expose cells to ionizing radiation for 10 minutes. Transfer log phase cells from complete medium to thymine minimal medium. Inactivate genes that encode DNA polymerases.)
Which of the following is not a strategy bacteria use to resist the action of antibiotics?
All of the choices are correct. (Modification of the antibiotic by the acetylation or phosphorylation. Cleavage of key structural component of the antibiotic. Altering cell membrane structure to prevent antibiotic influx.)
Which of the following is considered a reverse mutation that will restore the wild type phenotype?
All of the choices are correct. (True reversion back to the wild type base sequence. Mutation to a different base sequence, but one that restores the amino acid sequence in the protein to the wild type sequence. A mutation that restores the function of a protein even though it does not restore the base sequence or the amino acid sequence to the wild type.)
Site-specific recombination systems
All of the choices are correct. (do not depend on extensive nucleotide sequence homology. depend on enzymes that are often specific for sequences within the host. are features of some viruses.)
One possible fate for an exogenote is
All of the choices are correct. (integration into the host chromosome. independent replication and functioning. degradation of nucleotides.)
Insertion sequences are
All of the choices are correct. (normally relatively short (700 to 1,650 bp). capable of transposition. are discrete genetic elements bounded at both ends with inverted repeats.)
SOS repair
All of the choices are correct. (requires RecA protein. is inducible by DNA damage. is error prone, i.e., produces mutations.)
Cells may enter stationary phase because of
All of the choices are correct. (the depletion of an essential nutrient, a lack of available oxygen, and the accumulation of toxic waste products)
During generalized transduction
All of the choices are correct. (the host chromosome is degraded into randomly sized fragments. any DNA fragment of the appropriate size is packaged. any bacterial gene may be transferred to the subsequent host.)
Which of the following is important in the treatment of potential infections by Clostridium tetani?
All of the choices are important in the treatment of potential infections by Clostridium tetani.
Which of the following is considered a cardinal growth temperature?
All of these are considered cardinal growth temperatures.
Which of the following is a reason for the occurrence of a lag phase in a bacterial growth curve?
All of these are potential reasons.
Which statement best describes the mechanism(s) of posttranslational regulation of gene expression?
Allosteric regulation following transcription of mRNA occurs in many biosynthetic pathways.
Which of the following is not present in DNA?
Alpha carbon
You and a classmate are discussing early experiments in genetics, and you state that Avery, MacLeod, and McCarty provided the first evidence that DNA carries genetic information. Your classmate argues that Griffith was the first to demonstrate this. Which statement best defends your argument?
Although Griffith first demonstrated transformation, Avery, MacLeod, and McCarty provided evidence that DNA rather than protein or RNA was the first transforming agent.
__________ and _________ can be used to prevent influenza A infections, reducing the incidence of influenza by 50 to 70% in an exposed population.
Amantadine, rimantadine
If you were to design a novel hydrophobic protein, which type of monomers would be most essential to incorporate in the molecule in order to achieve the desired result?
Amino acids with nonpolar side chains
_____________ from Streptomyces spp. binds to the sterols in fungal membranes, disrupting membrane permeability and causing leakage of cell constituents.
Amphotericin B
You are working with a newly discovered microorganism that has flagella that are solid, 10 nm in diameter, and composed of more than one type of flagellin subunit. Based on the type of flagella, which type of organism is this?
Archaea
Microorganisms in the human colon are more often being described as mutualistic with human hosts rather than commensalistic. Why has this change in the definition of a symbiotic relationship occurred?
As we learn more about the ecology of the human microbiome, we recognize our dependence on these organisms for immunity, vitamin production, and other essential processes.
Which of the following is not a regulatory mechanism used to control the lactose operon in Escherichia coli?
Attenuation
___________ is used to control transcription of some anabolic pathways involved in amino acid biosynthesis.
Attenuation
Which of the following is MOST effective against resistant endospores?
Autoclaving
_______ are strains that are unable to grow on a minimal medium that supports growth of the wild type of strain, but are able to grow on the minimal medium if one or more nutritional supplements are added.
Auxotrophs
Newborn infants can be infected with Group _______ streptococcus during birth.
B
Which of the following is normal oral and nasopharyngeal flora but is involved in infective endocarditis in adults who have underlying congenital or rheumatic heart disease? A. Haemophilus influenzae B. Haemophilus aphrophilus C. Haemophilus aegyptius D. Haemophilus ducreyi E. All of the choices are correct.
B. Haemophilus aphrophilus
Which of the following antibiotics specifically disrupt protein synthesis of streptococci? A. Beta-lactams B. Macrolides C. Cephalosporins D. Ansamycin E. Aminoglycosides
B. Macrolides
Causes a non-communicable pulmonary infection that resembles tuberculosis: A. Mycobacterium avium complex (MAC) B. Mycobacterium kansasii C. Mycobacterium scrofulaceum D. Mycobacterium fortuitum complex E. Mycobacterium marinum.
B. Mycobacterium kansasii
During which stage of syphilis does fever, lymphadenopathy, and a red to brown rash occur? A. Primary B. Secondary C. Tertiary D. Latent E. All of the choices are correct
B. Secondary
Sue brought her daughter Amy to the pediatrician complaining of a sore throat. The physician examines Amy and observes that her throat is bright red and there are white pus-filled nodules on her tonsils. Which of the following conclusions should be made? A. She has a strep throat and should begin antibiotics. B. She should have a rapid strep test performed before a diagnosis is made. C. She should go home and rest because most sore throats are viral in origin. D. She should go home and come back in two days for a strep test since it may take that long to show up. E. She has a staphylococcal sore throat and should begin antibiotics immediately.
B. She should have a rapid strep test performed before a diagnosis is made.
Which of the following is not correct concerning the plague? A. Mice, voles, and other rodents are primary long-term reservoirs. B. Strains of the plague bacillus are less virulent today as they were in the Middle Ages. C. It is transmitted by flea vectors. D. Less than 10 cases per year occur in the US. E. The etiological agent is Yersinia pestis.
B. Strains of the plague bacillus are less virulent today as they were in the Middle Ages.
Which of the following is not correct concerning Legionnaires disease? A. L. pneumophila lives in close associations with free-living amoebas. B. The disease is communicable from person to person. C. Symptoms include cough, diarrhea, and abdominal pain. D. It is more common in males over 50 years of age. E. Cases have been traced to the fallout from the Mount Saint Helen's volcano.
B. The disease is communicable from person to person.
An organism found in coastal waters that causes a food infection and gastroenteritis due to a variety of contaminated raw and undercooked seafood is A. Chlamydia trachomatis. B. Vibrio parahaemolyticus. C. Vibrio cholerae. D. Campylobacter jejuni. E. Helicobacter pylori.
B. Vibrio parahaemolyticus.
Characteristics of Bacillus anthracis include all the following, except: A. capsule and exotoxins are virulence factors. B. anaerobic. C. reservoir includes infected grazing animals and contaminated soil. D. gram positive bacillus. E. spore former
B. anaerobic.
Symptoms of Toxic Shock Syndrome include all the following, except: A. fever and muscle pain. B. appearance of flesh being "eaten" down to the muscle. C. nausea, vomiting, diarrhea. D. sunburn-like rash. E. kidney and liver failure.
B. appearance of flesh being "eaten" down to the muscle.
Meningococcemia is: A. common during gonorrhea. B. associated with vascular hemorrhage and petechiae. C. frequently seen in elderly. D. caused by a gram positive diplococcus. E. All of the choices are correct.
B. associated with vascular hemorrhage and petechiae.
Pertussis has the following characteristics, except: A. pathogen has virulence factors to destroy the action of respiratory cilia. B. catarrhal stage has persistent, hacking coughs with "whoops". C. early stage resembles a cold with nasal discharge and sneezing. D. DTaP immunization will prevent it. E. transmission is by respiratory droplets.
B. catarrhal stage has persistent, hacking coughs with "whoops".
Whooping cough is transmitted via respiratory droplets. The___stage lasts 1-2 weeks, while the second stage________is when a person has severe coughing. A. primary, secondary B. catarrhal, paroxysmal C. incubation, convalescent D. Low T-cell, High macrophage
B. catarrhal, paroxysmal
The enzyme that coagulates plasma is: A. catalase. B. coagulase. C. hyaluronidase. D. staphylokinase. E. Dnase.
B. coagulase.
Mycobacterium tuberculosis: A. produces several virulence factor enzymes and an exotoxin. B. has a cord factor that can prevent destruction by lysosomes and macrophages. C. is a spore former. D. has a capsule. E. lives in the soil.
B. has a cord factor that can prevent destruction by lysosomes and macrophages.
Which of the following is not caused by Haemophilus influenzae? A. bacterial meningitis B. influenza (flu) C. otitis media D. bronchitis E. epiglottitis
B. influenza (flu)
Ornithosis A. is caused by Chlamydia pneumoniae. B. is a zoonosis of certain types of birds. C. is a mild, upper respiratory tract illness. D. has humans as a reservoir for the pathogen. E. All of the choices are correct.
B. is a zoonosis of certain types of birds.
All of the following are associated with subacute endocarditis, except: A. it occurs in patients that have prior heart damage. B. it is caused by immune system autoantibodies that attack heart and valve tissue. C. oral bacteria get introduced by dental procedures to the blood. D. bacteria colonize previously damaged heart tissue resulting in vegetation. E. signs and symptoms include fever, heart murmur, and possible emboli.
B. it is caused by immune system autoantibodies that attack heart and valve tissue.
Salmonella are A. coliforms. B. motile. C. gram positive rods. D. lactose fermenters. E. All of the choices are correct.
B. motile.
Treponema vincentii, Bacteroides forsythus, and fusobacteria synergistically are involved in which infection? A. gingivitis B. necrotizing ulcerative gingivitis (NUG) C. ornithosis D. yaws
B. necrotizing ulcerative gingivitis (NUG)
All of the following pertain to infant botulism, except: A. symptoms include "floppy baby" appearance. B. neurotoxin is not involved in the disease process. C. ingested spores can germinate in the immature intestines of the neonate. D. symptoms include flaccid paralysis and respiratory complications. E. it is the most common type of botulism in the United States.
B. neurotoxin is not involved in the disease process.
All of the following pertain to Listeria monocytogenes, except: A. gram positive B. sporeformer C. contaminant of dairy products, meats, poultry D. causes foodborne listeriosis E. bacterial cells multiply within the cytoplasm of a host cell
B. sporeformer
The RPR, VDRL, MHA-TP, FTA-ABS, and TPI tests are used to diagnose A. chlamydiosis. B. syphilis. C. lyme disease. D. Rocky Mountain spotted fever. E. Q fever.
B. syphilis.
All of the following are correct about Staphylococcus aureus, except: A. it is the coagulase-positive species. B. the body's most powerful defense against it lies in the T-cell response. C. carriers may be treated with antibiotics to clear them of the bacteria. D. most strains are resistant to penicillin and ampicillin. E. it causes furuncles, carbuncles, and abscesses.
B. the body's most powerful defense against it lies in the T-cell response.
Which of the following is not true about leprosy? A. it is caused by Hansen's bacillus in honor of its discoverer B. the leprosy bacillus is highly virulent C. armadillos harbor a genetically identical M. leprae D. early signs appear as small, spotty lesions colored differently than the surrounding skin E. the number of new cases in the U.S. each year is about 100 to 200
B. the leprosy bacillus is highly virulent
Which was common to experiments done by Avery and colleagues as well as Hershey and Chase?
Bacterial cells
Which of the following inhibits bacterial growth but does not kill bacteria?
Bacteriostatic agent
Which of the following mutagens is most different than the others in terms of its effects on DNA?
Base analogue
Which of the following is a Gram-negative bacterium that acts as a predator on other Gram-negative bacteria, and might be used to control populations of Gram-negative human pathogens in locations such as poultry farms?
Bdellovibrio
__________ is a predator that bores a hole through the outer membrane of its gram-negative prey and then reproduces in the periplasm.
Bdellovibrio
A bacterial genus that is found in large numbers in the intestinal tract of breast-fed infants is
Bifidobacteria.
Which of the following characterize biofilms the form within the body?
Biofilms help microorganisms adhere to human tissue. Biofilms protect microbes from the body's defenses. Biofilms protect microorganisms from antibiotics.
The causative agent of whooping cough is ___________.
Bordetella pertussis
Which types of eukaryotic cells have cell walls composed of cellulose?
Both algae and plants.
How are termite-related protists and aphid-related proteobacteria similar?
Both are mutualists with their respective hosts.
A microbiologist is working with two genera of bacteria, A and B, to determine if cells are competent. Strains are grown under optimal conditions, and DNA fragments that carry the gene for green fluorescent protein is added to each culture at 20-minute intervals. Samples from each treatment are plated to nutrient agar and incubated, after which the plates are examined under an ultraviolet lamp. The microbiologist observes that all plates of bacteria B contain colonies that are fluorescent, while for bacteria A only the plates from stationary phase demonstrate fluorescent colonies. What can be concluded from these results?
Both bacteria A and B cells are competent.
Which of the following is common to both factor-dependent and factor-independent transcription termination?
Both types of termination occur following a pause by the polymerase.
Which of the following would you not find in the nasopharynx?
Branhamella catarrhalis
Which of the following is not part of the lichen association?
Brown algae
Which of the following is a facultative, rather than obligate, intracellular pathogen?
Brucella
Which virion release process is most often used by enveloped viruses?
Budding
Which of the following statements best explains why microbial geneticists initially focused on regulation of gene expression at the transcriptional, rather than translational, level?
By regulating the first step of protein synthesis, cells conserve the greatest amount of energy.
The causative agent of Lyme disease is A. Ixodes scapularis. B. Borrelia hermsii. C. Borrelia burgdorferi. D. Ixodes pacificus. E. Leptospira interrogans.
C. Borrelia burgdorferi.
Which of the following diseases could be prevented with proper sewage disposal and water purification? A. Vibrio parahaemolyticus gastroenteritis B. Vibrio vulnificus gastroenteritis C. Cholera D. Lyme disease E. Leptospirosis
C. Cholera
According to CDC data, who is more likely to acquire a rickettsial disease? A. Tom who traveled to Arizona for the summer B. Sally who went to the beach at Big Sur, CA C. Mike who visited his aunt in Sub-Saharan Africa D. Phil who stayed home and mowed his lawn E. Harry who works in a pet store and hates fleas and ticks
C. Mike who visited his aunt in Sub-Saharan Africa
If left untreated, an infection with ___ can lead to pelvic inflammatory disease and infertility. A. Streptococcus pneumoniae B. N. meningitidis C. N. gonorrhoeae D. Streptotoccus pyogenes E. Staphylococcus aureus
C. N. gonorrhoeae
The gram-negative bacillus associated with abscesses from dog and cat bites or scratches is A. Salmonella typhimurium. B. Yersinia enterocolitica. C. Pasteurella multocida. D. Brucella suis. E. Francisella tularensis.
C. Pasteurella multocida.
Although this bacteria is typically found in soil and water, burn wound patients are susceptible to ___infection. A. Yersinia pestis B. Bordetella pertussis C. Pseudomonas D. E. coli 0157:H7
C. Pseudomonas
All of the following are coliforms that cause opportunistic and nosocomial infections, except: A. Enterobacter. B. Citrobacter. C. Shigella. D. Klebsiella. E. Serratia
C. Shigella.
Which organism is associated with commonly causing urinary tract infections in sexually active young adult and adolescent females? A. Staphylococcus aureus B. Staphylococcus epidermidis C. Staphylococcus saprophyticus D. Streptococcus pyogenes E. Streptococcus agalactiae
C. Staphylococcus saprophyticus
Which chemical, produced by S. aureus, digests blood clots? A. Coagulase B. Penicillinase C. Staphylokinase D. Hyaluronidase E. Toxic shock syndrome toxin
C. Staphylokinase
Which of the following distinguishes syphilis from yaws? A. Syphilis is caused by a spirochete. B. Syphilis has a primary, secondary, and tertiary stages. C. Syphilis is sexually transmitted. D. Syphilis is treated with antibiotics. E. Syphilis is a slow and progressive disease.
C. Syphilis is sexually transmitted.
Permanent cardiovascular and neurological damage is seen in which stage of syphilis? A. Primary B. Secondary C. Tertiary D. Latent E. All of the choices are correct.
