McGraw-Hill Microbiology Chapter 8-11 Combined
Two methods used to identify mutants in a culture are ______ and ______ selection. direct; indirect plus; minus excision; photoreactivation forward; reverse
direct; indirect
*Select all that apply* The polymerase chain reaction (PCR) is used in ______. sequencing target proteins disease diagnosis amplifying target DNA
disease diagnosis amplifying target DNA
Phage typing is used to ______.
distinguish different bacterial strains
Which of the following taxonomic designations is inclusive of all the others listed?
domain
Wolbachia pipientis can be found inside parasitic worms that cause ______.
elephantiasis river blindness
The _________ produced by the genus Clostridium have the ability to survive harsh environmental conditions that can commonly kill the vegetative bacterial cells.
endospores
Beggiatoa and Thiothrix species are examples of ______.
filamentous sulfur oxidizers
In 1969, R. H. Whittaker proposed a system of _______ based largely on _______.
five kingdoms; morphological differences
*Select all that apply* Which of the following are caused by chemical mutagens? frameshift mutations double stranded breaks thymine dimers base substitutions
frameshift mutations base substitutions
There are two types of transduction: ____________ , which transfers any genes of the donor cell, and ___________ , which transfers only a few specific genes.
generalized specialized
Methanogens are organisms that ______.
generate methane obtain energy by oxidizing hydrogen gas use CO2 as a terminal electron acceptor
__________ engineering has been used to produce vaccines, pharmaceutical proteins, transgenic plants and animals, and DNA.
genetic
Biotechnology is generally associated with __________ _____________ , the process of deliberately altering an organisms genetic makeup using in vitro techniques.
genetic engineering
During transduction, donor DNA is injected into a recipient cell by a phage. This DNA integrates into the recipient's chromosome by ______ _______.
homologous recombination
During horizontal gene transfer in bacteria, the transferred donor DNA may be integrated into the recipient's genome via a process called ______. heterologous conversion chromatid exchange nonhomologous end joining homologous recombination
homologous recombination
The most likely place to isolate the bacterium that naturally produces Taq polymerase is _______. plants humans soil hot vents arctic ice
hot vents
A(n) __________ mutation is a base substitution that changes the codon to one that specifies a different amino acid.
missense
DNA in the environment that is not contained within a cell or virus is called ________ DNA.
naked
Many cyanobacteria can convert nitrogen gas (N2) to ammonia, which is a process called ______.
nitrogen fixation
A base substitution that leads to the creation of a stop codon is called a(n) ________ mutation.
nonsense
An organism that cannot reproduce outside of a host cell is termed an _______ _______ parasite.
obligate intracellular
A strain is ______.
one of a group of related isolates within a species
(LETTER C IN PHOTO) The structure connecting these two cells is called an F _______ and is formed during the mechanism of DNA transfer called _______.
pilus conjugation
Which of the following can distinguish members of the genus Staphylococcus from Streptococcus, Enterococcus, and Lactococcus species?
presence of the enzyme catalase
Propionibacterium species produce _______ acid as their major fermentation end product.
propionic
Gel electrophoresis may be used to separate DNA, RNA, or ______ according to their size. proteins carbohydrates lipids
proteins
An organism that does not require growth factors is called a(n)__________.
prototroph
Base substitutions are more common in aerobic vs. anaerobic environments because of the production of ______ under aerobic conditions. ATP reactive oxygen species DNA polymerase guanine nucleotides
reactive oxygen species
Mutation rates are low because proofreading and _________ mechanisms fix altered or damaged DNA before it can be passed to progeny.
repair (or mismatch repair, or DNA repair)
Plating bacteria in duplicate patterns on both a nutrient agar plate and a glucose-salts agar plate is an example of _______ plating.
replica
By definition, obligate intracellular parasites cannot ______.
replicate outside of a host cell
Thymine dimers can kill cells if left unrepaired, as they cause kinks in DNA that interfere with the processes of _________ and __________.
replication transcription
Reverse transcriptase is naturally produced by _______. rhabdoviruses Mycoplasma species retroviruses Mycobacterium species
retroviruses
The enzyme that synthesizes DNA using an RNA template is called ___________ ____________.
reverse transcriptase
The enzyme ______ is used to convert mature, eukaryotic mRNA into a strand of complementary DNA. phosphodiesterase DNA ligase DNA polymerase reverse transcriptase
reverse transcriptase
To differentiate species in the family Enterobacteriaceae, a microbiologist could use which of the following methods?
serological tests biochemical tests
All of the following are examples of biochemical tests EXCEPT one. Which?
serology
The species designation gives a formal taxonomic status to a group of related isolates, or ______.
strains
Green sulfur bacteria are ______.
strict anaerobes
Base ______ mutations occur when an incorrect nucleotide is incorporated in place of another during DNA synthesis. translocation insertion substitution deletion
substitution
The most common type of mutation is base __________, where an incorrect nucleotide is incorporated during DNA replication.
substitution
In MALDI-TOF mass spectrometry, a protein profile is generated as the detector records the ionized molecules that arrive through a flight tube. The "time of flight" is based on ______.
the mass of the ions, with smaller ions arriving faster
Segments of DNA that can move to new positions within the genome of a single cell are called ____________.
transposons
___________ are DNA segments that increase the rate of mutations by inserting themselves into genes and inactivating them.
transposons
In this figure of sugar fermentation, tube D is an uninoculated control. Match the other three tubes to the correct result.
tube A - negative test tube B- positive test with gas production tube C- positive test with no gas production
Bacteria that oxidize sulfur are Gram-negative rods or spirals that ______.
use sulfur compounds as an energy source and oxygen as a terminal electron acceptor
What is the best definition of a signature sequence?
A sequence in rRNA that characterizes either a certain species or a group of related organisms.
Which of the following is an example where a stain would be strongly suggestive of a particular pathogen?
Acid-fast stain of sputum from a respiratory infection suggestive of Mycobacterium tuberculosis.
Determining the phylogeny, or evolutionary relatedness, of members of which of the following groups would likely be the least difficult?
Animals
The cell walls of members of the domain _________ typically contain a polymer called peptidoglycan.
Bacteria
______ species are Gram-negative, strictly anaerobic, make up about a third of the bacteria in fecal matter in humans, and are associated with abscesses and bloodstream infections.
Bacteroides
What is the most important reference for taxonomic descriptions of bacteria?
Bergey's Manual of Systematic Bacteriology
A membrane-bound nucleus is only found in organisms that belong to the domain
Eukarya
When an excision errors produces a plasmid containing both chromosomal and F plasmid DNA, the resulting plasmid is called a(n) ________ plasmid.
F'
True or false: Organisms cannot be identified unless they can first be cultivated.
False
he base ratio of an organism is usually expressed as the percent of guanine plus cytosine, which is called the
GC
Assuming all molecules are equal in size, a DNA with a higher ______ will melt at a higher temperature.
GC content
Which of the following could NOT be the recognition site of a restriction enzyme? GAATTC CTTAAG GGATCC CCTAGG GCTTGC CGAACG CTGCAG GACGTC ATCGAT TAGCTA
GCTTGC CGAACG
Which of the following terms describes the sequence of nucleotides (genetic makeup) of an organism or a cell? - Phenotype - Serotype - Genotype - Haplotype
Genotype
In __________ gene transfer, DNA moves from one organism to another, while in__________ gene transfer, DNA is passed from a parent cell to its progeny.
Horizontal - Vertical
_________ mutations are genetic changes caused by factors from outside of the cell such as radiation or chemicals.
Induced
_________ agents insert themselves between adjacent base pairs in a DNA strand, increasing the rate of frameshift mutations.
Intercalating
Medically-significant members of the genus Neisseria include which of the following?
N. gonorrhoaeae N. meningitidis
*Select all that apply* The distortion of DNA by thymine dimers directly blocks which of the following cellular processes? Translation Respiration Replication Transcription
Replication Transcription
Which of the following is considered the most reliable indicator of evolutionary relatedness in prokaryotes?
Sequences of ribosomal components
Which of the following are characteristics of the genus Propionibacterium?
They can ferment lactic acid. They are Gram-positive.
_________ _________ are a type of radiation that can cause single and double stranded breaks in a DNA strand.
X rays
Restriction enzymes are naturally produced by ______. fungi protozoa viruses bacteria
bacteria
Species of Rickettsia and Ehrlichia are transmitted ______.
by blood-sucking arthropods
Sulfur-oxidizing bacteria ______.
can use hydrogen sulfide or thiosulfate as an energy source can sometimes grow in filaments
The cells of species in the genus Neisseria are ______.
cocci Gram-negative typically found in pairs
The ends shown here are generated by the action of a restriction enzyme. They are called _______ ends. cohesive blunt adhesive conserved
cohesive
A plasmid that can directs its own transfer from donor to recipient cells is called a(n) _________.
conjugative
Deduced amino acid sequences from ______ are now used as a basis for determining relatedness.
whole and partial genome sequences
The native or _________ _______ strain describes cells that carry non-mutated DNA.
wild type
Chemical mutagens that squeeze between base pairs and induce frameshift mutations are called ______. thymine dimers alkylating agents intercalating agents base analogs
intercalating agents
Species of Campylobacter and Helicobacter are ______.
microaerophilic curved, Gram-negative rods
Which type of DNA repair is shown in this illustration? thymine dimer repair photoreactivation mismatch repair modified nucleobase repair
mismatch repair
A base substitution that results in a change in the amino acid encoded is called a(n) ______ mutation.
missense
Consider a base substitution mutation that occurs in a codon that specifies the amino acid tryptophan. If it leads to a different amino acid, the mutation is called _________ mutation, and if the resultant codon is a stop codon, then the mutation is termed a(n) ________ mutation.
missense nonsense
A _________ is an agent that induces changes in DNA.
mutagen
A group of strains that have cell surface antigens different from other strains is called a
serovar
Hydrogen-oxidizing bacteria such as Aquifex and Hydrogenobacter are ______.
obligate chemolithotrophs Gram-negative thermophilic
A(n)__________ mutation occurs if a single base pair is changed during DNA synthesis.
point
When a DNA fragment is inserted into a vector, this results in a(n) ______ molecule. library vector-less recombinant insert
recombinant
When two or more DNA molecules are linked together using in vitro methods, the resulting molecule is called ___________ DNA.
recombinant
Biotechnology now uses ______ to genetically engineer organisms to give them useful traits. traditional genetic screens recombinant DNA techniques
recombinant DNA techniques
When horizontal gene transfer occurs between a donor and recipient cells, the resulting cells are called ________.
recombinants
Unicellular sulfur oxidizers can be used to ______.
recover metals prevent acid rain
This graph, which charts the behavior of a double-stranded DNA molecule exposed to a range of high temperatures, illustrates the temperature at which the molecule denatures, or ________ __________ curve.