C. Tertiary
"Rice water stools" are associated with disease caused by this organism: A. Vibrio vulnificus B. Vibrio parahaemolyticus C. Vibrio cholerae D. Campylobacter jejuni E. Helicobacter pylori
C. Vibrio cholerae
Streptococcus pneumoniae is: A. called the meningococcus. B. in the viridans group. C. a gram positive diplococcus with a capsule. D. a pathogen with endotoxin. E. All of the choices are correct.
C. a gram positive diplococcus with a capsule.
Erysipeloid is transmitted by: A. inhalation of spores from hides and wool of animals. B. ingestion of improperly cooked hot dogs. C. an abrasion on skin coming in contact with infected swine or other animals. D. contaminated soil entering deep puncture wounds. E. respiratory secretions.
C. an abrasion on skin coming in contact with infected swine or other animals.
The most common site where carriers of Staphylococcus aureus carry this pathogen is: A. all over the skin. B. under the fingernails. C. anterior nares (nostrils). D. mouth. E. intestines.
C. anterior nares (nostrils).
Actinomyces israelii: A. can be transmitted by respiratory droplets. B. can cause pneumonia with symptoms similar to tuberculosis. C. are filamentous rods that grow in clusters called sulfur granules in infected tissue. D. lives in the soil. E. causes most cases in the immunocompromised.
C. are filamentous rods that grow in clusters called sulfur granules in infected tissue.
Necrotizing fasciitis is: A. also called impetigo. B. possibly caused by antibodies to Group A streptococci that cross-react with body tissues. C. associated with strains of Streptococcus pyogenes producing destructive enzymes and toxins. D. typically a sequelae of streptococcal pharyngitis. E. not treatable with antimicrobic drugs.
C. associated with strains of Streptococcus pyogenes producing destructive enzymes and toxins.
Generally, what must healthy adults consume in order to contract botulism? A. spores of C. botulinum B. vegetative cells of C. botulinum C. botulin toxin on contaminated food D. botulin toxoid on contaminated food E. botulin antitoxin on contaminated food
C. botulin toxin on contaminated food
The foodborne disease that involves neurotoxin is: A. gastrointestinal anthrax. B. Bacillus cereus intoxication. C. botulism. D. Clostridium perfringens gastroenteritis. E. All of the choices are correct.
C. botulism.
Staphylococci can be differentiated from streptococci by the: A. Gram stain. B. coagulase test. C. catalase test. D. fermentation of mannitol. E. None of the choices are correct.
C. catalase test.
Leprosy is a disease: A. of lung tissue. B. that has been eradicated around the world. C. caused by a pathogen that cannot be cultured in the lab. D. can be diagnosed by the Mantoux test. E. caused by a sporeforming, gram-positive bacillus.
C. caused by a pathogen that cannot be cultured in the lab.
Which form of anthrax involves a black eschar on the skin? A. pulmonary B. gastrointestinal C. cutaneous D. All of the choices are correct. E. None of the choices are correct.
C. cutaneous
Pseudomonas aeruginosa causes all the following, except A. severe nosocomial infection in burn patients. B. skin rashes from contaminated hot tubs and bath sponges. C. diarrheal illness. D. external ear infection. E. serious infection in lung tissue of cystic fibrosis patients.
C. diarrheal illness.
The major virulence factor of Corynebacterium diphtheriae that causes serious systemic effects is: A. capsule. B. metachromatic granules. C. exotoxin. D. endospores. E. endotoxin.
C. exotoxin.
Rocky Mountain spotted fever A. is seen in highest numbers along the west coast. B. is transmitted by Ixodes ticks. C. has symptoms that include fever, headache, and rash. D. never has severe complications. E. All of the choices are correct.
C. has symptoms that include fever, headache, and rash.
The secondary stage of syphilis A. is when the patient is no longer infectious to others. B. occurs within 10 days of the primary stage. C. is a time when the pathogen enters and multiplies in the blood. D. has no symptoms. E. is when gummas develop in tissues.
C. is a time when the pathogen enters and multiplies in the blood.
Which is incorrect about shigellosis? A. outbreaks have occurred in day care centers B. it is watery diarrhea with bloody, mucoid stools, and abdominal cramps C. it frequently involves septicemia D. human carriers cause fecal transmission E. it is also called bacillary dysentery
C. it frequently involves septicemia
All of the following are correct about Streptococcus pyogenes, except: A. humans are the only significant reservoir. B. some of the streptococcal toxins act as superantigens. C. most strains do not have a capsule. D. it can cause impetigo and erysipelas. E. infection is generally through direct contact.
C. most strains do not have a capsule.
The M protein of Streptococcus pyogenes: A. is the basis for the organism belonging to Lancefield group A. B. gives rise to a zone of b hemolysis on blood agar. C. protects against phagocytosis and enhances adherence. D. is also called streptokinase. E. protects against lysozyme damage.
C. protects against phagocytosis and enhances adherence.
Infections caused by Staphylococcus aureus include all of the following, except: A. folliculitis. B. furuncles and carbuncles. C. sore throat. D. osteomyelitis. E. pneumonia.
C. sore throat.
Which is not a characteristic of Nocardia? A. it can be transmitted by respiratory droplets. B. it can cause pneumonia with symptoms similar to tuberculosis. C. they are filamentous rods that grow in clusters called sulfur granules in infected tissue. D. it lives in the soil. E. it causes most cases in the immunocompromised.
C. they are filamentous rods that grow in clusters called sulfur granules in infected tissue.
The buildup of mucus and blockage of airways in pertussis is due to A. endotoxin B. lipopolysaccharide. C. toxins that destroy the ciliated cells of the respiratory tract. D. Pseudomonas aeruginosa. E. the presence of a capsule.
C. toxins that destroy the ciliated cells of the respiratory tract.
Infected animals shed Leptospira interrogans in their A. feces. B. blood. C. urine. D. respiratory secretions. E. saliva
C. urine.
The AIDS virus becomes established in cells bearing the ________ receptor.
CD4
If the predominating microbiota of a particular human body site included Lactobacillus, Gardnerella, and Bacteroides, it would not be unusual to isolate which of the following as well?
Candida
Which of the following is not involved in the transmission of salmonellosis?
Canned vegetables
__________ are hollow tube-like structures that hold some archaeal daughter cells together after cell division while __________ are grappling hook-like structures that appear to attach archaeal cells to surfaces.
Cannulae; hami
Which of the following structures is NOT found in an endospore?
Capsule
Which of the following do airborne microorganisms and microorganisms on light-exposed surfaces use to protect themselves from photooxidation?
Carotenoid pigments
It has been observed that when the sugar source changes in a growth medium, the growth rate of yeast vary widely in response. Some strains of yeast are slow to induce catabolic operons while other strains quickly synthesize proteins to process the new sugar. What might be one explanation for this difference in the growth rate of the strains?
Catabolic repression strategies of operons for using different sugars may vary among strains, thereby favoring initiation of transcription in one strain over another depending on the sugar.
Which of the following is not a regulatory mechanism used to control the tryptophan operon in Escherichia coli?
Catabolite repression
In catabolite repression systems of some Gram-positive bacteria, such as Bacillus subtilis, transcription of catabolic operons is regulated by CcpaA (catabolite control protein A) rather than cAMP. Propose a hypothesis to explain the preferential use of glucose in the presence of a second sugar such as sucrose by Bacillus subtilis.
CcpaA acts as a repressor of sucrose operon genes in Bacillus subtilis when both sugars are present.
_________ enzymes catalyze the hydrolysis of beta (1-4) linkages between successive D-glucose residues of cellulose.
Cellulase
Which of the following is not associated with genital herpes?
Cervical cancer
Which modification of the terminator region of a gene would specifically prevent rho-independent termination?
Change in the adenine-rich sequence of nucleotides of the terminator region.
Which of the following events occurs initially when Escherichia coli cells are in a gradient of chemorepellent?
CheA autophosphorylates
Which of the following would be most effective and practical for routine home disinfection of a kitchen sponge between uses?
Chlorine bleach
Which of the following parts of the Golgi complex receives material from the ER?
Cis face
The pathogen most frequently involved in causing clostridial myonecrosis is
Clostridium perfringens
Which of the following is not considered a macronutrient?
Cobalt (Co)
The treatment for pneumonia caused by Pneumocystis jiroveci in AIDS patients is
Combination of trimethoprim and sulfisoxazole
Biofilm formation by Pseudomonas bacteria on the surface of a natural loofa sponge kept in the shower is an example of which type of relationship?
Commensalism
Which of the following is not a category of symbiosis?
Communalism
_________ arises when different microbes within a population or community try to acquire the same resource.
Competition
You would like to culture a bacterium that is growing in the lung of a human patient with pneumonia. Which media would be of most use in culturing this organism?
Complex medium supplemented with whole blood
Predict the outcome of an F+ and F- mating if the F+ cell lacked a functional tra operon.
Conjugation would not occur because there would be no contact between the F+ and F- cells.
Which of the following is the typical mode of transmission for hepatitis C?
Contaminated blood and blood products
____________ is a beneficial relationship similar to mutualism, in which the relationship is not obligatory.
Cooperation
__________ activate repressor proteins, thereby, decreasing the synthesis of certain enzymes.
Corerepressors
Where is the glycolysis pathway located in a cell?
Cytoplasm
Which bacteria could be responsible for hemolytic uremic syndrome (HUS)? A. Eterotoxigeic strains of E. coli B. Salmonella C. Shigella dysenteriae D. E. coli 0157:H7 E. Eteroinvasive E. coli
D. E. coli 0157:H7
Which of the following is an agent of the sexually transmitted disease chancroid? A. Haemophilus aegyptius B. Haemophilus influenzae C. Haemophilus parainfluenzae D. Haemophilus ducreyi E. Haemophilus aphrophilus
D. Haemophilus ducreyi
The vaccine for immunity to Haemophilus influenzae serotype b is A. DtaP. B. Pneumovax. C. MMR. D. Hib. E. None of the choices are correct.
D. Hib.
Which chemical produced by S. aureus is also known as "spreading factor"? A. Coagulase B. Penicillinase C. Hemolysin D. Hyaluronidase E. Toxic shock syndrome toxin
D. Hyaluronidase
Which is incorrect about Staphylococcus aureus food intoxication? A. Food becomes contaminated by a human carrier. B. Common associated foods include custards, ham, cream pastries, processed meats. C. After contamination, food must be left unrefrigerated for a few hours. D. Ingestion of the pathogen allows it to multiply and damage the GI tract lining. E. Symptoms come on quickly, and include nausea, vomiting, diarrhea.
D. Ingestion of the pathogen allows it to multiply and damage the GI tract lining.
Erythema migrans, a bull's-eye rash, at the portal of entry is associated with A. syphilis. B. Rocky Mountain spotted fever. C. relapsing fever. D. Lyme disease. E. leptospirosis.
D. Lyme disease.
A client has a serious case of lung infection. A cerebrospinal fluid sample was taken. The lab tech said they isolated a bacterium that did not have any peptidoglycan. You hypothesize that the identity of this microbe could possibly be __. A. Mycobacterium tuberculosis B. Borrelia burgdorfer C. Streptococcus pneumoniae D. Mycoplasma pnmoniae
D. Mycoplasma pnmoniae
The instillation of antibiotics in newborn's eyes will prevent ophthalmia neonatorum in newborns. This disease is caused by: A. Neisseria meningitidis. B. Staphylococcus aureus. C. Streptococcus pyogenes. D. Neisseria gonorrhoeae. E. Branhamella (Moraxella) catarrhalis.
D. Neisseria gonorrhoeae.
Which of the following species was once considered so benign that microbiologists used it to trace movements of air currents in hospitals and over cities? A. Morganella B. Providenci C. Citrobacter D. Serratia E. Legionella
D. Serratia
Which of the following is NOT characteristic of Actinomyces israelii? A. Important for compost production B. Found in soil C. Rods with colonies displaying hyphael growth D. Strict aerobe E. Non-endospore former
D. Strict aerobe
What is incorrect about pertussis? A. A virulence factor of B. pertussis is toxins that destroy cilia cells is produced. B. The source of infection is direct contact with inhaled droplets. C. The paroxysmal stage is characterized by persistent coughing. D. The number of cases is steadily decreasing since 1976. E. It can cause severe, life-threatening complications in babies.
D. The number of cases is steadily decreasing since 1976.
Hutchinson's teeth are A. a symptom of untreated Lyme disease. B. a symptom of untreated periodontal disease. C. a symptom of ANUG. D. a symptom of congenital syphilis. E. a symptom of congenital Chlamydia trachomatis.
D. a symptom of congenital syphilis.
People at greatest risk for pneumococcal infections include all the following, except: A. elderly. B. those with underlying lung disease and viral infections. C. patients without a spleen. D. adolescents and young adults. E. young infants.
D. adolescents and young adults.
Pasteurization of milk helps to prevent A. tularemia. B. pertussis. C. Legionellosis. D. brucellosis. E. shigellosis
D. brucellosis.
Which is not correct about Bacillus cereus? A. present in soil B. produce enterotoxins C. causes foodborne intoxication D. causes a zoonosis E. associated with cooked rice, potato, and meat dishes that are stored at room temperature
D. causes a zoonosis
Botulism will always be a threat for people who: A. are meat eaters. B. are vegetarians. C. have a weakened immune system. D. consume home-preserved foods. E. eat often in restaurants.
D. consume home-preserved foods.
The chancre of syphilis A. occurs due to small hemorrhaging of capillaries. B. is very painful. C. occurs during the tertiary stage. D. develops into a lesion with firm margins and an ulcerated central crater. E. All of the choices are correct.
D. develops into a lesion with firm margins and an ulcerated central crater.
The following are characteristics of Chlamydias except: A. gram negative B. obligate parasites that need host cells for growth C. elementary bodies are the infectious form D. elementary bodies lack enzyme systems for making ATP E. reticulate bodies differentiate into elementary bodies
D. elementary bodies lack enzyme systems for making ATP
The virulence of Vibrio cholerae is due to its A. capsule. B. neurotoxin. C. invasive enzymes. D. enterotoxin
D. enterotoxin
The toxin of Staphylococcus aureus strains that causes blisters and desquamation of skin in scalded skin syndrome is: A. enterotoxin. B. hemolysin. C. toxic shock syndrome toxin. D. exfoliative toxin. E. erythrogenic toxin.
D. exfoliative toxin.
Characteristics of all the members of the family Enterobacteriaceae include A. ferment lactose. B. are normal flora of human intestines. C. produce enterotoxins. D. ferment glucose. E. All of the choices are correct.
D. ferment glucose.
Shigella species have the following characteristics, except: A. not motile B. release endotoxin C. belong to Enterobacteriaceae D. infect the small intestine E. produce enterotoxin
D. infect the small intestine
Streptococcal pharyngitis involves all the following, except: A. a purulent exudate over the tonsils. B. can lead to scarlet fever if it is an erythrogenic toxin-producing strain. C. can lead to serious sequelae. D. is usually caused by the viridans streptococci. E. causes redness, difficulty in swallowing, and fever.
D. is usually caused by the viridans streptococci.
Yersinia pestis A. was virulent in the Middle Ages but is no longer virulent. B. has humans as an endemic reservoir. C. does not respond to antimicrobic drugs. D. is usually transmitted by a flea vector. E. All of the choices are correct.
D. is usually transmitted by a flea vector
Which of the following pertains to diphtheria? A. it results in meningitis. B. symptoms include vomiting and diarrhea. C. it can be transmitted from mother's birth canal to neonate. D. it is prevented by the DTaP immunization. E. All of the choices are correct.
D. it is prevented by the DTaP immunization.
For which of the following diseases does the "feather test" provide evidence of early infection? A. tuberculosis B. botulism C. tetanus D. leprosy E. anthrax
D. leprosy
All of the following can positively influence the structure of tooth enamel except A. fluoride. B. lysozyme in saliva. C. antibodies in saliva. D. refined sugar. E. genetics
D. refined sugar.
Treponema, Borrelia, and Leptospira are all A. obligate parasites requiring host cells. B. curved rods. C. transmitted by arthropod vectors. D. spirochetes. E. bacteria without cell walls.
D. spirochetes.
What is the usual cause of pseudomembranous colitis? A. improperly home-preserved foods containing botulin toxin B. eating unpasteurized dairy containing Listeria monocytogenes C. handling infected animals contaminated with E. rhusiopathiae D. therapy with broad-spectrum antibiotics leading to superinfection by C. difficile E. living in close contact with someone infected with C. perfringens
D. therapy with broad-spectrum antibiotics leading to superinfection by C. difficile
Long-term sequelae of Group A streptococcal infections include all the following, except: A. risk decreased with prompt treatment of skin infections and pharyngitis. B. development of rheumatic fever. C. appearance of sequelae within a few weeks after an initial infection. D. transmission of sequelae via respiratory secretions from a patient with streptococcal sore throat. E. development of acute glomerulonephritis.
D. transmission of sequelae via respiratory secretions from a patient with streptococcal sore throat.
Mild, uncomplicated cases of pseudomembranous colitis may be treated by: A. debridement. B. wound cleansing. C. vancomycin for several weeks. D. withdrawal of antibiotics and replacement of lost fluids and electrolytes. E. All of the choices are correct.
D. withdrawal of antibiotics and replacement of lost fluids and electrolytes.
Which enzyme is a topoisomerase?
DNA gyrase
Repair of an apurinic or apyrimidinic site in DNA by AP endonuclease must be completed by the action of
DNA polymerase I.
Hershey and Chase demonstrated that when the bacteriophage T2 infected its host cell, the _________ is injected into the host but the __________ remained outside.
DNA; protein
A researcher is attempting to determine the prevalence of asymptomatic human infection with West Nile virus in New York City. Which of the following would be most useful?
Detection of IgG against WNV
A public health microbiologist plans to screen a particular bacterial species that was isolated from several patients in an intensive care unit to detect if any of the cells are penicillin-resistant mutants. What is the first step in conducting this experiment?
Determine whether or not wild type cells of the same bacterial species are susceptible to penicillin.
A researcher proposes that the relationship between a particular bacterial species that produces a fat-soluble vitamin is mutualistic with its insect host. Which of the following procedures would best test the researcher's hypothesis?
Determine which antibiotic kills the bacteria without harming the host, then administer this antibiotic to the insect and compare its growth with and without the vitamin.
A scientist wishes to develop an antimicrobial agent that specifically targets replication elongation in Escherichia coli without interfering with proteins that catalyze other replication processes. Which of the following experimental designs is most appropriate for the scientist to explore?
Develop a molecule that interferes with the DNA-binding ability of DNA polymerase III core enzyme.
Endospores are resistant to most environmental stressors because they have _________ complexed with calcium ions which stabilize DNA.
Dipicolinic acid
Which of the following is likely to have the most toxic side effects to humans?
Disrupters of cell membrane structure
Choose the correct order of proteins that function in the initiation, elongation, and termination stages of DNA replication.
DnaA, DNA polymerase III, DNA polymerase I, DNA ligase
Which is the most common type of virulence gene transferred between fecal bacteria? A. toxin production B. capsules C. fimbriae D. hemolysins E. All of the above
E. All of the above
Which of the following may be recommended for treating gangrene? A. debridement of the wound B. hyperbaric chamber C. amputation of affected limb D. rigorous cleansing of deep wounds E. All of the choices are correct
E. All of the choices are correct
A diagnosis of tuberculosis involves: A. chest X-ray. B. acid fast stain of sputum. C. sputum culture. D. tuberculin skin test. E. All of the choices are correct.
E. All of the choices are correct.
Anthrax is: A. a zoonosis. B. transmitted by contact, inhalation, and ingestion. C. a disease that, in humans, can cause a rapidly fatal toxemia and septicemia. D. only seen sporadically in the United States. E. All of the choices are correct.
E. All of the choices are correct.
Brucellosis is A. a zoonosis. B. seen in the patient as a fluctuating fever, with headache, muscle pain, and weakness. C. associated with pathogen in the blood. D. an occupational illness of people that work with animals. E. All of the choices are correct.
E. All of the choices are correct.
Characteristics of chancroid include: A. sexually transmitted B. occurs mostly in the tropics and subtropics C. lesion develops at portal of entry D. bubo like swelling of the lymph nodes E. All of the choices are correct.
E. All of the choices are correct.
Characteristics of rickettsias include A. obligate parasites requiring host cells for growth. B. arthropods serve as life cycle hosts and vectors. C. gram negative coccobacilli. D. host cells are required for ATP metabolism. E. All of the choices are correct.
E. All of the choices are correct.
Chlamydia trachomatis causes A. nongonococcal urethritis (NGU) in males. B. cervicitis in females. C. congenital and adult inclusion conjunctivitis. D. ocular trachoma. E. All of the choices are correct.
E. All of the choices are correct.
Cholera symptoms are A. copious watery diarrhea. B. loss of blood volume. C. acidosis, sunken eyes, thirst. D. hypotension, tachycardia, shock. E. All of the choices are correct.
E. All of the choices are correct.
Disease/s caused by Streptococcus pneumoniae include: A. otitis media. B. meningitis. C. lobar pneumonia. D. bronchial pneumonia. E. All of the choices are correct.
E. All of the choices are correct.
Neisseria gonorrhoeae is: A. the cause of ophthalmia neonatorum. B. the cause of gonorrhea. C. called the gonococcus. D. virulent due to fimbriae and a protease that inactivates IgA. E. All of the choices are correct.
E. All of the choices are correct.
Oral flora bacteria on the tooth surface A. develop a biofilm. B. use fimbriae and slime layers to adhere. C. include streptococci that metabolize sucrose, produce sticky glucans, and form plaque. D. lactobacilli and streptococci ferment carbohydrates and produce acids that cause caries. E. All of the choices are correct.
E. All of the choices are correct.
Plague includes: A. septicemic form - called Black Death. B. bubonic form - buboes develop. C. pneumonic form - sputum highly contagious. D. disease control - control of rodent population. E. All of the choices are correct.
E. All of the choices are correct.
Pseudomonas aeruginosa is A. found in soil and water. B. an opportunist that produces manydiverse enzymes C. highly chemical resistant. D. motile. E. All of the choices are correct.
E. All of the choices are correct.
Relapsing fever involves A. soft-bodied ticks transmitting Borrelia hermsii. B. initial symptoms of fever, headache, fatigue. C. campers and forestry personnel. D. human body louse transmitting Borrelia recurrentis. E. All of the choices are correct.
E. All of the choices are correct.
Salmonella typhi A. multiplies within phagocytes. B. is not a coliform. C. can be treated with antimicrobics. D. causes invasive infection of the small intestine. E. All of the choices are correct.
E. All of the choices are correct.
Salmonelloses are A. not caused by Salmonella typhi. B. associated with undercooked poultry and eggs, and reptile and rodent feces. C. gastroenteritis with vomiting and diarrhea. D. enteric fevers that often include septicemia. E. All of the choices are correct.
E. All of the choices are correct.
Scarlet fever involves: A. high fever. B. bright red rash on face, trunk, inner arms and legs, and tongue. C. eventual desquamation of epidermis. D. septicemia as a complication. E. All of the choices are correct.
E. All of the choices are correct.
The viridans streptococci are: A. not entirely groupable by Lancefield serology. B. the most numerous residents of the oral cavity. C. opportunists that can cause subacute endocarditis. D. introduced to deeper body tissues by dental or surgical procedures. E. All of the choices are correct.
E. All of the choices are correct.
Treatment and control of anthrax includes: A. use of antimicrobics, such as ciprofloxacin for active cases. B. vaccination of livestock. C. toxoid for military and those with occupational exposure. D. proper disposal of animals that have died from anthrax. E. All of the choices are correct.
E. All of the choices are correct.
Tuberculin skin testing: A. injects PPD intradermally. B. uses a purified protein filtrate of Mycobacterium tuberculosis. C. will be positive if person has had previous exposure. D. will be positive in active TB. E. All of the choices are correct.
E. All of the choices are correct.
Which of the following are symptoms of septic shock? A. Tachycardia B. Reduced blood flow to vital organs C. Respiratory failure D. Weak pulse E. All of the choices are correct.
E. All of the choices are correct.
After being bitten by a tick on a hiking trip, Amy had chills, headache, muscle pain, nausea, lethargy, and rash. Before further testing, Amy's healthcare provider gave her information about which of the following diseases? A. Anaplasma phagocytophilum and human granulocytic anaplasmosis B. Ehrlichia chaffeensis and human monocytic ehrlichiosis C. Shigella and dysentery D. Streptococcus pyogenes and strep throat E. Both A & B
E. Both A & B
Which of the following characteristics is NOT true of Treponema pallidum? A. Requires mammalian host B. Microaerophilic C. Causative agent of syphilis D. Solely utilizes glycolysis for energy E. Grows well on chocolate agar in the laboratory
E. Grows well on chocolate agar in the laboratory
Which is mismatched? A. Epidemic typhus - body louse feces B. Murine typhus - flea feces C. Rickettsial pox - mite bite D. Rocky Mountain spotted fever - tick bite E. Human ehrlichiosis - flea bite
E. Human ehrlichiosis - flea bite
A patient has a suspicious skin infection and a culture is taken. Which media would be appropriate to select for staphylococci? A. Nutrient agar B. Blood agar C. Chocolate agar D. MacConkey agar E. Mannitol salt agar
E. Mannitol salt agar
Swimming pool granuloma is caused by: A. Mycobacterium avium complex (MAC). B. Mycobacterium kansasii. C. Mycobacterium scrofulaceum. D. Mycobacterium fortuitum complex. E. Mycobacterium marinum.
E. Mycobacterium marinum.
Which pathogen is the most common cause of neonatal pneumonia, sepsis, and meningitis in the United States? A. Staphylococcus aureus B. Staphylococcus epidermidis C. Staphylococcus saprophyticus D. Streptococcus pyogenes E. Streptococcus agalactiae
E. Streptococcus agalactiae
A positive Quellung reaction, or capsular swelling, is confirmatory for: A. Neisseria meningitidis. B. Staphylococcus aureus. C. Streptococcus pyogenes. D. Branhamella (Moraxella) catarrhalis. E. Streptococcus pneumoniae.
E. Streptococcus pneumoniae.
All of the following pertain to tuberculosis, except: A. live bacilli can remain dormant in the lungs and reactivate later in life. B. symptoms of active TB include low-grade fever, coughing, fatigue, weight loss, and night sweats. C. lung infection can disseminate to many other organs in extrapulmonary TB. D. the BCG vaccine is used in other countries. E. antimicrobials cannot treat and cure tuberculosis.
E. antimicrobials cannot treat and cure tuberculosis.
All of the following are true about diphtheria toxin, except: A. it inhibits cellular protein synthesis. B. it must be neutralized with antitoxin. C. it primarily targets the heart and nerves. D. it is an exotoxin. E. antitoxin (DAT) comes from immunized human plasma donors.
E. antitoxin (DAT) comes from immunized human plasma donors.
All of the following pertain to Enterococcus faecalis, except: A. normal flora of the human large intestine. B. increasingly resistant to many antimicrobics. C. cause nosocomial wound infections, urinary tract infections, and septicemias. D. can cause endocarditis. E. belong to Lancefield Group B streptococci.
E. belong to Lancefield Group B streptococci.
Leptospirosis has all the following characteristics except: A. most common in cattle, horses, pigs, and dogs B. pathogen is a spirochete C. infects kidneys, liver, brain, eyes D. humans acquire it by contact with abraded skin or mucous membranes E. can be transmitted by animal bites
E. can be transmitted by animal bites
All of the following pertain to listeriosis, except: A. it causes symptoms of fever, diarrhea, and sore throat. B. it causes a serious septicemia and meningitis in the elderly, immunocompromised, and infants. C. intrauterine infection usually results in fetal death. D. adequate pasteurization and thorough cooking of food can improve prevention. E. enterotoxin of the organism causes symptoms.
E. enterotoxin of the organism causes symptoms.
The bright red rash and fever of scarlet fever is due to: A. enterotoxins. B. hemolysins. C. toxic shock syndrome toxin. D. exfoliative toxin. E. erythrogenic toxin.
E. erythrogenic toxin.
Which is not associated with tularemia? A. listed as a pathogen of concern on the lists of bioterrorism agents B. transmitted by arthropod vector C. reservoir can be rabbits and squirrels D. symptoms include fever, swollen lymph nodes, ulcerative lesions, conjunctivitis, and pneumonia E. in animals, infects the placenta and fetus
E. in animals, infects the placenta and fetus
Lepromatous leprosy: A. can cause lepromas. B. is the most disfiguring. C. pathogen grows extensively in cooler body areas, such as nose, ears, testes. D. complications include secondary infections, kidney, or respiratory failure. E. includes all of these choices.
E. includes all of these choices.
All of the following pertain to Neisseria meningitidis, except: A. virulent factors include a capsule, pili, endotoxin, and IgA protease. B. it causes serious meningitis. C. the reservoir is the nasopharynx of human carriers. D. it is more easily transmitted in day care facilities, dorms, and military barracks. E. it is a common cause of bacterial pneumonia.
E. it is a common cause of bacterial pneumonia
Which is incorrect about Yersinia pestis? A. exhibit bipolar staining B. gram-negative rod C. produces coagulase D. has a capsule E. produces enterotoxin
E. produces enterotoxin
The Argyll-Robertson pupil that is fixed and small, and does not react to light but does accommodate for focusing is associated with A. Lyme disease. B. leptospirosis. C. chlamydiosis. D. Rocky Mountain spotted fever. E. tertiary syphilis.
E. tertiary syphilis.
All the following pertain to Staphylococcus epidermidis infections, except: A. they often from an endogenous source. B. they typically occur after insertion of shunts and prosthetic devices. C. catheterization can introduce the organism and lead to urinary tract infection. D. the organism is coagulase negative. E. the organism produces a large number of tissue damaging enzymes and toxins.
E. the organism produces a large number of tissue damaging enzymes and toxins.
Which of the following pertains to both tetanus and foodborne botulism? A. it occurs when spore-contaminated soil enters deep wounds B. it is caused by enterotoxins of the pathogen C. exotoxin blocks acetylcholine release D. nausea and diarrhea are symptoms E. treatment involves antitoxin therapy
E. treatment involves antitoxin therapy
Which mechanism of nutrient acquisition is not seen in bacteria?
Endocytosis
Which of the following contributes significantly to the survival of Coxiella burnetti for long periods in the environment?
Endospore-like structure
Which bacterial structure may survive if temperatures applied during food preservation processes are too low?
Endospores
A patient develops a high fever due to a Gram-negative pathogen. Which of the following is a certain mediator of illness in this case?
Endotoxin
A microbiologist is trying to isolate a pathogen expected to be present in very small numbers from a stool specimen in which there are abundant normal microbiota. Which strategy would most likely accomplish this purpose?
Enrichment culture followed by culture on selective agar
Disinfectants are generally regulated by the
Environmental Protection Agency.
Which of the following inhibits protein synthesis?
Erythromycin
Which of the following is (are) a sterilizing gas(es) that can be used on heat-sensitive materials?
Ethylene oxide
Which of these is an agent that is used to sterilize the plastic tubing of heart-lung machines?
Ethylene oxide
Which cell type ranges in size from about 10 - 100 um, has 80s ribosomes, and has internal compartments bounded by membranes?
Eukarya
Which of the following has flagella that contain microtubules?
Eukarya
Which of the following has flagella that wave back and forth?
Eukarya
During the early stages of sporulation in Bacillus subtilis, __________ is active in the forespore and _________ is active in the mother cell.
F; E
A black eschar develops on the hand or arm of a patient with erysipeloid.
False
A cell that is Hfr and a cell that is F+ can be the same cell.
False
A given medium can be either selective or differential but not both.
False
A microbial environment containing high nutrient concentrations is called an oligotrophic environment.
False
A paroxysmal cough is associated with Legionnaires' disease. True False
False
A temperate phage always lyses its host cell.
False
Acridine orange is a purine base analogue.
False
Agents that are static and, therefore, do not kill infecting microorganisms are not useful as chemotherapeutic agents.
False
Alcohols are widely used as antiseptic and disinfectants because they are effective against endospores as well as vegetative cells.
False
All bacterial and archaeal cells are diploid.
False
All germicides are capable of killing all pathogenic organisms and endospores.