DNA melting
During repair of oxidized guanine, which enzyme removes the damaged nucleobase from the sugar-phosphate backbone? DNA glycosylase RNA polymerase DNA ligase DNA polymerase helicase
DNA glycosylase
Bordetella species are ______.
small aerobic Gram-negative coccobacilli nutritionally fastidious
he 16S rRNA molecule is part of the _______ subunit of the prokaryotic ribosome, and is equivalent to the ______ rRNA of eukaryotes.
small; 18S
A group of closely related strains or individuals comprises a taxonomic category called
species
The basic taxonomic unit is the
species
Members of the genera Treponema and Borrelia are characterized by their corkscrew shape and endoflagella, thus making them ______.
spirochetes
Mutations that arise naturally during cellular metabolism, and not as a result of exposure to mutation-causing agents, are called _________ mutations.
spontaneous
When DNA is transferred from an Hfr cell to a recipient cell, the recipient _______. becomes an F+ cell becomes an Hfr cell stays an F- cell becomes a competent cell
stays an F- cell
Which of the following is a beneficial characteristic of some cyanobacteria?
Filamentous cyanobacteria can prevent soil erosion in cold desert areas such as the Colorado Plateau.
Which of the following mutations frequently results in the production of a shortened and non-functional protein because a different set of codons is translated? Frameshift Base substitution Nonsense Missense Silent Point
Frameshift
Which of the following mutations frequently results in the production of a shortened and non-functional protein because a different set of codons is translated? Nonsense Base substitution Frameshift Silent Point Missense
Frameshift
For the scientific name Staphylococcus aureus, Staphylococcus has which of the following designations?
Genus
Which of the following describe characteristics of members of the genus Vibrio?
Gram-negative straight or curved rods Typically found in marine environments
A base substitution that results in a codon that still codes for the wild type amino acid is called a(n) ______ mutation.
synonymous
During photosynthesis, anoxygenic phototrophs use _______ as a source of electrons to make reducing power.
H2S
Starting with the most general and ending with the most specific, which is the correct order for taxonomic units?
Kingdom, phylum, class, order, family, genus, species
Anoxygenic phototrophs typically live in which of the following environments?
Lakes Upper layers of mud Bogs
You isolate Gram-positive cocci that are obligately aerobic. They are salt-tolerant and form colonies that have a yellow pigment. This organism is most likely a member of the genus ______.
Micrococcus
A(n)___________ is a change in the nucleotide sequence of DNA that is passed on to daughter cells.
Mutation
The enzyme complex that catalyzes nitrogen fixation is called
Nitrogenase
*Select all that apply* Which of the following types of radiation are mutagenic? Ultraviolet rays Infrared rays X-rays
Ultraviolet rays X-rays
Genera of the family Enterobacteriaceae include all the following EXCEPT one. Which?
Vibrio
How do aerobic chemoorganotrophs obtain their energy?
by oxidizing organic compounds by using O2 as a terminal electron acceptor
*Select all that apply* The consequences of not repairing damaged DNA in cells include ______. cells that have fewer mutations cancer (in animals) increased activity of RNA polymerase cell death
cancer (in animals) cell death
The _______ test detects the ability of the organism to produce an enzyme that breaks down hydrogen peroxide to form O2 and water.
catalase
Coxiella burnetti ______.
causes Q fever can form spore-like small cell variants (SCVs) that survive well in the environment
All of the following information can generally be determined from microscopic examination of a microorganism EXCEPT ______.
definitively determining the genus and species of the microorganism
_______ mutations are generally the most harmful to cells because they change all of the codons downstream of the mutation.
frameshift
After new virus particles have assembled in the bacterial host cell, they are usually ______. stored inside the cell for a later time released as a result of host cell lysis destroyed by the bacterial immune system integrated into the structure of the bacterial cell wall
released as a result of host cell lysis
Members of the genus Vibrio ______.
include pathogens such as V. cholerae and V. vulnificus
An auxotroph can be isolated from a prototrophic parent strain by ______ selection. direct indirect differential degenerate
indirect
Replica plating is used in ______ selection to transfer an identical pattern of bacterial cells to both a nutrient agar and a glucose-salts agar plate. indirect differential direct degenerate
indirect
Wolbachia pipientis ______.
infects arthropods and parasitic worms and is transmitted maternally
Members of Chloroflexus grow in hot springs, which makes them ______.
thermophilic
All of the following are characteristics shared by both Helicobacter and Campylobacter EXCEPT ______.
they cause diarrheal disease in humans
In generalized transduction, donor DNA is mistakenly packaged into a phage coat, forming a __________ particle.
transducing
Humans infected with Helicobacter pylori may develop peptic
ulcer
How do obligate aerobes obtain energy?
using respiration only
Pulse Net, Genome Trakr, and Global Microbial Identifier are examples of surveillance networks and programs that use ___________ ___________ sequence (WGS) data to help track infectious disease outbreaks both nationally and around the world.
whole genome
*Select all that apply* What is the importance of the polymerase chain reaction (PCR)? It can be used to cut DNA into defined fragments. It can be used to detect target DNA in a sample. It can be used to increase the amount of a select region of DNA in a sample.
It can be used to detect target DNA in a sample. It can be used to increase the amount of a select region of DNA in a sample.
Most methods that use nucleic acid probes to detect DNA sequences rely on a step that increases the amount of DNA in the sample. How can this be accomplished?
A preliminary in vitro DNA amplification step can be performed. The specimen can be inoculated onto an agar medium so that each cell multiplies, forming a colony.
Which of the following scenarios would be least likely to require a nucleic acid amplification test?
A researcher trying to identify a flask of E. coli among a dozen mislabeled flasks of other microbes of medical importance growing in lab.
In humans, two of the genes associated with the development breast cancer encode enzymes involved in _________. mutagenesis DNA repair cell death DNA damage
DNA repair
A series of alternative choices that lead to the identification of an organism is referred to as a(n)
Dichotomous
media are designed to reveal specific colony characteristics that can help in the initial identification of bacteria in clinical samples.
Differential
*Select all that apply* X rays can cause which types of damage to a DNA molecule? Thymine dimer formation Double stranded breaks Nucleobase alterations Single stranded breaks
Double stranded breaks Nucleobase alterations Single stranded breaks
In the most thoroughly studied example of bacterial conjugation, the term _______ designates a donor cell with an F plasmid, whereas those cells who lack the F plasmid are termed _________.
F+ F-
True or false: Vertical gene transfer is the transfer of genes from one organism to another in a population, while horizontal gene transfer is the transfer of genes from parent cell to progeny.
False
True or false: Alkylating agents typically cause frameshift mutations.
False
True or false: Only fragments of DNA from the same organism can be joined together to make a recombinant DNA molecule.
False
True or false: The three-domain system has always been used as the standard classification system for organisms.
False
True or false: Ultraviolet rays are chemical mutagens.
False
A technique that uses probes that can bind 16S rRNA and does not require an amplification step because numerous copies of rRNA are present in multiplying cells is called which of the following?
Fluorescence in situ hybridization (FISH)
Which of the following terms describes the sequence of nucleotides (genetic makeup) of an organism or a cell? - Serotype - Phenotype - Haplotype - Genotype
Genotype
Bifidobacterium species are ______.
Gram-positive, irregular rod-shaped anaerobes part of the intestinal microbiota
Aside from green and purple bacteria, Gram-positive endospore forming rods of the genus ______ are also anoxygenic phototrophs.
Heliobacterium
This figure depicts the interconversion between an F+ cell and a(n) _________ cell.
Hfr
Why are sequence comparisons of the DNA coding for ribosomal RNA (rRNA) so useful in placing organisms on a phylogenetic tree?
Horizontal transfer of rDNA is rare Regions of rDNA are highly conserved. rDNA is present in all organisms
Match the Roman numeral with the correct serotype designation.
I- H antigen II- K antigen III- O antigen
Which of the following is NOT a medically-significant member of the genus Mycoplasma?
Mycoplasma leprae
Which process requires visible light to repair DNA damage caused by ultraviolet light? Photolysis Excision repair Photoreactivation
Photoreactivation
*Select all that apply* Which of the following are replicons? Plasmid Chromosome fragment Chromosome
Plasmid Chromosome
Describe some growth conditions or characteristics that enable Pseudomonas aeruginosa to be a problem in hospital environments
Resistant to antibiotics Ability to grow in nutrient-poor environments Resistant to disinfectants
Why are ribosomal components (ribosomal RNA and ribosomal proteins) considered reliable indicators of evolutionary relatedness?
Ribosomes are present in all organisms. Ribosomes perform crucial and functionally constant tasks. Ribosomal genes are not commonly horizontally transferred.
Which of the following is a limitation of using ribosomal DNA sequence analysis for determining the phylogeny of organisms?
Sequence analysis of 16s rDNA is often unreliable for distinguishing closely related species.
What process involves determining the order of nucleotides in a fragment of DNA? Sequencing Hybridization Electrophoresis Mapping
Sequencing
testing uses antibodies to detect characteristic proteins or polysaccharides that make up microorganisms.
Serological
The designation O157:H7 of E. coli is an example of which of the following?
Serological typing
What is the basic unit of taxonomic classification?
Species
Nomenclature
System of assigning names to organisms
*Select all that apply* Which of the following are characteristics of recombinants? They are genetically identical to their parent strain. They have multiple chromosomes. The have properties of both donor and recipient cells. They result from horizontal gene transfer.
The have properties of both donor and recipient cells. They result from horizontal gene transfer.
Consider the four sugar fermentation tubes. The left tube is a negative control, and on the right is an uninoculated tube. What does the tube second from the left indicate?
The organism fermented the provided sugar to yield acid and gas.
DNase is added to a mixture of donor DNA and recipient. If the donor DNA is naked, what will happen? The DNase will degrade the recipient's chromosome. The recipient will be transformed by the naked DNA. The recipient will be unable to acquire that DNA via transformation.
The recipient will be unable to acquire that DNA via transformation.
Base ______ structurally resemble nucleobases and can be mistakenly incorporated into nucleotides and then into DNA. pairs analogs adapters donors
analogs
An atmosphere that lacks O2 is called
anoxic or anaerobic
A major advantage of commercial variations of traditional biochemical tests such as API strip tests is that they ______.
are less labor-intensive than traditional biochemical tests
In higher organisms such as plants and animals, the basic taxonomic unit of species is considered to be organisms that ______.
are morphologically similar can interbreed to produce fertile offspring
A group of strains that have a characteristic biochemical pattern is called a ______, or biotype.
biovar
Cyanobacteria as a group are capable of ______.
both photosynthesis and nitrogen fixation
During bacterial conjugation, synthesis of a new strand of F plasmid DNA occurs in _________. neither the donor nor the recipient both the donor and recipient either the donor or the recipient, but not both the recipient only the donor only
both the donor and recipient
The urea ________ test (UBT) is a biochemical test done on a patient to determine whether he or she is infected with Helicobacter pylori, a common cause of stomach ulcers.
breath
According to the rules of nomenclature, the name of a bacterium or archaeon ______.
can honor a scientist can reflect the habitat of the organism needs to include a Latin suffix
As a group, anaerobic chemoorganotrophs ______.
can obtain energy via fermentation produce ATP via substrate level phosphorylation
Unlike standard DNA polymerases, the DNA polymerase used in SOS repair ______. can proofread DNA can call on other DNA polymerases for help can synthesize DNA even in very damaged regions
can synthesize DNA even in very damaged regions
Choose the properties that are representative of members of the domain Eukarya.
cell membranes that contain fatty acids linked to glycerol by an ester linkage membrane-bound nucleus introns
The earliest oxygenic phototrophs probably belonged to a group of bacteria called the
cyanobacteria
Heterocysts are structures found in ______ and are involved in _______.
cyanobacteria; nitrogen fixation
Unlike in other anoxygenic phototrophs, in purple bacteria, the components of the photosynthetic apparatus are all located in the cell's ________ membranes.
cytoplasmic
Bacteria lack the ability to remove introns from precursor RNA. Thus, for cloning purposes it may be necessary to ______. use different promoters generate cDNA from mRNA turn cDNA into mRNA use the DNA after it has been processed use the DNA directly
generate cDNA from mRNA
The ___________ is the nucleotide sequence in the DNA of a cell or an organism.
genotype or genome
The ______ stain distinguishes between the two major groups of bacteria, an essential first step in the identification process.
gram
Members of the Gram-negative genera Aquifex and Hydrogenobacter are hydrogen-oxidizing bacteria. An example of their metabolism involves using ______.
hydrogen as a source of energy and oxygen as a terminal electron acceptor, forming water
When sulfur is used as a terminal electron acceptor in the metabolism of an organic compound, the products are carbon dioxide and ______.
hydrogen sulfide
Most vectors have a second genetic marker that is made non-functional if an insert is in the multiple-cloning site. This disruption of the marker's function is called ______. recombinant DNA knockout mutant selective gene deletion insertional inactivation
insertional inactivation
When the sticky ends of two DNA fragments anneal, the enzyme DNA _________ can then form a covalent bond between the fragments to create a recombinant DNA molecule.
ligase
Filamentous anoxygenic phototrophic bacteria ______.
may possess chlorosomes exhibit gliding motility
During DNA replication, the template strand can be distinguished from the newly synthesized strand by the presence of _________ groups on certain nucleobases. This is very important for mismatch repair.
methyl
The enzymes of the mismatch DNA repair mechanism distinguish between the template strand and the newly synthesized strand by the presence of a(n) ______ group on certain nucleobases of the template strand. hydroxyl carboxyl amino phosphate methyl
methyl
If the GC content of two organisms is 67%, the organisms ______.
might be related
Although diagrams describing applications of biotechnology often only show one or a few molecules of DNA, in reality ______. these molecules are much larger than they appear millions of molecules are involved
millions of molecules are involved
Sometimes DNA polymerase adds the wrong nucleotide to the growing chain. If proofreading does not fix the error, then it is usually fixed by a mechanism called ________ repair.
mismatch
*Select all that apply* Which of the following are possible outcomes of a base substitution? missense mutation thymine dimer mutation synonymous mutation frameshift mutation nonsense mutation
missense mutation synonymous mutation nonsense mutation
An organism that has a mutation is called a________
mutant
Which type of DNA repair is shown in this figure? nucleotide excision repair base excision repair proofreading mismatch repair photoreactivation
nucleotide excision repair
The three-domain system of classification is based upon comparisons of ______ made by Carl Woese and colleagues in the late 1970s.
nucleotide sequences of ribosomal RNA
Aerobic chemolithotrophs obtain energy by oxidizing reduced inorganic chemicals, using ________ as a terminal electron acceptor.
oxygen, oxygen gas, or O2
A bacterial virus is known as a(n) _______. elementary body prion retrovirus bacteriovirus phage
phage
The _______ is the observed characteristics of an organism.
phenotype
Microscopic morphology, culture characteristics, and fatty acid analysis are all examples of ______ characteristics used to identify prokaryotes.
phenotypic
The repair of thymine dimers by enzymes that break the covalent bonds between the dimers is called ______ repair. photoreactivation excision sos proofreading mismatch
photoreactivation
Cyanobacteria are a group of _______ bacteria.
photosynthetic Gram-negative
The evolutionary relatedness of organisms is called
phylogeny
When describing conjugation in Gram-negative bacteria, a donor cell with an F ______ is considered F+, while that without this structure are termed F-. fimbria cilium flagellum chromosome plasmid
plasmid
Members of the genus Corynebacterium are Gram-positive rods that exhibit a variety of shapes. This difference in shape is referred to as being ______.
pleomorphic
Nitrogen fixation, or the process of converting nitrogen gas (N2) into ammonia, is an exclusive ability of ______.
prokaryotes
Repair of nucleotide incorporation errors during the process of DNA replication is accomplished by _________ by DNA polymerase and by __________ repair.
proofreading mismatch
The characteristic flavor and holes of Swiss cheese are caused by the fermentation products _______ and _______, respectively.
propionic acid; CO2
The genes that encode ribosomal RNA (rRNA) are referred to as
rDNAs
Base substitutions are more common in aerobic vs. anaerobic environments because of the production of ______ under aerobic conditions. reactive oxygen species DNA polymerase ATP guanine nucleotides
reactive oxygen species
These chemicals, produced in aerobic environments, result in increased base substitution because they oxidize guanine in DNA. intercalating agents major histocompatibility complexes (MHC) quaternary ammonium compounds reactive oxygen species (ROS)
reactive oxygen species (ROS)
As a group, Pseudomonas species ______.
have extremely diverse biochemical capabilities
An important trait of species of the thermophilic Thermus is their ______.
heat-stable enzymes
On blood agar, Streptococcus pyogenes produces β-_________ , a characteristic used to differentiate this organism from the normal oral microbiota.
hemolysis
Several new technologies to rapidly determine DNA sequences are referred to as ______ sequencing. high-throughput dideoxy-chain termination polymerase chain reaction
high-throughput
If DNA acquired through horizontal gene transfer is not a replicon, then a process called _________ recombination must occur for that DNA to be passed on to daughter cells.
homologous
When two bacterial strains that are His-/Trp- (require his and trp for growth) and Leu-/Thr- (require leu and thr for growth) are mixed together and plated on minimal media, any colonies that form are likely due to one strain acquiring genes from another strain. This is called ____________ gene transfer.
horizontal
The joining of genomic fragments to vectors creates molecules called __________ DNA molecules.
recombinant
In addition to using naturally-occurring mutants with desirable characteristics in biotechnology, researchers can now also use __________ ____________techniques to genetically alter organisms.
recombinant (or genetic) DNA (or engineering)
When horizontal gene transfer occurs between a donor and recipient cells, the resulting cells are called _________.
recombinants
The purple bacteria are Gram-negative organisms that can appear ______ due to their light-harvesting pigments.
red orange purple
Enzymes that cut DNA at or near specific DNA sequences are called ___________ ____________.
restriction enzymes (or endonucleases)
For characterizing strain differences among prokaryotes, whole genome sequencing (WGS) has now largely replaced _______.
restriction fragment length polymorphisms (RFLPs).
Chlamydia and Chlamydophila species can exist in the host as non-infectious ________ bodies which can replicate and later differentiate into smaller, dense-appearing infectious ________ bodies.
reticulate elementary
*Select all that apply* During the polymerase chain reaction (PCR), short strands that include only the target sequence are generated from ______ and ______ strands used as a template. full-length short mid-length
short mid-length
A(n) _________ mutation is a base substitution that does not change the encoded amino acid.
silent or synonymous
During conjugation, the F plasmid nucleic acid that transfers is ______. single-stranded RNA double-stranded RNA single-stranded DNA double-stranded DNA
single-stranded DNA
Microscopic examination is important in the presumptive identification of an organism because it can provide information on the organism's ______.
size and shape staining characteristics
In the Ames test, a control plate is used to show that reversion is due to the test chemical rather than to ______. spontaneous mutation thymine dimers glucose-salts medium rat liver enzymes
spontaneous mutation
When a restriction enzyme makes staggered cuts in a double-stranded DNA molecule, the fragments that result have single-stranded overhangs known as _______ ends.
sticky (or cohesive)
Bacteria such as E. coli are an excellent model system for genetics studies because they can quickly grow to high densities, allowing us to screen for rare genetic events. These can give rise to different __________ , which are genetic variants within a species.
strains
All of the following are reasons why sequencing the genes of small subunit (SSU) rRNA is extremely useful in classifying organisms EXCEPT ______.
the genes are often horizontally transferred
The genetic transfer mechanism shown here is called ____________ .
transformation
The process of bacterial ________ involves the uptake of "naked" DNA by competent bacterial recipient cells.
transformation
Mutagens that are DNA segments that can insert into genes and thereby inactivate them are called ______. transposons alkylating agents intercalating agents thymine dimers
transposons
When some species of bacteria reach a certain density or when nutrients are in short supply, they ______. turn on genes required for competence signal other cells to lyse begin nitrogen and carbon synthesis
turn on genes required for competence
The purple sulfur bacteria ______.
use hydrogen sulfide to generate reducing power may possess gas vesicles store sulfur in intracellular granules may be motile by flagella
The Food and Drug Administration (FDA) recently began organizing Genome Trakr, a network of laboratories that collect ______ for use in tracking outbreaks caused by various foodborne pathogens.
whole genome sequencing (WGS) data
If a scientist is working with bacteria that have the typical phenotype of those isolated from nature, the bacteria are considered to be ______ type. wild natural normal
wild
The term used to describe a gene when it is found in its natural, non-mutated, form is ___________ type.
wild
True or false: A limitation of sequencing small subunit ribosomal DNA (SSU rDNA) is that cultures must first be grown in the lab before DNA can be extracted for sequencing.
False
True or false: A point mutation always leads to a shift of the reading frame from the point of mutation downstream.
False
True or false: Bacteria use CRISPR for gene editing.
False
________ transduction results from a packaging error during the virus replication cycle, when a piece of bacterial DNA is included in the new virus particle.
Generalized
What are advantages of using amino acid sequences deduced from whole and partial genome sequences as a basis for determining relatedness?
It accounts for novel organisms not detected by standard techniques used to amplify SSU rDNA. Each organism has an assortment of different ribosomal proteins, allowing more comparisons of gene products.
______ is used to fix nucleotide incorporation errors that are missed by the proofreading function of DNA polymerase. SOS repair Excision repair Mismatch repair Polymerase repair Photoactivation
Mismatch repair
You isolate pleomorphic rods that are difficult to stain with the Gram-staining procedure. This organism is most likely a member of the genus ______.
Mycobacterium
Antibiotics that interfere with peptidoglycan synthesis are ineffective in the treatment of _______ infections because these organisms lack a cell wall.
Mycoplasma
In order to better track foodborne disease outbreaks, the CDC established a database called _________, which catalogs whole genome sequences of certain foodborne pathogens.
PulseNet
A bacteriophage consists of a genome made up of DNA or _________ , surrounded by a coat made up of __________.
RNA protein (or polypeptides, or proteins)
What happens after an F+ donor transfers a strand of an F plasmid to an F- recipient? both become F- It is not possible to predict the outcome. both become F+ The donor becomes F- while the recipient becomes F+.
both become F+
In a clinical lab, microscopic examination of a specimen is often enough to diagnose ______ because of their size and characteristic shape.
certain infections by eukaryotic parasites
This image shows two steps in a mechanism of DNA transfer called _________.
conjugation
Which of the following groups of bacteria is best described as a diverse group of photosynthetic Gram-negative bacteria that inhabit a wide range of environments?
cyanobacteria
A bacterium that receives a plasmid with a human insulin gene cloned into it will produce ______. (Assume that the plasmid has the components that allow expression of the gene in bacteria.) human insulin bacterial insulin neither type of insulin
human insulin
The normal habitat of Bacteroides species in humans includes the ______.
mouth genital tract intestines
Organisms most fit to survive in a given environment will predominate because they can reproduce more rapidly than others. This phenomenon is called ___________ _______________.
natural selection
Chlamydia and Chlamydophila are transmitted directly from person-to-person and live within host cells as ______ parasites.
obligate intracellular
Aerobic chemoorganotrophs gain energy via the _______, using O2 as a terminal electron acceptor.
oxidation of organic compounds
This figure shows the steps of ______, a process that repairs thymine dimers by breaking the covalent bonds that have formed between adjacent thymines. proofreading excision repair SOS repair photoreactivation
photoreactivation
Recognition and repair of errors in nucleotide incorporation by DNA polymerase is called ______. photoactivation proofreading excision repair mismatch repair
proofreading
Many DNA polymerases have the ability to detect and repair their own errors in nucleotide incorporation. This ability is called _________.
proofreading (or editing)
MALDI-TOF mass spectrometry is an important new technology in bacterial identification because it can identify an organism from a colony ______.
rapidly, often in less than 15 minutes based on the profile of its proteins
Most bacteria that grow in the presence of O2 are which of the following?