False
All prokaryotes initiate the synthesis of proteins with formylmethionine.
False
All strains of Staphylococcus aureus can produce food poisoning.
False
Although similar in function, the eukaryotic ribosome is generally smaller and more complex than the prokaryotic ribosome.
False
Although the intestinal microbiota for most people consists of the same types of organisms, the relative percentages of organisms varies significantly from person to person.
False
Ampicillin, like penicillin, must be administered by injection because it is rapidly degraded in the stomach and cannot, therefore, be given orally.
False
An individual with asymptomatic N. gonorrhoeae may not spread the disease
False
Antigenic variation is common in influenza B and C but is rare in influenza A.
False
Antiviral drugs are frequently used for the treatment of infectious mononucleosis.
False
Archaeal and Bacterial pili are identical in structure and function.
False
Archaeal flagella are superficially similar to bacterial flagella, although archaeal flagella are much thicker than bacterial flagella.
False
Archaeons power their flagella by proton motive force (PMF), whereas bacteria empower their flagella by ATP hydrolysis.
False
Bacteria growing at lower temperatures have more saturated fatty acids in their membranes.
False
Because filtration removes rather than destroys microorganisms, it does not truly sterilize the materials passing through the filter.
False
Cell walls of most Archaea and bacteria contain peptidoglycan.
False
Chlamydias and rickettsias are unusual bacteria because they do not have cell walls.
False
Coated pits containing clathrin do not permit concentration of ingested macromolecules prior to endocytosis.
False
Colonization specifically refers to the multiplication of a pathogen on or within a host, and includes the resulting tissue invasion and damage.
False
DNA replication is a complex process, and, as a result, the frequency of error is quite high.
False
Diptheria is a contagious disease that spreads from person to person mainly by the fecal-oral route.
False
Dry heat methods usually require lower temperatures and shorter exposure times than moist heat methods to achieve the same degree of killing because of the drying effects of this form of heat.
False
Due to the diversity of retroviruses, they can be placed into more than one Baltimore system group.
False
During DNA replication, deoxyribonucleosides are added to the 5' end of Okazaki fragments and to the 3' end of the leading strand.
False
During regulation of biofilm formation in Pseudomonas, cells leave the biofilm when levels of cyclic dimeric GMP are high.
False
During specialized transduction carried out by lambda phage in Escherichia coli, differences in the phage and host attachment (att) sites mediate insertion of phage DNA into host DNA.
False
Generally, exotoxins tend to be more heat stable than endotoxins.
False
Gram-positive bacteria have a structurally and chemically more complex cell wall than gram-negative bacteria.
False
Gram-positive bacteria have a thinner layer of peptidoglycan than gram-negative bacteria.
False
Helix-turn-helix and zinc fingers are secondary structural motifs in DNA and RNA, respectively.
False
Hershey and Chase used 35S-labeled protein and 32P-labeled DNA of T2 bacteriophage to infect cells of Streptococcus pneumoniae bacteria.
False
Humans are the reservoir for Borrelia hermsii.
False
Identity confirmation of Yersinia pestis by advanced laboratory techniques can be carried out in almost any hospital clinical laboratory.
False
If one left a "pasteurized" flask of broth for a long time at room temperature, it would stay sterile forever, at least in principle.
False
If you remove the peptidoglycan layer from a Gram-positive cell, it would still stain purple with a Gram stain.
False
In Escherichia coli, if 70 is not bound to RNA polymerase core enzyme, active transcription of the gene is not occurring.
False
In a disk diffusion assay for drug susceptibility, a drug producing a larger clear zone is always more effective than a drug than to one producing a smaller clear zone.
False
In a plaque assay, the number of infectious virions is usually identical to the number of virus particles present.
False
In an F+ F- mating, all or part of the host chromosome usually is transferred to the recipient.
False
In the broth dilution test, the highest concentration of the antibiotic resulting in no growth after 16 to 20 hours of incubation is the MIC.
False
In the host-parasite relationship, it is advantageous for the parasite to disable and kill its host as quickly as possible.
False
In the presence of both glucose and lactose, the lactose repressor is not bound to the operator and the genes of the lactose operon are expressed.
False
Inanimate materials involved in pathogen transmission are called reservoirs.
False
Individuals entering the room of a patient with Legionnaires' disease should wear a mask to prevent acquiring the disease from exposure to the patient.
False
Laboratory animals must be used to determine lethal and infectious doses of viruses.
False
Larger populations generally are killed as rapidly as smaller populations.
False
Legionellosis is a zoonosis. True False
False
Like bacteria and eukaryotic microorganisms, most viruses can be cultured using artificial media.
False
Like prokaryotic cells, most eukaryotic cells have an external cell wall.
False
Listeria monocytogenes does not grow in refrigerated foods.
False
Lyme disease is only seen in people living in Lyme, Connecticut.
False
Lyme disease is spread from human to human by mosquito vectors.
False
Many anaerobic Gram-negative bacteria are normally found in the duodenum.
False
Most antiprotozoan drugs have few side effects since there are numerous cellular targets found in protozoa but not found in host cells that can be targeted with antiprotozan drugs.
False
Most cases of viral gastroenteritis are accompanied by high fevers.
False
Most microorganisms live in eutrophic environments.
False
Most of the drugs used to treat protozoan infection have insignificant side effects; because protozoa are prokaryotes, the potential for drug action of host cells and tissues is less than it is when targeting bacteria.
False
Most strains of Streptococcus pyogenes produce penicillinase
False
Once the initial case has occurred, Legionnaires' disease spreads as a propagated epidemic.
False
One hundred fifty one deaths have been attributed to vCJD in the United States.
False
One strategy to overcome antibiotic resistance is to use the same antibiotics in animal husbandry as those that are prescribed for humans, since the potential for resistant bacteria to evolve would be limited to only a small number of drug classes.
False
Organisms usually have only a single transport system for any nutrient.
False
Passage of Vibrio cholerae through the human body results in reduced infectivity for the next human host.
False
People who have received the BCG immunization will generally have a negative tuberculin skin test.
False
Plague is spread from wild rodents to humans by the bite of an infected tick.
False
Plantar warts represent a sexually transmitted disease.
False
Pneumovax is a vaccine for prevention of disease caused by strains of Neisseria meningitidis.
False
Postranscriptional modification to remove introns is needed for the bacterial RNA that has codon, rather than anticodon, sequences.
False
Prior to secretion, Gram-negative bacterial proteins are translocated across one membrane while Gram-positive proteins are translocated across two membranes.
False
Protein synthesis inhibitors have a low therapeutic index because they usually cannot discriminate between prokaryotic and eukaryotic ribosomes.
False
Pseudomonas is an enteric gram negative rod. True False
False
Riboswitches regulate transcription, rather than translation, in cells.
False
Scientists first focused on gene regulation at the level of translation, rather than transcription, because more was known about protein than nucleic acids at the time.
False
Sedimentation coefficients are proportional to the molecular weight of a particle and are not affected by the volume and shape of the particle.
False
Serial dilutions can be used to estimate the total number of bacterial cells in a solution, including living and dead cells.
False
Shigellosis may not be acquired through oral-fecal routes and direct contact. True False
False
Some microbial proteins are spliced after translation in a reaction that results in removal of one or more internal intervening sequences called exteins.
False
Sulfur can be obtained from inorganic sources only.
False
The THI-element is part of the operon that controls synthesis of thymine in mRNA.
False
The binding of arabinose to the AraC protein allows it to form a loop in the DNA upstream of the ara operon promoter.
False
The cell membrane is a rigid structure that provides bacteria with their characteristic shapes.
False
The conjugation bridge in an Hfr F- mating usually breaks before chromosome transfer is complete; however, because at least part of the plasmid is transferred first, the recipient becomes F+.
False
The distribution of lipids in the plasma membrane of eukaryotes is symmetrical.
False
The genetic code is expressed differently in bacterial and archaeal cells than in eukaryotic cells.
False
The hydrocarbons found in the membranes of archaea are identical to those found in bacteria.
False
The inducer for the E. coli lac operon is allolactose produced by the action of permease on lactose.
False
The layers of peptidoglycan of the bacterial cell wall can be cross-linked by peptide intrabridges or by direct cross-linking.
False
The lower genitourinary tract is usually free of microorganisms.
False
The lower respiratory tract has a normal microbiota.
False
The molecular weights of a nucleic acid and an amino acid are approximately the same.
False
The number of N and C termini in a polypeptide chain is equal to the number of amino acids that make up that chain.
False
The original differentiation of prokaryotes and eukaryotes was based on structures found in prokaryotes that are lacking in eukaryotes.
False
The process of segregating the daughter chromosomes in Sulfolobus is more similar to the process in eukaryotic cells than in bacterial cells.
False
The purpose of the penicillin binding proteins is to link phospholipids together in the cellular membrane.
False
The relationship between Trichonympha protozoa and its termite host, and Xenorhabdus bacteria and its nematode host, are both obligatory relationships.
False
The rotation of bacterial flagella is powered by ATP hydrolysis.
False
The size and shape of a colony is not useful for identification of a microorganism because most microorganisms produce colonies that are indistinguishable from one another.
False
The skin surface is a favorable environment for colonization of Gram-negative bacteria.
False
The stop codons are translated codons; that is, they specify amino acids to be inserted into the last portion of a growing polypeptide chain.
False
The transformation frequency of very competent cells is about 10^-6, or about 1 in 1,000,000 when an excess of DNA is used.
False
There are no known human diseases that have been linked to prions.
False
There doesn't appear to be much diversity in the cell cycle processes of the Archaea, and Sulfolobus serves as an excellent model for all other Archaea.
False
To best isolate mutant bacteria that are threonine auxotrophs from a larger population, threonine-rich media should be inoculated and any colonies that form are presumptive auxotrophic mutants.
False
Transposable elements have been found only in prokaryotes and do not appear to play a major role in eukaryotes.
False
Two-component signal transduction systems are found in the Bacteria, but not in Archaea.
False
Unlike members of Bacteria, most archaeans have linear chromosomes.
False
Viruses have typical cellular structure like other living organisms.
False
Viruses infecting protists, including algae, have never been detected.
False
When a young, vigorously growing culture of bacteria is transferred to fresh medium of different composition, the lag phase is usually short or absent.
False
When tryptophan levels in a cell are low, a cell will stall transcription but continue translation of the tryptophan operon.
False
Who is usually credited with the discovery of penicillin?
Fleming
A microbiologist is working with a bacteria strain to determine if cells are competent. Cells are grown under optimal conditions with DNA fragments that carry two genes, green fluorescent protein and ampicillin resistance, and then plated to nutrient agar with and without ampicillin. Following incubation, plates are examined for fluorescent colonies under a UV lamp. Predict the results if cells are competent.
Fluorescent colonies will be present on both types of plates.
Antiseptics are generally regulated by the
Food and Drug Administration.
Who fist demonstrated transformation using mice and two strains of Streptococcus pneumoniae?
Griffith
Griffith's experiment demonstrated transformation because a mouse injected with live R and heat-killed S strains of Streptococcus pneumoniae resulted in death of the mouse and the isolation of live R as well as live S cells. Hypothesize as to the type of cells that Griffith would have observed if transformation had not occurred.
Griffith would have isolated only live R cells from the mouse host.
What type of procedure is appropriate to isolate revertants from a population of threonine auxotrophic cells?
Grow the auxotrophic cells on an agar plate without threonine; any colonies that form are presumed revertant.
___________ ______________ are required organic compounds because they are essential cell components or precursors of such components that cannot be synthesized by the organism.
Growth factors
Consider the possibility of a mutation occurring in a strain of avian influenza virus which enables the bird-specific strain to readily infect humans. Such a mutation would most likely result in changes within the ________.
HA protein
Who is credited with demonstrating unidirectional and nonreciprocal transfer of DNA between two mating E. coli cells?
Hayes
During replication, which enzyme unwinds the two strands of the DNA molecule from one another?
Helicases
Which of the following has been associated with a form of liver cancer?
Hepatitis B virus
Most E. coli antisense RNAs work with a protein called ______ to regulate their target mRNAs.
Hfq
When an F plasmid integrates into the host chromosome, the strain is referred to as
Hfr.
Which of the following is/are necessary for the replication of a satellite virus?
Host cell and helper virus
Virus morphology does not include which of the following characteristics?
Host range
What is the most likely reason why Reston ebolavirus does not cause human disease?
Human tissues lack the appropriate receptors for this viral strain.
Which of the following would be most effective and practical for routine home disinfection of a toothbrush between uses?
Hydrogen peroxide
If you wished to design an antimicrobial agent that prevented the formation of the 70S initiation complex in bacterial translation, which molecule should specifically be targeted?
IF-3
An sRNA is isolated from a bacterial cell. What would you do to determine whether it is a cis-encoded or trans-encoded sequence?
Identify whether or not the sRNA sequence is complementary to the coding strand of mRNA gene target.
Which of the following must leave the nucleus via the nuclear pore complexes?
Immature ribosomal subunits, tRNA, and mRNA
__________ alter repressor proteins thereby increasing the rate of transcription initiation.
Inducers
For a temperate phage to produce more phage, which of the following must happen?
Induction
What is the function of cyclic dimeric GMP in bacterial global regulation systems?
It acts as a secondary nucleotide messenger.
Which of the following is true about membrane filters?
It can't be depended on to remove all viruses from liquids.
All of the following statements about the periplasmic space are true except:
It is found only in gram-positive bacteria.
Which of the following is most true of a viral DNA genome?
It uses the same four nitrogenous bases found in prokaryotic and eukaryotic DNA.
If a strain of Neisseria gonorrhoeae is genetically altered such that it no longer has pili, predict how this might affect its virulence.
It will be less able to establish infection because it won't be able to adhere to host tissue.
A drug, colchicine, can be added to cells in culture and it stops the polymerization of microtubules. What effect would this have on mitosis?
It would slow or block mitosis by interfering with the spindle apparatus function.
A type of cancer associated with AIDS is __________ sarcoma.
Kaposi's
Which of the following is a disease of humans that is probably caused by a prion and was originally associated with cannibalism?
Kuru
From which body region would you expect to isolate Clostridium, Bacteroides, Fusobacterium and other anaerobic genera?
Large intestine
An experiment was done to determine the decimal reduction time of a specific population of organisms at 80 C. The data is indicated by an arrow on the graph. Which labeled line represents the likely results if the experiment was repeated using a lower temperature?
Line D
Endotoxins include which of the following?
Lipopolysaccharide
Two weeks following a hiking trip in which several ticks were noticed and numerous mosquitoes were biting, a 25-year-old man notices a rash shaped like a red ring on the back of his thigh. He was not concerned because he had no other symptoms. Three months later he noticed significant pain in his elbows and his knees. What is the most likely cause of his illness?
Lyme disease
What is the target of anthrax protective antigen (PA), edema factor, and lethal factor?
Macrophages
Which of the following is not considered a micronutrient?
Magnesium (Mg)
Which of these methods can be used to determine the number of viable microorganisms in a sample?
Measuring colony forming units per ml
Which of the following would be most appropriate for removal of bacteria and viruses from a liquid?
Membrane filter (0.01 um)
A microbiologist is testing the drinking water for a municipality. What would be the best method for testing the purified water?
Membrane filtration
________ is used to measure the amount of a chemoattractant encountered over time.
Methylation
Which of the following would you expect to find in the tonsilar crypts?
Micrococcus
Which of the following is the most common outcome of infection with polio virus?
Mild infection with fever, headache, sore throat, or asymptomatic
If a single stranded RNA virus contains genomic RNA that is complementary to the mRNA that it produces, what type of virus is this categorized as?
Minus Strand or Negative Strand is acceptable.
Which of the following types of mutation may play an important role in driving evolution because they are often nonlethal and, therefore, remain in the gene pool?
Missense
Penicillin inhibits bacterial growth by preventing the cross-linking during peptidoglycan synthesis. Why does penicillin not inhibit growth of archaeal cells?
Most archaeal cells have a cell wall, but it is not composed of peptidoglycan.
The actin-like protein that seems to be involved in determining cell shape is
MreB.
___________ are physical or chemical agents that cause mutation.
Mutagens
Leprosy is caused by a microbe of the genus ___________.
Mycobacterium
Mycobacterial infections in AIDS patients are mostly likely caused by ___________.