Catalase-positive
An organism that harvests energy by oxidizing inorganic chemicals, but not organic chemicals, is a
Chemolithotrophs
Because E. coli cells are not naturally competent, when used for cloning, they must be treated to induce them to take up DNA by the process of ______. transduction transformation competence conjugation
transformation
In prokaryotes, genes can be transferred from a donor to a recipient via three different mechanisms: ______ , _______ , and ________.
transformation (or bacterial transformation, or DNA-mediated transformation) transduction conjugation
Cloned genes introduced into a plant create ______ plants. transgenic identical polygenic cloned
transgenic
Variation in the color of corn kernels, as described by Dr. Barbara McClintock, is an example of the process called _______.
transposition
Which of the following are characteristic of Micrococcus species?
typically pigmented obligate aerobes salt tolerant
*Select all that apply* Genetic engineering is commonly used in the production of ______. vaccines pharmaceutical proteins transgenic plants designer babies
vaccines pharmaceutical proteins transgenic plants
Molecular techniques such as ______ have allowed scientists to determine the phylogeny of microorganisms.
DNA sequencing
A group of bacteria called green bacteria are ______.
Gram-negative
Which of the following is the goal of phylogenetic classification?
Group organisms according to their evolutionary relatedness.
______ repair is activated by extensive DNA damage and uses a polymerase that lacks proofreading ability, ultimately resulting in mutations. Excision Photoreactivation Proofreading SOS Mismatch
SOS
You are attempting to identify an unknown bacterium by detecting nucleotide sequences. The bacterium could be one of seven different species or related groups. How many different probes do you need in order to identify this culture?
Seven
A bacterium spontaneously developing resistance to 2 different types of antibacterial medications is ______ it developing resistance to just one of them. equally likely to much less likely than much more likely than
much less likely than
If a base substitution changes an amino acid-encoding codon to a stop codon what would it be called? nonsense mutation deletion mutation silent mutation frameshift mutation missense mutation
nonsense mutation
Chemical mutagens that modify ______ increase the odds of incorrect nucleotide incorporation during DNA replication. amino acids pentose sugars nucleobases monosaccharides
nucleobases
The _____ ______ ______ (PCR) is a technique that makes numerous copies of a given region of DNA in a matter of hours.
polymerase chain reaction
In penicillin enrichment, the penicillin selects against the ______ which can grow in the medium. heterotrophs prototrophs auxotrophs chemotrophs
prototrophs
Beneficial characteristics of nitrogen-fixing cyanobacteria include ______.
providing an important source of usable nitrogen and carbon in nutrient poor environments limiting atmospheric CO2 buildup
What PCR technique employs fluorescent markers? RT-PCR only both qPCR and RT-PCR qPCR only neither qPCR nor RT-PCR
qPCR only
The chance that a gene will undergo a mutation when a cell replicates its DNA prior to cell division is ______. more than 10-12 between 10-1 and 10-4 less than 10-1 between 10-4 and 10-12
between 10-4 and 10-12
*Select all that apply* Errors by DNA polymerase that incorporate the wrong nucleotide into replicating DNA can be repaired quickly by which two mechanisms? Mismatch repair Photoactivation SOS repair Excision repair Proofreading by DNA polymerase
Mismatch repair Proofreading by DNA polymerase
Several species of _______ are notable pathogens. These include the bacteria that cause tuberculosis and leprosy.
Mycobacterium
Some cyanobacteria have negative effects, such as producing ______.
toxins that can harm animals geosmin, which can influence the taste of drinking water
*Select all that apply* Which of the following are the three main methods of gene transfer in bacteria? transformation competition conjugation translocation transduction transposition
transformation conjugation transduction
Dr. Barbara McClintock determined that variegation in the color of corn kernels was due to the insertion of ______ elements into genes involved in pigment synthesis. bacteriophage intercalating retroviral transposable
transposable
Oxygenic phototrophs use ______ as a source of electrons for reducing power, generating O2.
water
Nitrogen-fixing cyanobacteria can incorporate both ______ and _______ into organic material, thus generating a form of these nutrients that can then be used by other organisms.
N2, nitrogen, or N CO2 or carbon dioxide
Members of the genus _________ are causative agents of gonorrhea and meningitis.
Neisseria
In some cases, a presumptive diagnosis can be made just from a visual identification based on knowledge of the patient's symptoms. For example, intracellular Gram-negative diplococci found in a urethral sample from a male are indicative of ______.
Neisseria gonorrhoeae
Choose the correct descriptions of serological tests.
Rely on differences of surface structure molecules such as components of the cell wall, capsule, flagella, or pili. Require detection by antibodies.
Lactic acid bacteria include all of the following genera EXCEPT _______.
Staphylococcus
Chemical mutagens that modify ______ increase the odds of incorrect nucleotide incorporation during DNA replication. nucleobases amino acids monosaccharides pentose sugars
nucleobases
Donor and recipient bacterial cells are connected by a sex ______ during conjugation. membrane receptor pilus cilium fimbria
pilus
Consider the image of the catalase test. The bubbles coming from the sample on the left indicate what?
production of O2, a positive result indicating the presence of catalase
_________ is the change of a mutated genetic sequence back to its original, non-mutated form.
reversion
Species of the genus Haemophilus have what characteristics?
Gram-negative coccobacilli "blood loving," as their name reflects often common inhabitants of the respiratory tract
Vectors used in molecular cloning typically have a(n) ______, meaning a gene that allows the researcher to eliminate any cells that have not taken up molecules containing the vector sequences. An example of such a gene is one that encodes resistance to an antibiotic. insertional inactivation second genetic marker cloning site selectable marker
selectable marker
The green bacteria are Gram-_________ organisms that are typically green or brownish in color.
negative
A branching diagram showing the evolutionary relationships among various organisms is referred to as a(n) ______.
phylogenetic tree
This figure shows the first two steps of a technique called the: _______ _______ _______ . (No abbreviations please)
polymerase chain reaction
Species of Pseudomonas ______.
possess polar flagella use oxygen as a terminal electron acceptor
A variation on standard PCR combines the methods of RT-PCR and qPCR in order to detect and determine the relative amount of a given RNA sequence in a sample without the need for gel electrophoresis. The combination method is called ______-______ RT-PCR
real time
The return of a gene from a mutated state to its original, non-mutated state is called a ______. reversion recombination regression repression revision
reversion
Purple sulfur bacteria typically use hydrogen ________ (H2S) to generate reducing power.
sulfide
In this diagram, step 5 was left out on purpose. You would expect it to show the formation of a _______. plasmid particle conjugative particle transducing particle transformative particle transposable element
transducing particle
A genetic element such as a plasmid or a bacteriophage that is used to introduce genetic material into a cloning host during recombinant DNA experiments is called a _________.
vector
Mycobacterium species stain poorly because their cell walls contain ______.
waxy lipids called mycolic acids
*Select all that apply* Which of the following are sources of "naked" DNA? Lysed (burst) bacterial cells Contained in bacteriophages Contained within bacteria that lack cell walls Secreted into the environment by bacteria
Lysed (burst) bacterial cells Secreted into the environment by bacteria
Why are pH indicators used in so many biochemical tests that aim to identify bacteria?
Many of the metabolic pathways being tested have acidic or basic end products, yielding a change in pH of the medium.
Choose the methods used to identify prokaryotes that are based on phenotypic characteristics.
Metabolic capabilities Culture characteristics Microscopic morphology
An anoxic atmosphere lacks
Oxygen
Extensively damaged DNA activates the _________ repair mechanism, which cannot always determine the correct nucleotide sequence, thus introducing mutations resulting from the repair process itself.
SOS
The F or fertility plasmid contains genes that are required for bacterial ________. conjugation transformation transduction competence
conjugation
Which of the following taxonomic designations is defined as a group of related species?
Genus
You are working in a clinical lab and are given a stool sample to analyze for suspected roundworms. What phenotypic characterization approach would give you the fastest presumptive answer?
Microscopic morphology
A diverse group of Gram-negative bacteria that obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrate are known as
Nitrifiers
Members of the genus ______ thrive in the dry and salty environment of the skin.
Staphylococcus
This member of the lactic acid group is a Gram-positive coccus that grows in the oral cavity and can cause pharyngitis.
Streptococcus pyogenes
Unlike many nucleic acid detection techniques, why does fluorescence in situ hybridization (FISH) not require an amplification step?
The probe binds to 16S rRNA, many copies of which are naturally present in multiplying cells.
*Select all that apply* If the vector being used in the cloning process has an ampicillin resistance gene as its selective marker and the lacZ' gene as its second genetic marker, what should be added to the medium to isolate transformed cells? X-gal beta-galactosidase penicillin ampicillin
X-gal ampicillin
A common consequence of a _____________ mutation is the appearance of an early stop codon that produces a shortened and thus non-functional protein.
frameshift
Serological typing distinguishes different bacterial strains based on characteristics of which of the following?
proteins and carbohydrates such as those that make up flagella, capsules, and lipopolysaccharide molecules
Escherichia coli O157:H7 is an enterohemorrhagic strain responsible for many cases of foodborne illness. The O157:H7 refers to the antigenic type of its lipopolysaccharide (the O antigen) and flagella (the H antigen). E. coli O157:H7 is therefore a ______ of E. coli.
serotype or serovar
A plasmid or other replicon into which a foreign DNA fragment can be inserted for cloning purposes is called a(n) _________.
vector
In molecular cloning, the DNA replicon in which the gene of interest is inserted functions as a carrier of that DNA, and is termed a(n) ______. vector marker vehicle amplicon
vector
*Select all that apply* Examples of conditions where bacteria can become naturally competent in the environment include ______. when they are exposed to extreme heat when there is a high density of bacteria when the bacterial DNA is damaged when certain nutrients are scarce
when there is a high density of bacteria when certain nutrients are scarce
*Select all that apply* Which of the following are caused by chemical mutagens? base substitutions double stranded breaks frameshift mutations thymine dimers
base substitutions frameshift mutations
The system for classifying organisms changes constantly because ______.
new information is always being discovered
*Select all that apply* Which of the following can be found in a bacteriophage? hybrid DNA/RNA genome nucleus lipid membrane protein coat protein genome DNA or RNA genome
protein coat DNA or RNA genome
An organism that has the same nutritional requirement as the wild type is said to be a(n) ______. - heterotroph - autotroph - auxotroph - prototroph - phototroph
prototroph
The Ames test measures the effect of potential carcinogens on the _______ rate of a histidine-requiring Salmonella auxotroph.
reversion (or mutation)
The rDNA genes specify the information needed to synthesize _________ RNA molecules. (No abbreviations please)
ribosomal
*Select all that apply* Some types of bacteria become competent ______. when there is a high concentration of bacterial cells when there is a low concentration of bacterial cells when nitrogen and carbon sources are plentiful when nitrogen or carbon sources are scarce
when there is a high concentration of bacterial cells when nitrogen or carbon sources are scarce
Click and drag on elements in order Put the three basic steps of the polymerase chain reaction (PCR) in order. Start with the earliest step at the top. DNA synthesis occurs Primers anneal to denatured DNA Template DNA is denatured
Template DNA is denatured Primers anneal to denatured DNA DNA synthesis occurs
When comparing two organisms using DNA hybridization, the process relies on what property of DNA?