Mycobacterium avium complex
Which procedure is most associated with unsuccessful transformation and degradation of DNA?
Naturally-occurring transformation with DNA fragments in competent bacteria.
Pelvic inflammatory disease may result from infection with __________.
Neisseria gonorrhoeae
Several cases of an emerging infectious disease are reported in workers at a research station that borders a tropical rainforest region. The pathogen is identified as a species of bacteria carried by nematodes that infect mosquitos, and disease transmission occurs in a human host following a mosquito bite. Which organisms should be targeted in the treatment of infected patients?
Nematode and bacteria
Which of the following is not a characteristic of lipid A?
Neurotoxic
Why were the advent of metagenomics, and the application of molecular techniques such as single-cell and next-generation sequencing, important for defining a microbial relationship?
Newer methods revealed that symbiotic relationships exist between a host and one to thousands or more microorganisms, challenging the former definition of a symbiotic relationship as one that occurs between a single microbe and its host.
Which type of virus is most likely to be released by lysis of the host cell?
Non-enveloped virus
Which of the following is in the coding region of a gene?
None of the choices are correct. (promoter, leader, trailer)
Recent research has demonstrated a correlation between the presence of certain types of Gram-positive bacteria in the human gut with obesity and type 2 diabetes. These findings best support which of the following statements?
Normal microbiota may significantly impact human health and disease.
Cholera is very prevalent in all of the following areas EXCEPT _____________.
North America
Which of the following is not a major class of growth factors?
Nucleic acids
What is the most likely reason that bats, raccoons, and foxes readily become infected with the rabies virus, whereas opossums are resistant to infection?
Opossums lack the appropriate receptor for the rabies virus.
Which of the following drugs has been shown to reduce the duration and symptoms of influenza?
Oseltamivir
Which of the following is not a biological effect associated with endotoxin?
Paralysis
Which of the following is not a method of heat sterilization?
Pasteurization
Which of the following does not inhibit protein synthesis?
Penicillin
_________ are carrier proteins embedded in the membrane that increase the rate of diffusion of specific molecules across selectively permeable membranes.
Permeases
If the att site of Escherichia coli was dissimilar to that of lambda phage due to a mutation, how would transduction be affected?
Phage DNA would be unable to integrate into host DNA.
Which body defense is neutralized by the type III secretion system of Yersinia pestis?
Phagocytes
Which of the following features of a pathogen is not considered to be a virulence factor when establishing infection within host?
Pigment production
What critical role is often played by pigs in the epidemiology of influenza virus?
Pigs can become infected simultaneously with both human, avian, and swine varieties of influenza viruses, providing an opportunity for genetic recombination resulting in antigenic drift.
Which of the following structures are external to both Bacterial and Archaeal cells?
Pili
_______ formation begins with the initial colonization of the pellicle by Streptococcus gordonii, S. oralis, and S. mitis.
Plaque
If a single stranded RNA virus contains genomic RNA that is identical to the mRNA that it produces, what type of virus is this categorized as?
Plus Strand or Positive Strand is acceptable.
________ mutations affect only a single base pair in a gene.
Point
What characteristics of polio virus and infection make it possible that this disease will likely be eradicated? Check all that apply.
Polio virus has no animal reservoirs. There is an effective vaccine that prevents polio.
Which of the following methods could be used to detect the presence of viable but nonculturable cells of a pathogen in a water or food specimen?
Polymerase chain reaction
Which of the following processes is not one that is common to all symbionts?
Predation
In which situation might methylation of membrane proteins in Escherichia coli initiate a phosphorelay system that evokes clockwise rotation of flagella?
Presence of a chemorepellent in the extracellular environment.
You are studying a newly discovered prokaryotic microorganism and are attempting to determine whether it will be classified in the domain Bacteria or in the domain Archaea. All of the following would be helpful in making that distinction except
Presence or absence of double-stranded circular DNA genome
When does a cell regulate gene expression?
Pretranscription through postranslation
Which statement defends the concept that the term "gene" is better defined as a nucleotide sequence that encodes for one or more functional products rather than encoding for one or more functional proteins?
Products of genes include ribonucleotides as well as proteins.
A species of bacterium associated with the oil glands of the skin belongs to the genus
Propionibacterium
Why did scientists originally believe that proteins, rather than DNA, were the molecules that directed protein synthesis?
Proteins were the more complex molecules in which genetic information could be stored.
During sporulation in Bacillus subtilis, inactive precursor forms of new sigma factors are activated at the appropriate time by which mechanism?
Proteolysis
____________ is a peptidoglycan-like molecule found in the cell walls of some archaea.
Pseudomurein
Predict the experimental outcome if Hershey and Chase had used a bacterial cell instead of a bacteriophage in the procedure.
Radioactivity would be detected in the supernatant but not in the pellet.
___________ mutations occur in the promoter or operator region of a gene or set of genes and affects the expression of the downstream genes without affecting the amino acid sequences of the gene products.
Regulatory
What term describes a set of genes that is controlled by a common regulatory protein?
Regulon
In which of the following stages of the viral infectious cycle do enveloped viruses usually acquire their envelopes?
Release
How could the Hershey and Chase experimental procedure be re-designed to support the hypothesis that RNA rather than DNA was the transforming agent?
Replace T2 bacteriopage with an RNA virus.
In the Hershey and Chase experiment, how did labeling DNA and protein with different radioactive isotopes demonstrate that DNA, rather than protein, carried the genetic information in the T2 virus?
Researchers could track which part of the virus entered a bacterial cell.
Which of the following is caused by a member of the rickettsias?
Rocky Mountain spotted fever
Which of the following proteins is central to starvation survival strategies in many bacteria?
RpoS
A(n) _________ layer is a layer of protein or glycoprotein that exhibits a pattern resembling floor tiles.
S
Which of the following is the most error-prone of the repair mechanisms?
SOS repair
Which of the following encodes its own capsid proteins?
Satellite virus
Which stage of syphilis is characterized by a skin rash?
Secondary
_________ membranes allow some molecules to pass but not others.
Selectively permeable
Which of the following are exceptions to the universal genetic code that is used by most organisms?
Selenocysteine Pyrrolysine
Serratia marcescens bacteria has a gene that regulates red pigment production by cells. A student inoculates two nutrient agar plates of Serratia and incubates one at 25 C and the other at 37 C. Following incubation, the student observes that colonies on the 25 plate are red while those on the 37 C plate are nonpigmented. Which of the following statements is a logical conclusion based on these results?
Serratia genes for pigment production are induced at certain temperatures.
What type of lifestyle is demonstrated by bacteria in biofilms?
Sessile
Which of the following is not usually involved with the spread of staphylococci?
Sexual intercourse
A consensus sequence in the untranslated leader sequence of a prokaryotic mRNA which serves as a ribosome binding site is called the __________-___________ sequence.
Shine-Dalgarno
___________ are activities of a chemotherapeutic agent that damage the host either by inhibiting the same process in the host as in the target cell or by damaging other processes.
Side effects
___________ bind ferric iron and transport it into a bacterial cell.
Siderophores
From which of the following body sites would you expect to isolate Staphylococcus, Propionibacterium, Streptococcus and Corynebacterium as the primary colonizing microbiota?
Skin
Which of the following is the most unique aspect of archaeon cell envelopes?
Some archaeons have lipid monolayers in their plasma membrane.
Which statement correctly explains the Gram stain reaction of archaeal cells?
Some are Gram-positive and some are Gram-negative due to the diverse chemical structure.
When an F+ plasmid acts as the donor in a mating, which of the following do(es) not happen?
Some chromosomal genes not on the plasmid are transferred.
Which statement correctly describes archaeal cell walls?
Some have an outer layer of complex polysaccharide and some have an outer layer of protein.
Which of the following represent(s) the way(s) in which enveloped viruses acquire their envelopes?
Some viruses bud through the plasma membrane while other bud through internal cellular membranes.
How do spheroplasts and protosplasts differ?
Spheroplasts retain their outer membrane but protoplasts do not.
Which cellular shape is seen among members of domain Bacteria that is not found among the domain Archaea?
Spiral or corkscrew shapea
During sporulation in Bacillus subtilis, the response regulator that positively controls many genes needed for sporulation and negatively controls genes not needed during sporulation is
SpoOA.
_________ is the process through which endospores are formed within a vegetative cell.
Sporulation
The concept of a prokaryote was first fully outlined in 1962 by
Stanier and Van Niel.
Staphylococcal food poising is caused by the ingestion of improperly stored or cooked food in which _________ has grown.
Staphylococcus aureus
Which of the following is not a major cause of meningitis cases in the United States?
Staphylococcus aureus
What method was used to inoculate the plate shown here?
Streak plate
Which of the following is not a mechanism of quorum sensing in Vibrio?
Stringent response
Guanine tetraphosphate (ppGpp) is particularly associated with which process?
Stringent response in Escherichia
Which of the following is normally treated by antifungal creams and solutions?
Superficial mycoses
A neuraminidase inhibitor called ________ is sometimes used in the treatment of people infected with influenza viruses.
Tamiflu
Which of the following is a region of DNA at the end of a linear chromosome?
Telomere
Consider an antibacterial drug. In which of the following cases would the action of the drug be considered primarily bacteriostatic?
The MLC is 10-20 times higher than the MIC.
Which of the following did not play a role in the eradication of smallpox?
The availability of effective antiviral agents that block replication.
A strain of Neisseria gonorrhoeae has undergone a mutation and is no longer able to make pili. Predict the most likely outcome.
The bacteria will become less virulent and will not be able to readily establish infection.
Which of the following is the correct order for binary fission?
The cell elongates, replicates its chromosome, and separates the chromosome into the two parts of the cell, and a septum forms at midcell.
Select the correct statement about archaeal ribosomes.
The chemical components of archaean ribosomes are more similar to those of eukaryotic ribosomes than to those of bacterial ribosomes.
How is the cell cycle of Sulfolobus spp. similar to that of eukaryotes?
The cytokinesis process in Sulfolobus is similar to the process in eukaryotes.
How is budding of bacteria to produce daughter cells different from binary fission?
The cytoplasmic division is unequal.
An Hfr cell and an F- cell result from conjugation between a donor cell and a recipient cell. Which statement is false regarding this event?
The donor could have been either F- or F+.
Which of the following represents the best definition of microbial death?
The organism will not grow on a medium that normally supports its growth.
A microbiologist is attempting to determine the size of a microbial population and has employed several methods. She noticed that the direct count she obtained using a counting chamber and microscope was much higher than her estimate from doing a viable plate count. This discrepancy was encountered during multiple trials. What is the most likely reason for the discrepancy?
The organisms were not readily cultured on the viable count, either because many were dead or because the medium and growth conditions used for the viable count will not support the growth of the microorganism.
Predict how the plasma membrane fatty acid composition would change as the temperature of the habitat of an aquatic bacterial species warms from 2 C to 15 C during the spring and summer months.
The percentage of saturated fatty acids would increase.
Which of the following is not true of specialized transduction?
The phage genome retains the full complement of phage genes.
Predict the change in surface area and volume of a spherical cell if the diameter of the cell doubles:
The surface area will increase by a factor of 4, while the volume will increase by a factor of 8.
Which one of the following contributes to the utility of the strains of Salmonella typhimurium used in the Ames reversion assay?
They are highly permeable to test substances.
Which of the following is not true of bacterial plasmids?
They are required for host growth and/or reproduction.
Which of the following is/are not true about viral envelopes?
They are typical lipid monolayers with embedded viral proteins.
Which of the following is true of viruses in the extracellular phase?
They behave as a macromolecular complex and are no more alive than are ribosomes.
Which of the following is not true about archaeal ribosomes?
They have similar antibiotic sensitivities to those of bacteria.
Which is not true of viruses?
They infect animal and plant cells only.
Which of the following is not a mechanism by which viruses cause cancer?
They produce defective interfering particles.
Which of the following is correct about the protease inhibitor drugs designed to treat HIV infection?
They slow the progress of the disease
One type of archaeon, Haloquadratum walsbyi, is shaped like a postage stamp with dimensions of 2 um x 3 um x 0.25 um. What advantage would this shape provide?
This shape increases the surface to volume ratio enabling more efficient nutrient uptake.
How many different termination codons are used in translation?
Three
Which type of medium support growth of mutant bacteria that are threonine auxotrophs?
Threonine auxtrophs only grow on media that is supplemented with threonine.
Predict the outcome of protein synthesis if a gene undergoes a mutation in its anticodon region where a charged tRNA recognizes a nonsense mutation.
Transcription and translation both would continue.
If chromosomal DNA from a host is the only type of DNA carried by a transducing particle, what can be concluded regarding transduction in this case?
Transduction in this case is generalized rather than specialized.
If chromosomal DNA from a host and phage DNA are carried by a transducing particle, what can be concluded regarding transduction in this case?
Transduction in this case is specialized rather than generalized.
________ molecules deliver amino acids to ribosomes during translation.
Transfer RNA (tRNA)
Which is true regarding translation in bacteria?
Translation begins with formation of the 30S initiation complex.
How do translational riboswitches and transcriptional riboswitches differ?
Translational riboswitches are mainly observed in Gram-negative bacteria while transcriptional riboswitches are associated with Gram-positive bacteria.
A bacterial cell that secretes proteins by types II and V systems is most likely Gram-negative.
True
A biological safety cabinet filters out more microorganisms than a N95 mask.
True
A common type of autoinducer found in gram-negative bacteria are acyl homoserine lactones (AHL).
True
A drug that disrupts a microbial function not found in animal cells usually has a higher therapeutic index.
True
A eukaryotic flagellum can either push a cell through a liquid environment or pull it through depending on the undulating pattern of movement.
True
A germfree mouse that is not born by cesarean section is not a suitable animal model for investigating the interaction between a host and one type of bacteria.
True
A variety of free-living amoebae and ciliated protozoa are thought to provide a natural reservoir for survival and growth of Legionella spp. in nature.
True
All of the colonies form on the surface of a spread plate, whereas on a pour plate, colonies may be embedded in the agar as well as on the surface.
True
Anthrax is a highly infectious disease of animals that can be transmitted to humans who come in direct contact with infected animals or their products.
True
Approximately half of known animal carcinogens can be detected by the Ames test.
True
Arthropod-borne encephalitis would show less seasonality in a tropical or subtropical climate than what is seen in a temperate climate.
True
Available evidence is consistent with the proposal that prion diseases are caused by infectious proteins.
True
Bacteria in biofilms or abscesses may be replicating very slowly and are therefore resistant to chemotherapy because many agents affect pathogens only if they are actively growing and dividing.
True
Bacterial chromosomes, unlike eukaryotic chromosomes, often consist of a single replicon.
True
Bacterial vaginosis may be the result of transfer from the rectum where the causative organisms usually reside in addition to occurring by means of sexual transmission.
True
Betapropiolactone is not as useful as ethylene oxide as a sterilizing agent because it does not penetrate materials as readily as ethylene oxide.
True
Blood agar is both a differential and enriched medium.
True
Botox injections contain botulin toxin.
True
By using enzymes that destroyed DNA, RNA, or protein, Avery and colleagues were able to determine which of the three molecules were required to transform bacterial cells.
True
Catananes are interlocked chromosomes that form during the termination stage of DNA replication.
True
Chlamydia trachomatis is commonly transmitted by direct sexual activity.
True
Chlamydia trachomatis is the most prevalent single cause of blindness resulting from an infectious agent.
True
Chlamydiosis can lead to endometritis, salpingitis, and pelvic inflammatory disease.
True
Chloroplasts are the site for both the light and dark reactions of photosynthesis.
True
Coinfection with HIV and Human Herpesvirus 8 (HHV-8) can greatly promote the development of cancer in AIDS patients.
True
Copper (Cu) is considered a micronutrient.
True
Coral bleaching where the photosynthetic endosymbiont is lost or becomes non-functional can be caused by temperature increases as small as 2 C.
True
Creutzfeldt-Jacob disease is known to have been transmitted by surgical instruments and transplanted nerve tissue.
True
Debridement of diseased tissue is important in the care of patients with gas gangrene.
True
Dental caries is the most common human disease.
True
Different transport systems for the same nutrient that are part of the same organism are usually regulated in different ways.
True
Diptheria exotoxin is made only by strains of Corynebacterium diptheriae that carry a prophage containing the tox gene.
True
During regulation by attenuation in the trp operon, if the pause and terminator loops form in mRNA, transcription is uncoupled to translation and protein synthesis is not occurring.
True
During the cell division process, Sulfolobus segregates its chromosomes in a manner similar to bacteria, and performs cytokinesis in a manner similar to that of eukaryotes.
True
During tryptophan synthesis in Escherichia coli, the 1:2 attenuator sequence of mRNA is called the pause loop.
True
Electron transport reactions that occur in the mitochondria of eukaryotes take place on the inner membrane of that structure.
True
Endotoxic shock, resulting from the release of endotoxin by bacteria infecting a patient, is only caused by Gram-negative bacteria.
True
Eukaryotes usually have more than one chromosome for the storage of genetic information.
True
Fecal transplants have been successfully used to treat Clostridium difficle colitis by reintroducing healthy fecal microbiota that outcompete the C. difficile.
True
Fever response can be triggered by an endogenous pyrogen called interleukin-1.
True
Food intoxication usually has a shorter incubation period than food-borne infection.
True
Gene regulation during sporulation in Bacillus subtilis involves BOTH temporal and spatial control.
True
Genes for antibiotic resistance can be found in antibiotic-producing bacteria as well as in non-antibiotic-producing bacteria.
True
Growth factors cannot be synthesized by the bacteria that use them and include amino acids, pyrimidines, and vitamins.
True
Heavy metals are effective antimicrobial agents but are not widely used because of their high toxicity to humans.
True
Heavy metals may inactivate proteins by reacting with their sulfhydryl groups.
True
Hepatitis can be caused by cytomegalovirus and Epstein-Barr virus as well as by the hepatitis viruses.
True
If 5-bromouracil was added to a culture of actively dividing bacterial cells, resulting mutations could eventually become a stable part of the cellular genome.
True
If the DNA of a new discovered organism exhibits genes that are arranged as operons and lacks intron sequences, the hypothesis that this organism is bacterial rather than mammalian would be supported by the evidence.
True
Impetigo involves itching papules that break and form a very contagious yellow crust.
True
In an HFR F+ mating, the conjugation bridge usually breaks before chromosomal transfer is complete. Therefore, the recipient remains F-.
True
In both botulism and tetanus, respiratory muscles cannot facilitate breathing and, if untreated, respiratory collapse leads to death.
True
In order for successful antibiotic therapy, the in vivo level of the antibiotic must be greater than or equal to the MIC.
True
In severe cases of Rocky Mountain spotted fever, the enlarged lesions of the rash can become necrotic and predispose the patient to gangrene of toes and fingertips.
True
In the mechanics of conjugation, exclusive of gene transfer, Hfr and F+ strains behave the same.
True
Insects frequently contain bacteria in their cytoplasm, and these bacteria form a mutualistic association with their host.
True
It is theorized that rheumatic fever and acute glomerulonephritis could be the result of antibodies to Group A streptococci that cross-react with patient tissues.
True
Local Staphylococcus aureus infections often involve formation of an abscess.
True
Lysosomes maintain an acidic environment by actively pumping protons into their interior.
True
Macrophages are phagocytic cells.
True
Many archaeal genomes include chromosomes and plasmids.
True
Membranes of some thermophilic Archaea are stabilized by ether linked phospholipids.
True
Methanogens may contribute to the greenhouse effect and global warming due to methane production.
True
Metronidazole is used to treat Entamoeba infections.
True
Microorganisms show differential sensitivity to antimicrobial agents.
True
NGU is a syndrome among males with chlamydial infections of the urethra.
True
Neisseria meningitidis and Neisseria gonorrhoeae are fastidious, gram-negative cocci that produce oxidase.
True
New cases of tuberculosis are frequently the result of reactivation of old dormant infections.
True
Nitrogen can be obtained from either organic or inorganic sources.
True
Non-toxin-producing strains of Corynebacterium diptheriae could infect the body but would not cause the typical symptoms of diptheria.
True
Obligate anaerobes are usually poisoned by molecular oxygen but may grow in aerobic habitats if associated with facultative anaerobes that use up all available oxygen.
True
One of the major advantages of a continuous culture system is that the cells can be maintained in the exponential growth phase for extended periods of time.
True
Penicillin G is frequently injected but not normally given orally because it is rapidly degraded in the stomach.
True
Permease proteins that aid in the transport of nutrients resemble enzymes in their specificity for the substance to be transported. Each carrier is selective and will transport only a closely related set of substances.
True
Photoreactivation repairs thymine dimers by splitting them back into separate thymines.
True
Plague is a quarantinable disease. True False
True
Prions consist of proteins and have no apparent nucleic acid genome.
True
Prokaryotes were once described based on structures that were present in eukaryotes, but absent in prokaryotes.
True
Propionibacterium acnes is normal flora of sebaceous glands of the skin.
True
Proteus species often cause urinary tract infections. True False
True
Pseudomonas aeruginosa is resistant to many antimicrobics. True False
True
Ribosomes are not considered to be organelles because they are not bounded by a membrane.
True
Sepsis and septic shock cannot be categorized under a specific mode of transmission.
True
Septic shock is actually the result of endogenous mediators released from the patient's own cells in response to bacterial endotoxins or exotoxins.
True
Signal recognition particles (SRPs) are associated with the Sec translocation system.
True
Small RNAs that regulate translation by binding to the leader region of mRNAs are called antisense RNAs.
True
Some archaeal cells lack a cell wall.
True
Some archaeons are symbionts in animal digestive tracts.
True
Some photosynthetic bacteria produce gas vacuoles that regulate their buoyancy but contain no lipid.
True
Sterol-like molecules called hopanoids are thought to be important for the structural integrity of many bacteria because of their suspected role in membrane stabilization.
True
The B form of the DNA double helix contains a wider major groove and a narrower minor groove because the two polynucleotide strands are not positioned directly opposite one another in the helical cylinder.
True
The Enterobacteriaceae do not produce oxidase compared to the pseudomonads that do produce oxidase. True False
True
The Epstein-Barr virus is the etiologic agent of infectious mononucleosis.
True
The IMViC series of biochemical tests are used to identify the Enterobacteriaceae. True False
True
The Tat and Sec pathways are protein translocation systems.
True
The average adult carries 10 times more microbial cells (10^14) than human cells (average about 10^13).
True
The basic differences between RNA and DNA reside in their sugar and pyrimidine bases; RNA has ribose and uracil whereas DNA has deoxyribose and thymine.
True
The effects of most antimicrobial drugs are greater if the microorganisms are actively growing.
True
The endoplasmic reticulum is mostly devoid of ribosomes (smooth) when cells are producing large quantities of lipid.
True
The extreme insolubility of ferric iron leaves little free iron available for transport into bacterial cells.
True
The fermentation by-products of Clostridium perfringens can destroy muscle structure in myonecrosis.
True
The formation of intranuclear inclusion bodies is associated with cytomegalovirus infection.
True
The growth rate of a given species of microorganisms is dependent on the composition of the medium in which it is grown
True
The highest numbers of cases of Rocky Mountain spotted fever occur along the eastern seaboard.
True
The initiator tRNA of the bacterium Escherichia is a modified form of the initiator tRNA used by yeast Saccharomyces.
True
The largest of the viruses are similar in size to some small bacteria and are large enough to be seen with a light microscope
True
The major difference between the vacuoles of eukaryotes and the inclusion bodies of prokaryotes is that the former are membrane-bound, whereas the latter are not.
True
The majority of mitochondrial proteins are manufactured under the direction of the nuclear DNA by cytoplasmic ribosomes.
True
The mechanism of pathogenesis by prions may involve a conformational change in the prion protein (PrP) to an abnormal form.
True
The membrane bound structure that contains the chromosomes of eukaryotes is called the nucleus.
True
The minimum lethal concentration (MLC) is the lowest concentration of drug from which organisms fail to recover when removed from the drug.
True
The most common capsid morphologies are icosahedral and helical.
True
The most likely mode of transmission of the common cold is by hand-to-hand contact between a rhinovirus donor and a susceptible recipient.
True
The noncoding sequences located between the start codon and the stop codon in interrupted genes are called introns.
True
The nucleolus is a highly active region of the nucleus that is required for synthesis of ribosomes.
True
The only organisms to produce endotoxins are Gram-negative bacteria.
True
The oral cavity of humans normally becomes colonized with microorganisms within hours after birth.
True
The pathogen that causes Legionnaires pneumonia also causes a milder infection called Pontiac fever. True False
True
The rate of killing by an antimicrobial agent may slow when the microbial population has been greatly reduced because the remaining population may have a high proportion of resistant organisms.
True
The spirochete of relapsing fever changes cell surface antigens many times in order to avoid destruction by the immune response.
True
The term "sexually transmitted infection" is more accurate than "sexually transmitted disease" because it is a sexually transmitted pathogen may colonize host tissues without causing further damage to the host.
True
The trace amounts of micronutrients needed by microorganisms are usually supplied as inadvertent contaminants in water and regular media components.
True
Treatment of fungal infections is more difficult than treatment of bacterial infections because the greater metabolic similarity between the fungi and their hosts limits the ability of a drug to have a selective toxicity.
True
Virus receptors are often not distributed uniformly over the surface of host cells, but are instead concentrated in lipid rafts.
True
Viruses in the extracellular state possess few, if any, active enzymes.
True
Viruses such as MS2 and QB pack additional information into their genomes through the use of overlapping genes.
True
Warts or verrucae are caused by the papillomaviruses.
True
When a young, vigorously growing culture of bacteria is transferred to fresh medium of the same composition, the lag phase is usually short or absent.
True
When assessing the role of conjugative bacteria in the spread of antibiotic resistance genes, it is fair to say that Hfr cells contribute most while F- cells contribute least.
True
While establishing a symbiotic relationship, plant hosts communicate via secretion of flavonoids and bacteria release Nod factors to communicate with the plant.
True
While exotoxin production is most generally associated with Gram-positive bacteria, some Gram-negative bacteria also produce exotoxins.
True
A 45-year old man living in Arkansas made an appointment with his physician after developing several ulcerative lesions on his hands. He also had a high fever and swollen axillary lymph nodes. When taking the patient's medical history, the physician made note of the fact that the man had been hunting rabbits a week earlier, regularly drank unpasteurized milk, and had not received any vaccines since his childhood. What is the most likely cause of the man's current symptoms.
Tularemia
Select the secretion systems are found in both Gram-positive and in Gram-negative bacteria.
Type I Type IV
Which set of codons terminate transcription in most organisms?
UGA, UAG, UAA
A microbial geneticist observes that a significant number of pyrimidine dimers are present in bacterial DNA following exposure to a particular mutagen. To which mutagen were the bacterial cells likely exposed?
UV light
Portable UV room sterilizing units are being used to reduce endospores of Clostridum difficile in patient hospital rooms after patients have vacated their rooms. Which of the statements best describes this application?
UV radiation will destroy C. difficle endospores assuming it is applied for a long enough period and directly contacts all surfaces.
Which of the following lacks sufficient penetrating power for bulk sterilization?
Ultraviolet (UV) radiation at 260 nm
Which of the following nitrogenous bases is usually found in RNA but not in DNA?
Uracil
Which of the following drugs is (are) effective against cold sores?
Valcyclovir and acyclovir
Which of the following methods of genetic recombination is common to both eukaryotic and bacterial cells?
Vertical gene transfer
Who should be vaccinated against rabies?
Veterinarians
Which of the following might be missed if viable counts are done on food and/or water specimens?
Viable but nonculturable cells
A microbiologist is studying the growth of a particular strain of bacteria to determine when it will transition from exponential growth to stationary phase and from stationary phase to death phase. Which of the following methods of measuring microbial growth would be best for this purpose?
Viable plate count
Which of the following is not true of viruses?
Viruses replicate by binary fission.
Which of the following is the major reason why it has been difficult to treat viral infections with chemotherapeutic agents?
Viruses use the metabolic machinery of their hosts, which limits many of the potential points of attack.
What is the predominant symptom of staphyloccocal food poisoning?
Vomiting
Which of the following is the most notable symptom of infection with Norovirus?
Vomiting
Whose discovery of streptomycin stimulated an intense search for other antibiotics?
Waksman
The causative agent of bubonic plague is _____________.
Yersinia pestis
During cytokenesis, a critical step in separation is the assembly of the
Z ring.
Which of the following is sometimes useful against viral infections?
Zidovudine
Lipids with polar and nonpolar ends are said to be
amphipathic.
Export of flagellin subunits is mediated by
an apparatus in the basal body of the flagellum that is related to the type III secretion pathway.
A newly discovered microorgansim has a circular chromosome that is complexed with histones, but not enclosed within a membrane. The plasma membrane lipids include glycerol diethers and diglycerol tetraethers. There are no mitochondria or chloroplasts, but the cells do contain 70s ribosomes. The microbe most likely is
an archaeon.
The rash associated with German measles is most likely caused by
an immunological reaction to the virus.
The condition in the host that results from pathogenic parasitic organism growing and multiplying within or on the host is called
an infection
A transposable element composed of an antibiotic resistance gene, a recombinase gene, and inverted repeats is identified in a bacterial genome. This element can be any of the following except
an insertion sequence.
An F+ plasmid results when
an integrated F plasmid is incorrectly excised, bringing host genes with it.
Organisms that grow in the mud under relatively nonturbulent bodies of water are likely to be
anaerobes.
Chemotherapeutic agents that are natural products of microorganisms are most specifically referred to as ___________.
antibiotics
The portion of the tRNA molecule that binds to the codon on the mRNA is called the
anticodon.
A(n) _________ is a drug that blocks the function of a metabolic pathway.
antimetabolite
The two strands of a DNA molecule are ________; that is, they are oriented in opposite directions.
antiparallel
Bioluminescence in Vibrio harveyi is due to an alternate stigma factor that prevents _______ from binding to Lux mRNA, thus allowing translation of bioluminescent genes.
antisense
The prevention of infection caused by microorganisms is called
antisepsis.
A neutralizing antibody against a toxin is called a(n) __________.
antitoxin
Diptheria is treated with
antitoxin and antibiotics
Pseudonocardia is an organism that is hosted by
ants that cultivate fungal gardens.
Diglycerol tetraether lipids
are a characteristic feature of thermophilic Archaea.
In humans, equine encephalitis can present as a spectrum from fever and headache to _________ ___________ and encephalitis.
aseptic meningitis
The __________ is a factor-independent termination site found in the leader region of certain operons, which, under the influence of ribosome behavior, controls the continued transcription of that operon.
attenuator
Acylhomoserine lactones used in quorum sensing regulate their own synthesis by a(n) ____________ system.
autoinduction
A(n) _________ is a special type of lysosome used by a cell to selectively digest and recycle cytoplasmic contents, such as mitochondria.
autophagosome
The term used to describe bacteria that are rod-shaped is
bacillus.
The most selective antibacterial agents are those that interfere with bacterial cell wall synthesis. This is because
bacterial cell walls have a unique structure not found in eukaryotic host cells.
Moist heat sterilization at 1000 kills all of the following EXCEPT
bacterial endospores.
An agent that kills bacteria is referred to as __________.
bactericidal
Bacterial pathogens may be controlled by ___________, which are viruses that specifically infect and lyse the bacterial host.
bacteriophage or phage
An agent that prevents the growth of bacteria without causing irreversible damage to the bacteria is referred to as __________.
bacteriostatic
Organisms that grow near deep-sea volcanic vents are likely to be
barophilic or barotolerant.
Organisms that require increased pressure for optimum growth are called
barophilic.
Organisms that are not drastically affected by increased pressure are called
barotolerant.
Construction of flagella and/or cilia is directed by the
basal body.
Bacterial flagella are composed of three parts: the _________ body, which is embedded in the cell, the hook, and the ___________, which is the longest part of the flagellum.
basal; filament
A culture in a closed vessel to which no additional medium is added and from which no waste products are removed is called a _________ culture.
batch
When the Catabolite Activator Protein binds to its binding site in DNA, it
bends the DNA.
Some complex viruses have icosahedral symmetry in the head region and helical symmetry in the tail. Overall, these viruses are said to have __________ symmetry.
binal
Most bacterial and archaeal cells divide by
binary fission
Aminoglycoside antibiotics
bind to the 30S ribosomal subunit.