The extent of hybridization reflects the degree of sequence similarity between the two organisms.
Which of the following accurately describe biochemical tests used to identify microorganisms?
They rely on differences in metabolic capabilities of microorganisms. They generally provide a more certain identification than just relying on colony morphology.
Early chemotrophs may have used all of the following pathways to harvest energy EXCEPT ______.
- aerobic respiration
A mutant that requires a growth factor is a(n) ______. - heterotroph - autotroph - auxotroph - prototroph - phototroph
- auxotroph
I say: "Gram-negative bacteria, that are typically kidney-bean-shaped cocci in pairs. You say:
"Neisseria"
Mycoplasma is medically significant because it includes a pathogen that causes ______.
"walking pneumonia" which cannot be treated with antimicrobials that target peptidoglycan synthesis
Which term refers to an organism that has a mutation? - Mutant - Wild type - Mutagen
- Mutant
Which of the following describes an organism's observable characteristics? - Serotype - Genotype - Phenotype - Haplotype
- Phenotype
*Select all that apply* Genetic change in bacteria occurs through which two mechanisms? - mutation - vertical gene transfer - horizontal gene transfer
- mutation - horizontal gene transfer
Bacteria are a great model system for genetic studies because when they are grown to very high numbers in small volumes of simple media ______. - the bacteria divide indefinitely so the population number remains constant - rare genetic changes that happen can be easily studied - the genetic makeup of the population is very stable and never mutates
- rare genetic changes that happen can be easily studied
Match the following genera of organisms with their description. 1 Lactococcus 2 Lactobacillus 3 Enterococcus
1 Lactococcus - Includes species used to make cheese 2 Lactobacillus - Common members of the microbiota in the mouth and the vagina during childbearing years 3 Enterococcus - Members typically inhabit the intestinal tract
This figure illustrates the potential outcomes of base substitution mutations. The column labeled with a zero (far left) indicates the wild type. Match each Arabic numeral to its correct designation.
1 synonymous substitution 2 missense mutation 3 nonsense mutation
Please match the components of a vector with their functions. 1. Origin of replication 2. Restriction enzyme recognition site 3. Selectable marker - Allows plasmid to replicate independent of host chromosome - Allows for elimination of bacterial cells that do not contain recombinant molecule or vector - Allows vector to be cut so that gene of interest can be inserted
1. Allows plasmid to replicate independent of host chromosome 2. Allows vector to be cut so that gene of interest can be inserted 3. Allows for elimination of bacterial cells that do not contain recombinant molecule or vector
Match the organism with the disease that it causes. 1. Chlamydia trachomatis 2. Chlamydophila pneumoniae 3. Chlamydophila psittaci
1. Chlamydia trachomatis - A common sexually transmitted disease 2. Chlamydophila pneumoniae - Atypical pneumonia 3. Chlamydophila psittaci - Psittacosis
When comparing phenotypic and genotypic methods of classification of organisms, which of the following best describe phenotypic methods?
Classification schemes that group organisms by phenotype have been largely replaced by DNA sequencing data. Phenotypic methods still provide an important foundation for prokaryotic identification. Some taxonomists believe classification should be based on more than just genotypic traits.
What is an advantage of phage typing for identifying different strains of bacteria?
It is a useful tool for laboratories that lack equipment to do genomic testing.
Facultative anaerobes preferentially use aerobic respiration if _______ is present.
O2
Which is a nucleic acid amplification test (NAAT)?
Polymerase chain reaction
Which of the following is not a characteristic of the lactic acid bacteria?
Possess the enzyme catalase
Classification
Process of arranging organisms into similar or related groups, primarily to make it easier to identify and study them
Identification
Process of characterizing an isolate to determine the group (taxon) to which it belongs
Which of the following help to explain why it is more difficult to determine the phylogeny of prokaryotes than that of plants and animals?
Prokaryotes have few differences in size and shape. The definition of species does not apply to prokaryotes in the same way as it does to plants and animals.
Members of which bacterial genus are used to make Swiss cheese?
Propionibacterium
Colony morphology can give hints as to the identity of the organism. Match the following examples of specific morphological features with the correct organism. Serratia marcescens Pseudomonas aeruginosa Streptococcus pyogenes
Serratia marcescens -often red when incubated at 22oC Pseudomonas aeruginosa- has a distinct fruity odor; often produces a soluble greenish pigment Streptococcus pyogenes- forms β-hemolytic colonies on blood agar
True or false: A point mutation involves any substitution of a single nucleotide.
True
A collection of clones that together contain the entire genome of an organism being studied is ______. a colony-forming unit a DNA library a cloning vector a restriction digest
a DNA library
All of the statements about GC content of prokaryotes are true EXCEPT ______.
if the GC content of two organisms is identical or nearly the same, the organisms are closely related
Nitrogen fixation occurs ______.
in anaerobic conditions only
In transformation, only one daughter cell inherits donor DNA. This is because ______. only a single strand of donor DNA integrates into the recipient chromosome the parent cell keeps one strand of donor DNA and donates the other to one daughter cell. the other daughter cell rejects the donor DNA strand
only a single strand of donor DNA integrates into the recipient chromosome
When trying to illustrate how DNA molecules in a molecular biologist's "tool kit" work, it is often helpful to use ______ on diagrams. only one or a few molecules millions of molecules
only one or a few molecules
An actual DNA transformation experiment is set up so that _______ grow under selective conditions. only nontransformed cells both transformed and nontransformed cells only transformed cells
only transformed cells
Pseudomonas aeruginosa can be described as a(n) _________ pathogen because it usually causes disease in patients who have underlying medical conditions.
opportunistic
Neither strain A (His-/Trp-) nor strain B (Leu-/Thr-) can grow on minimal media on their own because they cannot synthesize the indicated amino acids. If the strains are mixed and then plated onto minimal media, any colonies that form ______. should be a result of horizontal gene transfer are likely to be spontaneous mutants do not use any of those amino acids for growth
should be a result of horizontal gene transfer
Scientists group bacteria into different groups in order to ______. tell them apart from eukaryotic organisms determine where they were isolated show how different species are related
show how different species are related
A sequence in rRNA that characterizes either a certain species or a group of related organisms is called a(n) _____ sequence.
signature
A base substitution in a protein-encoding gene results in one of three possible mutation outcomes: ___________ mutation, _________ mutation, or ____________ mutation.
silent (or synonymous) missense nonsense
Staphylococcus epidermidis is part of the normal microbiota of the
skin
Chromosomal DNA is transferred with F plasmid DNA in an Hfr cell because ______. - the chromosomal DNA is fragmented into segments - the plasmid DNA and chromosomal DNA are similar in size - the plasmid DNA is integrated into the chromosome in these cells - the chromosomal DNA is homologous with the plasmid DNA
the plasmid DNA is integrated into the chromosome in these cells
Which DNA fragment will move fastest during gel electrophoresis? the longest molecule the shortest molecule the molecule with the highest GC% the molecule with the highest AT%
the shortest molecule
Of the different ribosomal RNA molecules found in prokaryotes, which is the most useful in taxonomy?
16S
In taxonomy, the most useful rRNA molecule is the _______ rRNA in prokaryotes and the _______ rRNA in eukaryotes.
16S 18S
What method are researchers today most likely to use in order to group organisms into a classification scheme?
16S rDNA sequence data
This figure shows the ribosomal components in prokaryotes. Which component is most often used in taxonomy?
16S rRNA
Which of the following is a property of Archaea?
70S ribosomes
Arrange the following events in the proper sequence for gene cloning. 1 = Incorporate gene into a bacterial plasmid, 2 = Isolate DNA from organism containing the desired gene, 3 = Incorporate cloned gene into bacterial cells, 4 = Cut DNA with restriction enzyme. 2, 4, 1, 3 1, 2, 3, 4 2, 3, 4, 1 2, 1, 4, 3 2, 4, 3, 1
2, 4, 1, 3
If you start with one double-stranded molecule of the target DNA and you perform SIX cycles of PCR, how many double-stranded copies of the DNA will you have? 32 6 64 12 128
64
What is the definition of biovar or biotype?
A group of strains that have a characteristic biochemical pattern.
Why can DNA sequences be viewed as evolutionary chronometers?
Accumulations of random mutations provide a relative measure of time elapsed since organisms diverged from a common ancestor.
______ _________ structurally resemble nucleobases and can be mistakenly used when cells make nucleotides, which are then incorporated by DNA polymerase into DNA.
Base (or Nucleobase) analogs
Which of the following genera consists of anaerobic Gram-positive rods that are commonly found as intestinal microbiota, particularly in breastfed infants?
Bifidobacterium
True or false: Scientists now understand the true diversity of microbial life and have determined the relationships between the millions of prokaryotes that exist.
False
What is a significant limitation of detecting specific nucleotide sequences in order to identify prokaryotes?
Each probe or amplification detects only a single possibility, so multiple probes/amplifications may be needed to uniquely identify.
DNA gel ________ is a laboratory technique for separating DNA fragments according to size by using an electric current to move the DNA through a gel-like matrix.
Electrophoresis
Which of the following pairs are matched correctly?
Enterococcus: found in the intestinal tract Lactobacillus: found in milk and other dairy products
DNA-DNA hybridization has demonstrated that members of what two genera would actually be grouped in the same species?
Escherichia and Shigella
When integrated F plasmid DNA in an Hfr cell is excised from the chromosome, an excision error can result in the removal of chromosomal DNA along with the F plasmid DNA, creating a plasmid called ______. Hfr F- F+ F'
F'
When integrated F plasmid DNA in an Hfr cell is excised from the chromosome, an excision error can result in the removal of chromosomal DNA along with the F plasmid DNA, creating a plasmid called _______. Hfr F' F- F+
F'
Which of the following strategies is least important when attempting to identify the causative agent of a patient's disease symptoms?
Identifying each and every organism present in the patient or patient's sample.
Nucleic acid amplification tests (NAATs) are most useful for which of the following?
Increasing the number of copies of specific DNA sequences
_______ selection is used to isolate an auxotroph from a prototrophic parent strain, because no selective medium exists to inhibit the parent.
Indirect (or Negative)
Methods used to increase the number of copies of specific DNA sequences can collectively be referred to as which of the following?
Nucleic acid amplification tests (NAATs)
When undergoing photosynthesis, anoxygenic phototrophs use hydrogen sulfide or organic compounds as a source of electrons to make reducing power. Thus, they do not generate ______.
O2
A reason why environments that are routinely exposed to O2 can support anaerobic growth is that ______.