With respect to orthomyxoviruses, changes in antigenicity usually occur as a result of
both antigenic drift and antigenic shift.
Genes for the drug resistance may be present
both on the chromosome and on plasmids.
Twitching or gliding motility involves
both type IV pili and movement of slime can be involved in twitching or gliding motility.
Negri bodies are produced within ________ of rabies-infected humans.
brain neurons
When a chemotherapeutic agent is effective against many different pathogens, it is said to be a __________ antibiotic.
broad-spectrum
A(n) __________ is an enlarged lymph node that appears during cases of the plague.
bubo
In order for high level expression of the E. coli lac operon to occur, a complex of catabolite activator protein and __________ must be bound to the DNA near the promoter.
cAMP or cyclic AMP
The Ames test
can be used to measure the mutagenicity of chemicals.
The protein coat surrounding the viral genome is called the
capsid
Icosahedral viruses are constructed from ring- or knob-shaped units called __________.
capsomers
A _________ is a polysaccharide layer that lies outside the cell wall and is not easilt removed.
capsule
Sortase is a protein enzyme of bacteria that
catalyzes covalent attachment of some surface proteins to peptidoglycan.
A diffuse, spreading infection of subcutaneous skin tissue is _______.
cellulitis
In the primary stage of syphilis, the initial symptom is a small, painless, reddened ulcer called a ___________.
chancre
Proteins that recognize unfolded polypeptides and help them fold into their proper conformations are called _______________.
chaperones
The organelle responsible for harvesting light as an energy source for photosynthesis is the
chloroplast.
The Golgi apparatus is comprised of flattened, saclike structures called __________, which may be clustered in one region or scattered throughout the cell.
cisternae
The endoplasmic reticulum is composed of flattened sacs called
cisternae
Each of the following plays a role in the recycling of proteins in a cell EXCEPT
clathrin
Staphylococci can be divided into pathogenic and relatively nonpathogenic strains based on whether or not they synthesize __________.
coagulase
The term used to describe bacteria that are intermediate in shape between spherical and rod-shaped is
coccobacilli.
The term used to describe bacteria that have a spherical shape is
coccus.
The transcribed and translated region of a gene is the ________ region.
coding
Macroscopically visible growths or clusters of microorganisms on solid media are called ___________.
colonies
When counting colonies during viable cell counts, the results are expressed as _________ ____________ _________ because it is impossible to determine that each colony arose from a single cell.
colony forming units
When Nitrobacter utilizes nitrite produced from ammonia by Nitrosomonas to obtain energy by converting the nitrite to nitrate, the relationship between the two organisms is
commensal
In order to take up a naked DNA molecule, a cell must be __________, which may occur only at certain stages in the life cycle of the organism.
competent
Media containing some ingredients of unknown chemical composition are called __________ media.
complex
Lethal mutations can be recovered in haploid organisms if they are
conditional.
Transfer of genetic information via direct cell-cell contact is called
conjugation
Plasmids that have genes for pili and can transfer copies of themselves to other bacteria during conjugation are called __________ plasmids.
conjugative
Key sequences exist within promoters, which vary somewhat among various promoters but are sufficiently constant that they can be represented by a sequence of bases most often found at each position. These representations are called __________ sequences.
consensus
A feature unique to some archaeal plasma membranes is that they may
consist of a lipid monolayer.
A physical relationship where an organism hosts more than one symbiont is known as a
consortium.
Enzymes that are expressed at a constant level all the time are said to be ____________.
constitutive
A culture system with constant environmental conditions maintained through continual provision of nutrient and removal of wastes called __________ culture system.
continuous
Mussels and sponges sometimes contain methanotrophs as intracellular symbionts because the methanotrophs
convert methane to carbohydrate for use by the host.
Although heavy metals are no longer widely used as germicides, __________ is an effective algicide in lakes and swimming pools.
copper sulfate
The region of the cell bounded by the plasma membrane is the __________.
cytoplasm
Time required to kill 90% of microorganisms or spores in a sample at a specified temperature is the
decimal reduction time (D value).
The natural host(s) for Borrelia burgdorferi is/are _________.
deer and field mice
Media in which all components and their concentration are known are called __________ media.
defined
The genetic code is said to be _________ because more than one codon will specify a particular amino acid.
degenerate
Moist heat sterilizes by
denaturing proteins.
The disease caused by Streptococcus mutans is
dental decay or caries
Receptor mediated endocytosis
depends on formation of clathrin coated pits that pinch off and is used to internalize molecules such as hormones, growth factors, iron, and cholesterol.
Amphipathic organic molecules that serve as disinfectants by disrupting membranes and denaturing proteins are called
detergents.
In some circumstances, when two different carbon sources are available, growth will occur first using one carbon source, then after a short lag period, growth will resume using the second carbon source. This process is called __________ growth.
diauxic
Stacks of cisternae in the Golgi apparatus are referred to as
dictyosomes
A growth medium that distinguishes among different groups of bacteria on the basis of their biological characteristics is called a ________ medium.
differential
Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes); nonhalophiles will not grow. Among the halophiles, mannitol fermenters will produce acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol fermenter and halophilic mannitol nonfermenter. In this case, the medium is acting as (a) _______ medium(s).
differential
The cell membranes of wall-less archaeons are strengthened by
diglycerol tetraethers.
In a continuous culture system, the rate at which media is added and removed is called the _________ rate.
dilution
The substantial reduction of the total population of microorganisms on inanimate objects and the destruction of potential pathogens is called
disinfection.
Prions are of significance because they cause infections of
domestic animals and humans.
Human cancer causing viruses most often have a ___________ genome.
dsDNA
Colonies grow most rapidly at the __________ where oxygen and nutrients are readily available; however, they grow less rapidly at the __________ where these materials have been depleted.
edge, center
Cilia beat with two distinctive phases. With the __________ stroke, they stroke like an oar, thereby propelling the organism through the water. With the __________ stroke, cilia bend along their length while they are pulled forward.
effective, recovery
The nucleic acids carried by viruses usually consist of
either DNA or RNA.
The total number of viable microorganisms remains constant in stationary phase because
either there is a balance between cell division and cell death or there is a cessation of cell division even though the cells may remain metabolically active.
Nonenveloped viruses most often gain access to eukaryotic host cells by
endocytosis
The genome of a recipient cell is called a(n) ____________.
endogenote
Eukaryotic ribosomes may be free in the cytoplasm or attached to the ________.
endoplasmic reticulum
Ribsomes synthesizing proteins that are to be excreted are located on the ________.
endoplasmic reticulum
The major site of cell membrane synthesis is the
endoplasmic reticulum.
Endospores represent a challenge to the fields of industrial and medical microbiology because
endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive, and endospore-forming organisms are often dangerous pathogens.
Because LPS is bound to the surface of bacteria, it is called a(n) __________.
endotoxin
The lipopolysaccharide (LPS) that is found in the outer membrane of gram-negative bacteria is also known as
endotoxin.
A culture technique that encourages the growth of specific microbes while inhibiting the growth of others is a(n) ____________ culture.
enrichment
In the rumen, food is quickly attached by cellulase
enzymes produced by microbes.
By definition, if the DNA of a cell undergoes a spontaneous mutation, it was NOT due to
exposure to radiation.
Organisms that grow best at pH levels above 10 are called ______________ ______________.
extreme alkaliphiles
The movement of molecules across a membrane from an area of higher concentration to an area of lower concentration with the use of carrier molecule embedded in the membrane is called
facilitated diffusion.
Organisms that do not require oxygen for growth but grow better in its presence are called
facultative anaerobes.
Membranes of thermophilic bacteria are stabilized by phospholipids with
fatty acids that tend to be more saturated.
Infectious hepatitis (hepatitis A) is usually transmitted by
fecal-oral contamination of food or drink.
Congenital rubella syndrome usually occurs in the time frame of the
first semester of pregnancy.
Long filaments containing microtubules and used for cellular locomotion are called __________ whereas short fibers containing microtubules and used for cellular locomotion are called __________.
flagella, cilia
The most widely accepted current model for membrane structures is called the _____________________ model.
fluid mosaic
When a protein is synthesized, cis- or trans-splicing of that protein occurs
following translation
Bacteria reproductive strategies include all of the following EXCEPT
fusion of two bacterial cells that then split into four uninucleate cells.
Growth media that will support the growth of many different types of microorganisms are called __________ __________ growth media, whereas those that are supplemented by blood or other nutrient sources in order to support the growth of fastidious organisms are called __________ media.
general purpose, enriched
The ______________ ________ is the length of time it takes for a population of microorganisms to double in number.
generation time
Pathogenicity islands are typically associated with
genes encoding tRNA
The genetic information in DNA is divided into units called
genes.
Microbes such as Lactobacillus acidophilus colonize the human vagina by fermenting
glycogen
The chemotherapeutic agent much reach levels in the body that are _____________ the pathogen's MIC value if it is going to be effective.
greater than
With the E. coli trp operon where both repression and attenuation occur, the extent of regulation achieved by repression is _____________ the extent of regulation achieved by attenuation.
greater than
You discover a new transport system used by a newly discovered bacterial species. The sugars that are transported using this system phosphorylated as they enter the bacterial species cell. You would describe this transport system as a(n) ____________.
group translocation
Microbial __________ is an increase in cell constituents that may or may not be accompanied by an increase in cell number.
growth
Organisms that require high levels of sodium chloride in order to grow are called _______ organisms.
halophilic
External structures that are found in Archaea but not Bacteria are ______________.
hami
The reactivated form of chickenpox is called ___________.
herpes zoster
A major cause of blindness in the United States that results from the HSV 1 virus is ___________ __________.
herpetic keratitis
The incorporation of a single strand of donor DNA into a recipient DNA duplex so that the donor strand replaces one of the strands or the recipient duplex generates _________ DNA.
heteroduplex
A reciprocal exchange in which a pair of DNA with the same nucleotide sequence break and rejoin in a crossover is called _________ recombination.
homologous
Transfer of genes from one mature independent organism to another is called
horizontal gene transfer.
Listeria monocytogenes propels itself through mammalian host cells using
host cell actin and other cytoskeletal proteins.
Sulfonamides and other drugs that inhibit folic acid synthesis have a high therapeutic index because
humans do not synthesize folic acid but obtain it in their diets.
Molecules or regions of molecules that readily interact with water are said to be __________, whereas molecules or regions of molecules that are insoluble in water or do not readily interact with water are said to be hydrophobic.
hydrophilic
Actinomycetes form long filaments called ___________.
hyphae
Viruses that are polyhedrons with 20 sides are said to have _______ symmetry.
icosahedral
Two major types of symmetry found in viruses include
icosahedral and helical.
If autophosphorylation of CheA protein does not occur, then Escherichia coli cells must be
in a gradient of a chemoattractant.
When in the human body, Legionella pneumophila resides
in alveolar macrophages
Microbiota of the skin are most likely to be found
in association with oil and sweat glands
Poliovirus receptors are found
in nasopharynx, gut, and spinal cord anterior horn cells.
In eukaryotic cells, the enzymes involved in the tricarboxylic acid cycle (Kreb's cycle) are located
in the matrix of the mitochondria.
Mutations resulting from exposure to physical or chemical agents are called __________ mutations.
induced
Humans acquire typhoid fever by
ingesting water or food contaminated with feces.
All of the following are methods of prion disease transmission EXCEPT
inhalation (airborne)
Bacitracin
inhibits peptidoglycan synthesis.
When a repressor binds to the operator site on the DNA it normally
inhibits the initiation of transcription.
Vancomycin
inhibits the transpeptidation reaction in peptidoglycan biosynthesis.
The enzymes and electron carriers involved in electron transport and oxidative phosphorylation are located in the __________ membrane of the mitochondrion.
inner
Campylobacter jejuni is transmitted to humans by all of the following EXCEPT
insect vectors
Proteins that are embedded within the cytoplasmic membrane and not easily extracted are called _________ proteins.
integral
A new protein has been described that transports a growth factor across the plasma membrane. This protein is most likely a/an:
integral membrane protein.
A mutagen that inserts between the stacked bases of a DNA double helix, distorting the DNA to induce single-pair insertions or deletions is called a(n) __________ agent.
intercalating
An animal that is infected with a parasitic organism that can also infect humans is called a(n) ________ host.
intermediate
Protein filaments with a diameter of about 10 nm that are major components of the cytoskeleton are called
intermediate filaments
Methanogens are always engaged in relationships with other microbes because methane production requires
interspecies hydrogen transfer.
The unexpressed regions of split genes are called
introns.
The Pribnow box of E. coli
is centered approximately 10 bp upstream of the start site of transcription.
Mycoplasma pneumoniae
is one of the causes of atypical pneumonia
Isoniazid is a narrow-spectrum antibiotic that
is one of the few drugs effective against Mycobacterium tuberculosis.
Gamma radiation
is used to sterilize some food products.
Although penicillin inhibits peptidoglycan synthesis, bacterial cells will continue to grow normally in the presence of penicillin in a(n)______environment.
isotonic
The major reason why there are fewer antiprotozoan drugs than antimicrobial drugs is because
it is much more difficult to develop selectively toxic antiprotozoan drugs since protozoan cells are eukaryotic.
Agar is an excellent solidifying agent for microbiological media because
it is not degraded by most microorganisms and solid agar remains solid until the temperature is raised to 90C, and liquid agar remains liquid if the temperature is lowered to 45C are correct.
An insertion is distinguishable from other mobile genetic elements because
it is smallest.
Legionnaires' disease is so named because
it was first identified at a convention of the American Legion
Pasteurization is used to
kill any pathogens present and retard spoilage.
Sterilization involves _____________ all viable microorganisms.
killing OR removing
Archaeal cell walls
lack murein and D-amino acids.
On mRNA molecules, a nontranslated sequence called the ___________ usually precedes the initiation codon.
leader
The transcribed, but not translated, sequence that is immediately upstream of the region that encodes the functional product is called the __________ region.
leader
When antiseptics and disinfectants are compared, antiseptics are generally
less toxic.
Mutations that result in the death of an organism when expressed are called ____________ mutations.
lethal
Virulence may be measured experimentally at the host level by the __________ __________ __________, which measures the number of pathogens that kills 50% of an experimental group of hosts within a specified amount of time.
lethal dose 50
The toxic component of lipopolysaccharide is called _________.
lipid A
Gram-positive bacteria such as Propionibacterium acnes limit the growth of gram-negative bacteria and some fungi on the human skin by converting secreted _________ to compounds with antimicrobial activity.
lipids
Iatrogenic CJD has been transmitted by prion-contaminated by all of the following EXCEPT
liver transplants
A person who is infected with a potential pathogen fails to develop signs or symptoms of disease. This correlates with _________ initial microbial dose, _______ microbial lethality, and/or _______ replication rate of the pathogen.
low; high; low
The minimal lethal concentration (MLC) is the
lowest concentration of a drug that kills a particular pathogen.
Diphtheria toxin is produced only by strains of Corynebacterium diphtheriae that are infected with a particular bacteriophage. This is an example of
lysogenic conversion.
Diphtheria toxin is produced only by strains of Corynebacterium diphtheriae that areinfected with a particular bacteriophage. This is an example of
lysogenic conversion.
The production of cholera toxin by virulent strains of Vibrio cholera is dependent upon genes in a bacteriophage. This is an example of
lysogenic conversion.
The food vacuoles and phagocytic vacuoles are most similar to
lysosomes.
Nutrients that are used by bacteria in relatively large amounts are ____________.
macronutrients
Elements that are required in relatively large amounts by microorganisms are called
macronutrients.
Conjugative transposons
may be involved in the spread of antibiotic resistance in bacteria.
The filamentous bacteria that grow on the dorsal surface of certain polychaete worms
may provide the worm with protection from toxic metals.
Koplik's spots are small red lesions with a white center that form in the mouth and are associated with ____________.
measles
The disinfectant action of phenol and phenolic derivatives mainly is due to
membrane damage and protein denaturation.
Inflammation of the membranes around the brain or spinal cord is called _________________.
meningitis
A recipient cell that is temporarily diploid for a portion of the genome during the replacement process is called a(n) __________.
merozygote
Protein filaments with a diameter of 4-7 nm that play a role in cell movement and shape change are called
microfilaments
A filamentous organelle comprised of tubulins with a diameter of 25 nm is called
microtubule
The lowest concentration of an antibiotic that prevents growth is the
minimal inhibitory concentration (MIC).