O2-consuming organisms depletes the oxygen levels
How many strands of donor DNA integrate into a recipient chromosome during transformation? One Two None
One
Which of the following can purple non-sulfur bacteria use as an electron source?
Organic compounds Hydrogen sulfide Hydrogen gas
Which of the following are benefits of using a Gram stain to characterize an unknown prokaryote?
Provides information on the shape and arrangement of bacterial cells Can be conducted quite quickly in the laboratory Shows whether organisms appear to be growing as a pure culture or with other bacteria and/or host cells Distinguishes between Gram-positive and Gram-negative bacteria to narrow the list of possible identities
Which of the following are diseases caused by member of the Chlamydia and Chlamydophila species?
Psittacosis, a form of pneumonia A sexually transmitted infection that mimics gonorrhea Eye infections Atypical pneumonia
Which of the following PCR techniques utilizes cDNA? both qPCR and RT-PCR RT-PCR only neither qPCR nor RT-PCR qPCR only
RT-PCR only
Which of the following bacteria is typically a harmless resident of the skin?
Staphylococcus epidermidis
If a Gram stain of human sputum showed many white blood cells and Gram-positive diplococci, the most likely bacterium is which of the following?
Streptococcus pneumoniae
Why is a size standard always included on a DNA gel? - To supply intercalating dye so that the DNA bands will be visible after electrophoresis. - To fill up empty wells in the gel so that the electric current is constant. - To allow the researcher to determine the size of DNA fragments in unknown samples. - To determine the size of the proteins that the DNA codes for.
To allow the researcher to determine the size of DNA fragments in unknown samples.
The mechanism by which bacterial DNA is moved from one bacterium to another by a bacteriophage is called __________.
Transduction
_______ is the transfer of bacterial DNA from a donor to recipient via a bacteriophage. Conjugation Transposition Transformation Transduction
Transduction
Which mechanism of gene transfer involves the uptake of "naked" DNA by competent bacterial recipient cells? Conjugation Transformation Transduction Transposition
Transformation
Which of the following statements about transformation is correct? -Transformation is the uptake of naked DNA from the environment. -Transformation involves the formation of a sex pilus through which plasmid DNA is shared between bacteria. -Transformation is the transfer of DNA from one bacterial cell to another by means of a bacteriophage. -Transformation depends on a donor cell containing an F plasmid and a recipient cell that does not.
Transformation is the uptake of naked DNA from the environment.
For DNA to be visualized in a gel after electrophoresis, ______. a DNA-staining dye must be used the gel must be photographed the gel must be irradiated the gel must be refrigerated
a DNA-staining dye must be used
Filamentous sulfur oxidizers ______.
accumulate sulfur as intracellular granules
The purpose of a selectable marker, usually a gene that encodes resistance to an antibiotic such as ampicillin, is to ______. - allow researchers to eliminate any cells that have not taken up molecules containing vector sequences - speed up the rate of evolution within the bacterial population - mark those bacteria that have not taken up the vector so that they can be avoided - prevent contamination of the cultures with other strains of bacteria
allow researchers to eliminate any cells that have not taken up molecules containing vector sequences
A mutant which needs a particular nutrient to grow which the normal strain does not is called a(n) __________.
auxotroph
In replica plating, colonies from the master plate that grow on the nutrient agar plate but not on the glucose-salts plate are ______. pseudotrophs minimalists prototrophs auxotrophs
auxotrophs
In the Ames test, ______ are exposed to a possible mutagen and are then plated onto ______ medium to test for reversion. auxotrophs; glucose-salts prototrophs; glucose-salts prototrophs; nutrient agar auxotrophs; nutrient agar
auxotrophs; glucose-salts
A(n) __________ is a virus that infects bacteria, and some can transfer bacterial genes from a donor cell to a recipient cell.
bacteriophage
Bacterial viruses are known as ______.
bacteriophages
The method used to characterize different strains of bacteria that relies on differences in their susceptibility to _______ is called phage typing.
bacteriophages
Chemical mutagens can cause two types of mutations: ________ substitutions and ___________ mutations.
base (or base pair, or nucleobase) frameshift
Mutagens that modify nucleobases change their _______ - _________ properties.
base - pairing
The type of DNA damage repair illustrated here is _______. mismatch repair thymine dimer repair proofreading repair base excision repair
base excision repair
Foreign or altered DNA can be introduced into a recipient cell in a form that will be replicated and passed on to the cell's progeny. This procedure is known as ___________.
cloning
The procedure that involves inserting DNA into a vector to form a recombinant molecule that is then introduced into cells where it replicates is called molecular ______. sequencing cloning mapping hybridization
cloning
A bacterial cell described as ________ can take up DNA from the surrounding environment.
competent
Cells that have the ability to take up DNA from the environment are called _________ cells. competent immunogenic recombinant pathogenic
competent
In bacteria, __________ refers to DNA transfer requiring cell to cell contact.
conjugation
*Select all that apply* Knowing the sequence of a genome is useful in which of the following applications? determining protein sequences identifying genetic alterations associated with disease studying evolutionary relationships assessing lipid composition of cells
determining protein sequences identifying genetic alterations associated with disease studying evolutionary relationships
Campylobacter jejuni infections are commonly associated with ______.
diarrhea
Penicillin _________ is a technique in which mutant cells are incubated in glucose-salts broth with penicillin before plating on nutrient agar in order to increase the ratio of auxotrophs to prototrophs.
enrichment
Proteins that remove thymine dimers without light are termed __________ repair enzymes.
excision (or dark)
What molecular biology technique is portrayed in the image seen here? gel electrophoresis Southern blot polymerase chain reaction recombinant DNA technology
gel electrophoresis
Which of the following techniques can separate RNA or protein molecules based on their size? gel electrophoresis RT-PCR microarray analysis dot blotting
gel electrophoresis
The type of transduction that can transfer any genes of a host cell is called _________ transduction.
generalized
*Select all that apply* Transduction exists in two kinds. What are they? localized compartmentalized specific nonspecific generalized specialized
generalized specialized
In the filamentous bacterium Anabaena, specialized cells called _______ are used for nitrogen fixation in order to protect nitrogenase from O2.
heterocyst
In this micrograph of a cyanobacterial species, the structure that is labeled A is called a(n) _______.
heterocyst
Highly automated methods that generate huge amounts of DNA sequence data relatively quickly are termed _________-__________ (or next-generation) sequencing.
high throughput
Deinococcus species have the ability to withstand ______.
high doses of radiation
A probe used to identify a microorganism ______.
is a single-stranded piece of nucleic acid has a detectable tag or label is complementary to the sequence of interest
In a healthy individual, anaerobes can regularly be found on and in the ______.
oral cavity skin intestinal tract
Taxonomic categories include ________, which is defined as a grouping of similar families, and _______, which is a grouping of similar classes
order phylum
Chemoorganotrophs oxidize _________ compounds such as glucose to obtain energy.
organic
A replicon is a DNA molecule that contains a(n) ________ of ___________ .
origin replication
Pseudomonas species are Gram-negative rods that, unlike members of the family Enterobacteriaceae, are ______.
oxidase-positive nonfermenters
Viruses that infect bacteria and replicate in them are specifically called
phages
In the polymerase chain reaction (PCR), the _______ dictate which part of the DNA will be amplified.
primers
*Select all that apply* Which of the following are needed for the polymerase chain reaction (PCR)? DNA polymerase from Escherichia coli primers DNA polymerase from Thermus aquaticus DNA ligase template RNA deoxynucleotides template DNA
primers DNA polymerase from Thermus aquaticus deoxynucleotides template DNA
Obligate aerobes obtain energy using _______ exclusively; none of them can ferment.
respiration
Members of the filamentous bacterial species Anabaena protect the nitrogenase enzyme from O2 by ______.
restricting the process of nitrogen fixation to heterocysts where O2 is not generated
The pieces of DNA produced when restriction enzymes cut DNA are called ______ fragments. restriction polymerization probe primer
restriction
In a typical cloning procedure, the DNA of interest and the vector are cut with the same ___________ ____________ and then joined to form a recombinant DNA molecule.
restriction enzyme (or endonuclease)
Cancer-causing chemicals are called ________.
carcinogens
Chemicals that cause cancer are known as ______, and most of them are ______. carcinogens; teratogens mutagens; teratogens carcinogens; mutagens mutagens; carcinogens
carcinogens; mutagens
Coxiella burnetti is an oblicate intracellular bacterium that ______.
causes Q fever can form small cell variants (SCVs) that survive well in the environment
A key characteristic of the genus Mycoplasma is that they lack a ________ ________, instead usually relying on sterols in their membrane to provide strength and rigidity.
cell wall
Conjugation in bacteria requires ______. formation of a biofilm matrix the presence of bacteriophages contact between donor and recipient cell the isolation of chromosome fragments
contact between donor and recipient cell
he first step in a polymerase chain reaction (PCR) cycle requires a high temperature to _______. increase the rate of chemical reactions decrease the action of DNA polymerase force the complementary binding of nucleotides denature the DNA double helix
denature the DNA double helix
Phage typing relies on which of the following?
differences in susceptibility of various strains of a given bacterial species to bacteriophages
The hormone ___________ is a genetically engineered pharmaceutical protein that is used in the treatment of diabetes.
insulin
Mutations are rare because ______. most damage is repaired before it is passed on to progeny mutated DNA cannot be replicated, so it cannot be passed to progeny damage to DNA is a very uncommon event
most damage is repaired before it is passed on to progeny
Members of the family Enterobacteriaceae are _______.
Gram-negative rods
*Click and drag on elements in order* Place the steps of DNA-mediated transformation into the correct order. Start with the earliest at the top. -Strand being replaced by donor DNA is degraded. toggle button Strand being replaced by donor DNA is degraded. -Nucleases at the cell surface degrade one strand of the DNA; the other strand enters the cell. -Double-stranded DNA molecule binds to surface receptor. -Single-stranded DNA integrates into genome after entering the cell.
1. Double-stranded DNA molecule binds to surface receptor. 2. Nucleases at the cell surface degrade one strand of the DNA; the other strand enters the cell. 3. Single-stranded DNA integrates into genome after entering the cell. 4. Strand being replaced by donor DNA is degraded. toggle button
You have a sample containing bacteria that cannot yet be grown in culture. You decide to use 16s rDNA sequences to identify the bacteria. What is the correct order of steps you should use? Start with the earliest at the top.
1. Extract DNA from bacteria 2. Amplify the bacterial DNA 3. Sequence the 16S rDNA 4. Compare the 16S rDNA sequence with sequence of known organism
*Click and drag on elements in order* Place the steps of F plasmid transfer in the correct order. Start with the earliest at the top.
1. F pilis makes contact with recipient cell. 2. One strand of F plasmid is cut in origin of transfer. 3. Single strand of F plasmid is transferred to recipient cell. 4. Compliment of the transferred strand is synthesized.
Place in order the events that occur when performing phage typing. Start with the earliest event at the top.
1. The test organism 2. Drops of different 3. If the organism 4. The pattern of clearing
Match each of these widely used variations of conventional PCR with the appropriate description. 1. RT-PCR (reverse-transcription PCR) 2. qPCR (quantitative PCR) a. used to detect certain mRNA sequences in a sample b. used to amplify target sequence and monitor PCR product accumulation
1. a. used to detect certain mRNA sequences in a sample 2. b. used to amplify target sequence and monitor PCR product accumulation
Prior to the three-domain system, the most widely accepted scheme was the five-kingdom system, proposed by R. H. Whittaker in 1969. What were the major limitations of this system that the three-domain system solved?
It did not reflect the fundamental differences in chemical compositions of cell walls and cytoplasmic membranes between Archaea and Bacteria. It did not reflect ribosomal RNA data that indicates plants and animals are more closely related to each other than Archaea are to Bacteria.
*Select all that apply* What are some of the disadvantages of the SOS DNA polymerase? It has no proofreading ability. It only works on undamaged DNA. It can result in many mutations in the DNA. It competes with the standard DNA polymerase.
It has no proofreading ability. It can result in many mutations in the DNA.
In an experiment, donor DNA, DNase, and recipient cells are added to a mixture. The recipient cells are not transformed. This tells us what about the donor DNA? It is contained within cells. It is contained within bacteriophages. It is naked.
It is naked.
Which of the following are accurate descriptions of PulseNet?
It is used to more readily recognize and trace multistate foodborne disease outbreaks It is a database cataloging whole genome sequences of certain foodborne bacterial pathogens.
Why should you load DNA of known sizes into the agarose gel? - It makes it easier to determine sizes of unknown DNA fragments using comparison techniques. - to fill in all the slots on the gel so you can run it - so you know how long the gel needs to run - to practice loading the DNA before you get to the important DNA
It makes it easier to determine sizes of unknown DNA fragments using comparison techniques.
______ is a revolutionary new technology being used in clinical labs that can rapidly identify an organism based on its protein profile.
MALDI-TOF mass spectrometry
Why are sequences of ribosomal RNA so useful in microbial classification and identification?
The sequences are relatively stable, since the ribosome would not function with too many mutations. Once a sequence is determined, it can be compared with sequences of known organisms by searching extensive databases. They allow identification without culturing the organism.
More than 300 cases of salmonellosis occur within a large city. Each time, Salmonella enterica is isolated from the feces of the patient. Based on that information, the news media report that there must be a common source to all these cases. What additional information would be needed to support or disprove this view?
The specific strain of the Salmonella would need to be identified.
Consider the urease tests, shown. The tube on the right is an uninoculated control. What does the tube on the left tell us?
The tube on the left is a positive result for urease production.
Which of the following statements about Pseudomonas species are true?
They are able to metabolize unusual sugars and amino acids. They can degrade environmental compounds that many other organisms cannot.
Which of the following statements describe Bordetella species?
They are aerobic Gram-negative coccobacilli. The most significant medical species causes whooping cough.
Which of the following accurately describe DNA probes?
They are short, single-stranded pieces of DNA of a particular sequence of interest. They rely on complementary base pairing in order to bind their target DNA.
Why are nitrifiers of concern regarding their environmental impact?
They consume dissolved O2 from waterways contaminated with nitrogen-containing wastes. They convert ammonium fertilizer to nitrate, which is more easily leached from soils.
What are the characteristics of purple nonsulfur bacteria?
They grow as phototrophs. They lack gas vesicles.
Which of the following statements about members of the family Enterobacteriaceae is NOT true?
They only reside in the intestinal tract of humans.
Which of the following statements best describes mutation rates of genes? They are commonly as low as zero. They do not occur randomly. They range between one in 10 and one in 100. They range between one in 10,000 and one in a trillion.
They range between one in 10,000 and one in a trillion.
______ are segments of DNA that can move from one location to another in a cell's genome. Plasmids Transposons Mutagens Transcripts
Transposons
True or false: The native or wild type strain describes the typical phenotype of strains isolated from nature.
True
True or false: Advances in DNA sequencing methods are making it practical to use whole genome sequencing (WGS) to trace outbreaks of foodborne pathogens.
True
True or false: Cyanobacteria are morphologically diverse, ranging in shape from unicellular organisms to filamentous multicellular associations.
True
True or false: Incorporation of an incorrect nucleotide in a molecule of DNA results in a distortion of the DNA helix that can be detected by repair enzymes.
True
True or false: Methane gas produced by methanogens can be collected and used for generating electricity.
True
True or false: Purple non-sulfur bacteria can grow as phototrophs, or as chemotrophs in the absence of light.
True
True or false: Scientists sort living organisms into different groups to show the relationships among the species.
True
True or false: Some methods of detecting specific nucleotide sequences make it possible to identify organisms that cannot yet be grown in culture.
True
True or false: The development of recombinant DNA techniques has had a huge impact on many different aspects of society including agriculture and medicine.
True
True or false: When attempting to identify the organism causing a disease, it is not generally necessary to identify each and every organism present.
True
True or false: Methane gas produced by methanogens can be collected and used for generating electricity.
True
Which of the following statements about microbial diversity is true?
We are only now beginning to understand the diversity of prokaryotes.
You work in a clinical lab. A sample you cultivated overnight on blood agar yielded β-hemolytic colonies, suggestive of Streptococcus pyogenes, a member of the lactic acid bacteria. Unlike most bacteria that grow in the presence of O2, lactic acid bacteria are catalase-negative. If a catalase test on a colony yielded a positive result, what would this tell you about the identity of your organism?
Your sample is not Streptococcus pyogenes.
In conjugation in E. coli, an Hfr cell refers to ______. - a cell in which the F plasmid has been degraded by DNase - a cell that has combined with the other cells by sexual reproduction - a cell that has donated its F plasmid to a recipient cell - a cell with an intact F plasmid which is separate from the chromosome - a cell in which the F plasmid has been integrated into the cell chromosome
a cell in which the F plasmid has been integrated into the cell chromosome
family order class phylum
a collection of similar genera a collection of similar families a collection of similar orders a collection of similar classes
A dichotomous key is a ______.
a flowchart of tests that each yield a positive or negative result to aid in identifying bacteria
The easiest way to detect if streptomycin sensitive (StrS) cells are transformed with DNA from streptomycin resistant cells (StrR) is by growing the cells on ______. a medium containing streptomycin a minimal medium like glucose-salts agar a rich medium like TSA (trypticase soy agar)
a medium containing streptomycin
In a MALDI-TOF assay,
a microorganism's proteins are separated and sorted by mass to generate a profile that provides a fast way to identify a colony.
*Select all that apply* When cloning DNA using a pUC vector, if cells form white colonies when plated on media containing X-gal, then the transformed cells contain ______. a non-functional lacZ' gene a recombinant molecule (pUC with an insert) intact pUC vector a functional lacZ' gene
a non-functional lacZ' gene a recombinant molecule (pUC with an insert)
When treating tuberculosis, two or more antimicrobial medications are often prescribed because ______. -a sensitive cell is unlikely to become resistant to two medications simultaneously through separate spontaneous mutations -taking only one type of medication greatly increases the mutation rate of the bacteria
a sensitive cell is unlikely to become resistant to two medications simultaneously through separate spontaneous mutations
Base ______ structurally resemble nucleobases and can be mistakenly incorporated into nucleotides and then into DNA. donors analogs pairs adapters
analogs
Scientists can use a modified Cas9 nuclease as molecular scissors to cut precisely at a specific DNA sequence within a cell, guided by ______. - the cell's own promoter sequences - a single-stranded RNA that recognizes that sequence - a set of coenzymes that assist in the process - fluorescent markers that highlight the appropriate site on the chromosome
a single-stranded RNA that recognizes that sequence
The catalase test detects a microorganism's ______.
ability to break down hydrogen peroxide to form O2 and water
Before molecular techniques were available, bacteria were often classified based on ______.
ability to degrade different compounds cell wall type
Cyanobacteria living in aquatic environments can ______.
accumulate in larger numbers, which is referred to as a bloom move vertically through a water column using gas vesicles
A special staining procedure called the ______ is used in the identification of Mycobacterium species.
acid-fast stain
When a patient is suspected of having tuberculosis, what staining procedure is often done on the patient's sputum sample to help identify Mycobacterium tuberculosis?
acid-fast stain
*Select all that apply* Examples of how recombinant DNA techniques have affected society include their impact on ______. agriculture medical diagnoses computer engineering forensics
agriculture medical diagnoses forensics
The photosystems of cyanobacteria are similar to those of ______.
algae plants
Chemicals called ______ add alkyl groups onto nucleobases, changing their base-pairing properties. phospholipids polymerases alkylating agents thymine dimers
alkylating agents
*Select all that apply* Some prokaryotes are naturally competent ______. all the time at random times during their growth only under specific conditions when their DNA is damaged
all the time only under specific conditions
In order to distinguish different strains of bacteria, an antibiogram relies on ______.
differences in susceptibility to various antibiotics
*Select all that apply* To isolate bacterial cells that have been transformed with recombinant DNA, the cells are grown in media ______. differential for cells that carry the recombinant plasmid selective for cells with vector sequences differential for cells that are resistant to transformation selective for cells without vector sequences
differential for cells that carry the recombinant plasmid selective for cells with vector sequences
Gram-positive pleomorphic rods that are club-shaped and arranged to form V shapes or palisades (side-to-side stacks) are referred to as ______ or ______.
diphtheroids coryneforms
Mutants that can grow under conditions in which the parent (wild type) cells cannot are easily isolated by ________ selection.
direct
Selecting penicillin-resistant mutants by plating them on a medium containing penicillin is an example of ______ selection. differential degenerate indirect direct
direct
Mutant cells in bacterial cultures can be isolated by _________ selection and ________ selection methods.
direct indirect
Match the following taxonomic ranks of the bacterium Escherichia coli with the correct category. domain phylum family genus species
domain - bacteria phylum - proteobacteria family - enterobacteriaceae genus - Escherichia species - coli
A transducing particle carries ______. donor cell DNA phage DNA phage DNA and recipient DNA recipient cell DNA
donor cell DNA
Because the skin is ______, growth of many organisms is prevented.
dry and salty
When transforming cells as part of a cloning procedure, using bacteria such as E. coli that are not naturally competent, DNA can be introduced by ______, a procedure that creates temporary holes in the cytoplasmic membrane by exposing the cells to an electric current. transduction electroporation conjugation
electroporation
Which step of the polymerase chain reaction (PCR) involves the synthesis of complementary strands of DNA? termination denaturation digestion elongation priming
elongation
This figure illustrates the concept of a DNA __________.
library
Replica plating _______. - is useful for direct selection of antibiotic resistance and allows for the identification of auxotrophs - is useful for direct selection of antibiotic resistance and allows for the identification of prototrophs - employs a medium on which the mutant will grow but the parental cell type will not, and so is useful for identifying prototrophs - employs a medium on which the mutant will grow but the parental cell type will not, and so is useful for identifying auxotrophs - employs a medium on which the mutant will not grow but the parental cell type will, and so is useful for identifying auxotrophs
employs a medium on which the mutant will not grow but the parental cell type will, and so is useful for identifying auxotrophs
A cloning vector typically includes a second genetic marker which _______. - encodes resistance to an antibiotic to eliminate any cells that have not taken up a vector - contains an origin of replication sequence to allow the synthesis of any vector taken up by the host cell - encodes an observable characteristic to identify cells that contain a recombinant molecule
encodes an observable characteristic to identify cells that contain a recombinant molecule
The repair of thymine dimers by enzymes that make single-stranded cuts that flank both sides of the thymine dimer is called ______ repair. photoreactivation SOS excision proofreading mismatch
excision
The repair of thymine dimers by enzymes that make single-stranded cuts that flank both sides of the thymine dimer is called ______ repair. proofreading mismatch excision SOS photoreactivation
excision
When considering its taxonomic classification, Escherichia coli belongs to the ______ Enterobacteriaceae.