A mutation that changes the amino acid sequence of the resulting protein by substitution is called a ___________ mutation.
missense
The higher the phenol coefficient value, the _______ effective the disinfectant under the test conditions.
more
Chemotaxis is a process by which bacteria
move toward an attractant or away from a repellent.
A branched network of hyphae formed by the Actinomycetes is called a ______________.
mycelium
Most microorganisms maintain their internal pH
near neutral (pH 7).
Localized areas of destruction occurring on plants that have been infected by a virus are referred to as __________ lesions.
necrotic
If a set of genes is repressed in the presence of the controlling substance, it is referred to as __________ control.
negative
Organisms that have their optimum growth pH between 5.5 and 9.0 are called ___________.
neutrophiles
A ________ mutation is one that causes premature termination of the synthesis of the protein product.
nonsense
Microorganisms commonly associated with the human body are traditionally referred to as the
normal microbial flora or the normal microbiota.
Acute viral gastroenteritis can be caused by the
norovirus and the rotavirus group
Bacteria have a region of the cytoplasm known as the __________, which is not bounded by a membrane but contains the chromosome.
nucleiod
Dental pathogens are called __________.
odontopathogens
Colds are common because
of the antigenic diversity of the rhinoviruses and the lack of long-lasting immunity.
Quorum sensing in Gram-positive bacteria generally involves the use of ________ as the external signaling molecules.
oligopeptides
Vector-borne transmission can be either external or internal. In external (mechanical) transmission, the pathogen is carried
on the body surface of a vector.
Genes whose expression (or abnormal expression) causes cancer are called
oncogenes.
Specialized transduction can be carried out by
only those temperate bacteriophages that integrate into the host chromosome.
The site on the DNA to which a repressor protein binds is the ___________.
operator
An __________ pathogen can cause disease in a host with impaired resistance.
opportunistic
When members of the normal microbiota of the human body become pathogenic and produce disease under certain circumstances, they are referred to as ______________ pathogens.
opportunistic
Membrane delimited intracellular structures that perform specific functions in cells are called
organelles
While examining the sequence if nucleotides in the replication region of bacterial DNA, you note an abundance of adenine and thymine base pairs. This leads you to conclude that this particular section of the DNA must be the
oriC site.
Each chromosome has one or more _________ site(s) where replication begins.
origin
The site at which replication of DNA starts in bacterial cells is known as the __________ of ___________.
origin, replication
The Golgi apparatus is responsible for the
packaging of materials for excretion
If a symbiont either harms or lives at the expense of another organism, the relationship is called
parasitism
Antibiotics that are given by injection are said to have a(n) ________ route of administration.
parenteral
The order of gene transfer in an Hfr F- mating is best represented by
part of the plasmid followed by the chromosome followed by the rest of the plasmid.
movement of molecules from an area of high concentration to an area of lower concentration without the participation of specific carrier molecules is called
passive diffusion.
A __________ is any disease-producing microorganism.
pathogen
Many bacteria are pathogenic because they carry large segments of DNA called ________ _______, which were acquired by horizontal gene transfer, and which carry genes responsible for virulence.
pathogenicity islands
The __________ is a complex structure or set of structures lying beneath the plasma membrane of many protozoa and some algae, which serves as a supportive mechanism for these cells.
pellicle
Proteins that are loosely associated with the cytoplasmic membrane are called ________ proteins.
peripheral
Flimmer filaments
permit flagella to pull rather than push the cell.
The process by which a cell imports large particles by enclosing them in vesicles pinched off from the plasma membrane is called
phagocytosis
The disinfectant screening method that is known as the __________ ____________ test, which is used to measure the potency of a disinfectant.
phenol coefficient
The disinfecting properties of Lysol, a common disinfectant, depend upon the presence of ______________.
phenolics
In two component regulatory systems, the response regulator typically receives a _________ from the sensor kinase when it has been activated.
phosphoryl group
Proteinacious projections from the surface of a bacterium that are used to mediate conjugation are called sex __________, whereas projections that mediate attachment to surfaces such as host cells are called __________.
pili; fimbriae
Most enveloped viruses use the host __________ membrane as their envelope source.
plasma
A _______ is a piece of extrachromsomal DNA that has its own replication origin.
plasmid
Small circular DNA molecules capable of replicating and containing genes that are useful but not necessary to the bacterium are called __________.
plasmids
Shrinkage of the plasma membrane away from the cell wall when the bacterium is placed in a hypertonic environment is called
plasmolysis.
Bacterial cells that are variable in shape are called
pleomorphic
If a set of genes is induced in the presence of the controlling substance, it is referred to as __________ control.
positive
In terms of global gene regulation, which of the following molecules is most similar to c-di-GMP and cAMP?
ppGpp
An example of microbial ________ is the ability of Vampirococcus to attach to the outer membrane of its prey and then secrete degradative enzymes that result in the release of the prey's cytoplasmic contents.
predation
Any organism that can cause disease in the host after direct interaction is a(n)
primary pathogen
Your brother mentions that several days ago he began to feel as if he was coming down with a cold, but now is no longer experiencing any signs or symptoms and feels fine. Having just studied the infectious disease process in your microbiology course, you immediately recognize that he is describing the ________ phase of illness.
prodormal
Staphylococcus epidermidis can be characterized by all of the following except that it
produces a yellow pigment
Human sweat has antimicrobial activity due to
production of an antimicrobial peptide called cathelicidins.
In __________, ribosomes can attach to the mRNA and begin translation even though transcription has not been completed.
prokaryotes
The coding sequence in the DNA of ____ is normally continuous; that is, it is not interrupted by noncoding sequences.
prokaryotes
A bacterial __________ is the nontranscribed region of the DNA to which RNA polymerase binds in order to initiate transcription.
promoter
The region at which the RNA polymerase binds is the __________ region.
promoter
When bound to the DNA, the repressor protein usually prevents attachment of the RNA polymerase to the __________.
promoter
A(n) ______ is a latent form of a virus genome that remains within the host without destroying it.
prophage
The function of the viral protein coat is to
protect the viral genetic material and aid in the transfer of the viral genetic material between host cells.
While standard two-component regulatory systems typically act to control gene transcription, phosphorelay systems can act either to control gene transcription or to control _________.
protein activity
All of the following processes are located within a membranous structure EXCEPT
protein synthesis (translation).
The power used by most bacterial flagellar motors is produced by
proton motive force (PMF).
Microbial strains that can grow on minimal medium are called ___________.
prototrophs
A newly discovered unicellular microbe has a nucleus containing linear chromosomes and surrounded by a membrane. It has mitochondria, 80s ribosomes, and is covered by cilia. There is no cell wall external to the plasma membrane. This organism most likely would be a/an
protozoan.
All of the following are appropriate strategies for overcoming drug resistance in bacteria except
prudent use of antibiotics when treating viral infections.
A peptidoglycan-like polymer found in the cell walls of some Archaea is called ________.
pseudomurein
Organisms that grow well at 0C and have optimum growth temperatures of 15C or lower are called
psychrophiles.
Organisms that grow at 0C and have a maximum growth temperature of 35C are called
psychrotrophs.
Sulfonamides inhibit the production of folic acid and, therefore, inhibit the synthesis of __________.
purines and pyrimidines
When RNA polymerase catalyzes the addition of a nucleotide to a growing mRNA chain, a byproduct of this reaction is
pyrophosphate.
Two amino acids that are found in some proteins due to exceptions in the universal genetic code are
pyrrolysine and selenocysteine.
Lethal mutations can be maintained in diploid organisms of they are
recessive.
The process in which one or more nucleic acid molecules are rearranged or combined to produce a new nucleotide sequence is called
recombination.
Acyclovir is the drug used to treat genital herpes; it
reduces the healing time.
The loss of genetic information no longer needed for an intracellular existence by an obligate parasite is called genomic _____________.
reduction
Which of the following environmental factors generally do(es) not have an impact on the efficiency of an antimicrobial agent?
refractive index
A collection of genes or operons controlled by a common regulatory protein is called a(n) ___________.
regulon
Endocytic events
remove membrane from the cell surface.
The __________ is a group of proteins needed for DNA synthesis that assembles at the origin of replication.
replisome
When there is no arabinose available in the environment, the AraC protein acts as a(n) ________ for the E. coli ara operon.
repressor
Plasmids that have genes that decrease bacterial susceptibility to antibiotics are called __________ factors.
resistance
In influenza virus, antigenic shift
results from reassortment of genomes when two different strains of flu viruses infect the same cell and can result in major epidemics or pandemics.
Adult T-cell leukemia is thought to be caused by
retroviruses.
Joseph Lister
revolutionized surgery by introducing phenol as a disinfectant.
The nuclear organizer is a part of a specific chromosome that directs the synthesis of
ribosomal RNA (rRNA)
Proteins are synthesized on structures called
ribosomes.
Endoplasmic reticulum (ER) with many ribosomes attached is called ________ ER, whereas endoplasmic reticulum that is mostly devoid of ribosomes is called ________.
rough, smooth
German measles is caused by the ________ virus.
rubella
Neisseria gonorrhoeae may sometimes cause
salpingitis and opthalmia neonatorum
The reduction of the microbial population to levels that are considered safe by public health standards is called
sanitization.
A __________ genome exists as several separate, nonidentical molecules that may be packaged together or separately.
segmented
A growth medium that favors the growth of some microorganisms but inhibits the growth of other microorganisms is a __________ medium.
selective
Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes). Among the halophiles, mannitol fermenters will produce acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol nonfermenter and a nonhalophilic mannitol nonfermenter. In this case, the medium is acting as a _______ medium.
selective
Viral capsids are generally constructed without any outside aid once the subunits have been synthesized. This process is called
self-assembly.
When a DNA molecule is replicated, the daughter molecules contain one strand of parental DNA and one strand of newly synthesized DNA; this is called _______________ replication.
semiconservative
Chemotherapeutic agents that are chemically modified natural products of microorganisms are most specifically referred to as ______________.
semisynthetic drugs
The sensing of starvation that leads to sporulation in Bacillus subtilis is accomplished by a____________.
sensor kinase
The process of forming a cross wall between two daughter cells is known as __________.
septation
Bacteria that live attached to surfaces are described as __________, whereas bacteria that are free-living, floating with a fluid environment are described as _____________.
sessile; planktonic
Many bacteria facilitate the uptake of iron by secreting low molecular weight molecules, called __________, to form complexes with the iron that can then be readily transported into the cell.
siderophores
A _____________ mutation does not alter the amino acid sequence of the resulting protein.
silent
A reverse transcribing DNA virus that wants to replicate its genome must first convert the dsDNA to __________ before using that to create copies of the dsDNA genome.
single strand RNA
Q fever is apt to occur in epidemic form among ________.
slaughterhouse workers
A __________ layer consists of diffuse unorganized polysaccharide material that lies outside the cell wall and is easily removed.
slime
The rickettsial parasite Wolbachia pipientis can
sometimes alter the sex of an infected wasp.
The genus of bacteria that undergoes cell division in random planes, forming grapelike clusters of round bacteria, are the _______________.
staphylococci or staphylococcus
A(n) _________ is a chemical that can be used to sterilize materials.
sterilant
The destruction or removal of all viable organisms is called
sterilization.
In addition to inhibiting the transpeptidation reaction in cell wall synthesis, penicillins may also destroy bacteria by
stimulating proteins to form holes in the plasma membrane.
The formation of carbohydrate (CO2 fixation) in the dark reaction of photosynthesis, takes place in the
stroma
Over twisting or under twisting of helical DNA generates
supercoils.
A close physical relationship between two different species that may or may not be beneficial is called __________.
symbiosis
Any microorganism that spends a portion of its life associated with another organism of a different species is engaged in
symbiosis
Transport of two different substances can be linked. If the transport is in the same direction it is called ___________; if the transport is in opposite directions it is called ___________.
symport, antiport
Chemotherapeutic agents that are artificially produced are most specifically referred to as _______________.
synthetic drugs
The term __________ is used to describe a mutually beneficial association in which the growth of an organism is dependent on one or more growth factors, nutrients, or substrates provided by another organism in the same vicinity.
syntrophism
If the product of a functional gene is not a protein, what other product(s) might be encoded by the gene?
tRNA and rRNA
The strand of DNA for a particular gene that is copied by the RNA polymerase to form mRNA is called the _____strand.
template
Square planar arrangement of cells that forms when round bacteria remain attached to each other during reproduction are called
tetrads.
The sensor kinase for the OmpF: OmpC two-component regulatory system is
the EnvZ protein.
In commensalism
the host and commensal can be separated and remain viable.
The activity of adenyl cyclase is influenced by
the phosphotransferase system
The limitation on microbial growth rate at high nutrient levels is/are
the saturation of the transport proteins for nutrient uptake.
The drug level required for the clinical treatment of a particular infection is called the
therapeutic dose.
The ratio of toxic dose to therapeutic dose is called the
therapeutic index.
The use of bacteriophage to treat human infections is referred to as phage ___________.
therapy
Organisms that grow near deep sea volcanic vents are likely to be
thermophilic.
In order to add a single amino acid to a growing polypeptide chain, a total of __________ molecules or ATP or GTP are utilized.
three
The E. coli lac operon has _________ operator sequences.
three
The genetic code is translated in groups of __________ bases.
three
The light reactions of photosynthesis , which form ATP and NADPH, take place in the
thylakoid membrane.
The inner membrane system of chloroplasts consists of flattened sacs called _______ that form stacks called _______.
thylakoids, grana
The vector for Rocky Mountain spotted fever is the ___________.
tick
The capacity of an organism to produce a toxin is called __________.
toxigenicity
Exotoxins can be denatured by iodine to form __________ which are useful in vaccines.
toxoids
Chlamydia trachomatis causes
trachoma and nongonococcal urethritis
Messenger RNA molecules have a nontranslated sequence called the ___________, which is located downstream of the termination codon.
trailer
The process by which the base sequence of all or a portion of a DNA molecule is used to direct the synthesis of an RNA molecule is called
transcription.
As the result of exposure to a mutagen, cytosine is substituted for thymine in one strand of DNA. Upon subsequent DNA replication, one of the daughter cells will have a GC pair in this position instead of an AT pair. This is called a(n) __________ mutation.
transition
The process by which the base sequence of an RNA molecule is used to direct the synthesis of a protein is called
translation
In general, riboswitches regulate __________________ in Gram-negative bacteria such as Escherichia and ____________ in Gram-positive bacteria such as Bacillus.
translation; transcription
During _________ proteins are moved from the cytoplasm to the membrane or periplasmic space, while during _________ proteins are moved from the cytoplasm to the external environment.
translocation, secretion
The __________ reaction sequentially links adjacent amino acids into the growing polypeptide chain.
transpeptidation
The specialized structure in a tube worm in which endosymbiotic, chemolithotrophic bacteria live is called a(n) ___________.
trophosome
A strain of Vibrio cholerae lacking the cholera toxin gene (ctxAB) would be
unable to cause watery diarrhea.
In mismatch repair on newly replicated DNA, enzymes distinguish between old and newly replicated DNA strands based on the fact that newly replicated DNA strands are ________-methylated relative to older DNA.
under or less
The membranes of psychrophilic bacteria have relatively high levels of ______ fatty acids, which allow them to remain semifluid at cold temperatures.
unsaturated
If Escherichia coli is cultured in broth containing both glucose and lactose, it
uses glucose preferentially until the supply is exhausted, then uses lactose.
Chickenpox is caused by the ________ virus.
varicella
A(n) ________ is an organism that transfers pathogens from one host to another
vector
One hypothesis about the decline in cell numbers during death phase is that the cells aren't all dying but instead remain alive but unable to grow when cultured, at least temporarily. These are known as
viable but nonculturable cells.
The term to describe bacteria that are shaped like curved rods is
vibrio.
Large-scale screening of blood for the hepatitis B virus uses an assay designed to detect
viral surface antigens.
In those cases of pneumonia for which no cause is determined by laboratory findings, __________ pneumonia can be assumed if ___________ pneumonia has been ruled out.
viral; mycoplasmal
A complete virus particle is called a
virion.