family
The presence of coliforms such as Escherichia coli in food and water indicates the possibility of ________contamination.
fecal
An anaerobic chemoorganotroph that uses glucose for energy and pyruvate as its terminal electron acceptor is performing ______.
fermentation
Facultative anaerobes can use aerobic respiration if O2 is present and _______if O2 is not available
fermentation
Once fragments of DNA have been separated using gel electrophoresis, the DNA bands are typically visualized by using a(n) _______. fluorescent dye complex stain spectrophotometer
fluorescent dye
A common consequence of a __________ mutation is the appearance of an early stop codon that produces a shortened and thus non-functional protein.
frameshift
Enterobacteriaceae get their name because they reside in the ______ tract of humans and animals.
intestinal
A modified version of Cas9 can be used for gene editing, a process that ______. - swaps chromosomes between cells from different organisms - removes individual chromosomes from a cell - replaces genes on the chromosome with sequences of mRNA - introduces targeted changes into the existing nucleotide sequence of a cell's genome
introduces targeted changes into the existing nucleotide sequence of a cell's genome
Complementary DNA (cDNA) produced from mature mRNA is used in cloning most eukaryotic genes, since it lacks ________ , or sequences of DNA that disrupt the coding sequences of eukaryotic genes.
introns
Chromosomal DNA that is transferred from an Hfr cell but does not integrate into the recipient's chromosome ______. is degraded replicates is translated circularizes
is degraded
*Select all that apply* RT-PCR (reverse-transcription PCR) is a widely used variation of conventional PCR that ______. is used to detect certain mRNA sequences in a sample monitors the accumulation of PCR product in real time is specifically used to amplify genes from retroviruses amplifies cDNA that is reverse transcribed from mRNA template
is used to detect certain mRNA sequences in a sample amplifies cDNA that is reverse transcribed from mRNA template
When diagnosing Helicobacter pylori infections, the urea breath test is preferred because ______ than other options.
it is cheaper and faster it is less invasive
The taxonomic category called _______ is a collection of similar phyla or divisions.
kingdom
Order from largest to smallest: family genus order kingdom class species phylum
kingdom phylum class order family genus species
In 2019, 137 reported cases of diarrheal disease involved a specific strain of Salmonella enterica that was linked to consumption of pre-cut melons. This led to a recall of the products by the supplier. Why was it important to identify the specific strain in order to limit this outbreak?
knowing the strain made it possible to link these 137 cases in order to identify the source
A patient suspected of having Helicobacter pylori would drink a solution containing ______ in order to test for the presence of the enzyme ______.
labeled urea; urease
During the second step of a polymerase chain reaction (PCR) cycle, the temperature is lowered. This results in ______. the primers annealing to their complementary sequences the dsDNA template denaturing as a result of the heat DNA polymerase synthesizing new DNA
the primers annealing to their complementary sequences
When trying to determine whether the patient has Helicobacter pylori, the cheaper and faster option would be ______.
the urea breath test
Spontaneous mutations are important because ______. they allow horizontal gene transfer between bacteria they allow populations of bacteria to adapt to a changing environment
they allow populations of bacteria to adapt to a changing environment
All of the following are true of the genus Clostridium EXCEPT ______.
they are Gram-negative rods
Regardless of whether they are genetically related or not, certain groups of bacteria (e.g. lactic acid bacteria) are often grouped together by scientists because ______.
they have similar physiological characteristics
Ultraviolet radiation causes covalent bonds to specifically form between adjacent ________ molecules on a DNA molecule.
thymine (or pyrimidine)
Ultraviolet radiation causes a very specific type of DNA damage called ______. thymine dimers double-strand breaks transduction base analogs recombination
thymine dimers
Rickettsia rickettsii causes Rocky Mountain spotted fever, which is transmitted through the bite of a ______.
tick
*Select all that apply* In a biotechnology lab, restriction enzymes are used ______. to cut DNA predictably into fragments for recombinant DNA technology to repair mutated DNA to synthesize new proteins to protect against foreign DNA
to cut DNA predictably into fragments for recombinant DNA technology
The majority of transposons contain _______ terminators. translational transcriptional replicational
transcriptional
Match each the different length strand generated during the polymerase chain reaction (PCR) with its description. 1. Full-length strand 2. Mid-length strand 3. Short strand a. Target strand that serves as template for more like-sized strands, yielding molecule that is amplified exponentially b. Serves as template for synthesis of short strand c. Serves as template for synthesis of mid-length strand
1. c 2. b 3. a
Please match the components of a polymerase chain reaction (PCR) with their role. 1. Double-stranded DNA 2. Taq polymerase 3. Primers 4. Deoxynucelotides a. Short DNA molecules that determine site of amplification in target DNA b. Enzyme that copies target DNA sequence c. Template containing target sequence d. Building blocks of DNA
1. c 2. b 3. a 4. d
Arrange the following in the proper sequence in which they occur during a single PCR cycle. 1. Addition of DNA nucleotides by Taq polymerase 2. Complementary base pairing between primers and target DNA 3. Heat separation of strands of target DNA 2, 1, 3 2, 3, 1 3, 2, 1 1, 2, 3 3, 1, 2
3, 2, 1
When two prokaryotic strains are compared by DNA hybridization, what is the minimum percent similarity they need to show to generally be considered members of the same species?
70%
Which of the following are properties of Bacteria?
70S ribosomes peptidoglycan cell wall
Which of the following results indicate that the bacterial strain being tested is susceptible to a specific bacteriophage?
A clear area on the hazy layer of bacterial cells being tested
On what general principle do commercial variations of traditional biochemical tests operate?
A series of tiny wells containing different media are inoculated; metabolic activities yield a pattern of color changes used for identification.
Describe some growth conditions or characteristics that enable Pseudomonas aeruginosa to be a problem in hospital environments.
Ability to grow in nutrient-poor environments Resistant to disinfectants Resistant to antibiotics
_______ gain energy via the oxidation of reduced inorganic chemicals, using O2 as a terminal electron acceptor.
Aerobic chemolithotrophs
*Select all that apply* Why is Taq polymerase used in the PCR reaction? Taq polymerase is a special type of polymerase that can copy any type of template DNA. Taq polymerase is heat-stable and can withstand the high temperature used in the denaturation step of the reaction. Taq polymerase is a synthetic enzyme that is easy to produce in a laboratory. Using heat-stable polymerase prevents the need to add more enzyme at each PCR cycle.
Taq polymerase is heat-stable and can withstand the high temperature used in the denaturation step of the reaction. Using heat-stable polymerase prevents the need to add more enzyme at each PCR cycle.
The image shows results of the urease test. What does the positive result (pink tube on the left) tell us about the organism?
The organism produces urease, which degrades urea to CO2 and ammonia, increasing the pH of the medium to produce a color change in the indicator.
Which of the following is a major advantage of detecting specific nucleotide sequences to identify prokaryotes?
The organisms do not need to be grown in culture.
*Select all that apply* Which of the following statements about PCR primers are true? Only one primer is necessary for any PCR reaction. The primers are complementary to template DNA. Primers are designed to anneal to the template DNA at each end of the target DNA. The primers are composed of RNA and DNA.
The primers are complementary to template DNA. Primers are designed to anneal to the template DNA at each end of the target DNA.
*Select all that apply* qPCR (quantitative PCR), also called real-time PCR, ______. allows quantification of the relative amount of DNA initially in the sample based on the amount of fluorescence is used to monitor the accumulation of PCR product uses a fluorescent marker to allow detection of PCR product requires gel electrophoresis at the end in order to quantify the amount of product generated
allows quantification of the relative amount of DNA initially in the sample based on the amount of fluorescence is used to monitor the accumulation of PCR product uses a fluorescent marker to allow detection of PCR product
After sequencing the gene of interest, the ______ ________sequence of the encoded protein can be established.
amino acid
In addition to being photosynthetic, many cyanobacteria have the ability to convert nitrogen gas (N2) into ______, a process known as nitrogen fixation.
ammonia
Nitrifiers are composed of two metabolically distinct groups: the _________ oxidizers, which convert ammonia to nitrite, and the _______ oxidizers, which convert nitrite to nitrate.
ammonia or ammonium nitrite
Two metabolically distinct groups of nitrifiers, the ______, typically grow in close association and together can oxidize ammonium to nitrate.
ammonia oxidizers and nitrite oxidizers
The main purpose of PCR is to _______. digest DNA detect DNA separate DNA amplify DNA sequence DNA
amplify DNA
Chemoorganotrophs that perform ______ often use sulfur or sulfate as a terminal electron acceptor.
anaerobic respiration
Which of the following were likely the earliest photosynthesizing organisms?
anoxygenic phototrophs
Antibiotic susceptibility patterns, like the one shown, are called
antibiograms
Most of the anaerobic chemolithotrophs that have been discovered are members of what domain?
archaea
Purple non-sulfur bacteria would not be found in ______.
arid environments
A(n) ________ mutation results from an insertion or deletion of nucleotides, leading to a shift of the reading frame from the point of mutation downstream.
frameshift
The top panel in this figure indicates the wild type sequence. What type of mutation does the bottom panel illustrate? nonsense base substitution frameshift synonymous missense
frameshift
The process of altering an organisms genetic information in vitro is called ______. mutations natural selection random mutagenesis genetic engineering
genetic engineering
Chymosin or rennin, which is used to coagulate milk in cheese production, is now commonly made by ______. genetically engineered bacteria creating it from scratch in the lab isolating it from cow stomachs
genetically engineered bacteria
Consider a population of bacteria susceptible to an antimicrobial. If a bacterium acquires a spontaneous mutation that gives resistance to the antimicrobial, this bacterium will ______ if the population is exposed to the antimicrobial. grow without competition grow as well as all the other bacteria not grow as well as all the other bacteria
grow without competition
Engineered Cas9 nucleases recognize and bind to particular DNA or RNA sequences with the help of ______. telomeric DNA guide RNA restriction enzymes cloning vectors
guide RNA
All of the following are characteristic of green sulfur bacteria EXCEPT one. Which?
have color pigments that are located in structures called trichomes
Cyanobacteria have photosystems that ______.
have pigments other than chlorophyll that contribute to their blue-green or reddish color
Examples of genetically unrelated bacteria that are informally grouped based on certain distinctive characteristics include ______.
lactic acid bacteria sulfate reducers endospore-formers
Enteric bacteria that ferment ______ are called coliforms.
lactose
A recently developed meat substitute uses soy _______ produced by genetically engineered microorganisms to give a more authentic flavor to the product. leghemoglobin lactoferrin myoglobin transferrin
leghemoglobin
A collection of DNA fragments that have been cloned into vectors for further study is called a DNA ________.
library
The O157:H7 strain of E. coli is particularly virulent. The O refers to the antigenic type of the _______, and the H refers to the antigenic type of the _______.
lipopolysaccharide; flagella
Choose the pair of phrases that best completes the following scenario: Consider two organisms that diverged from a common ancestor at some point in history. If there are many differences in the sequences of their DNA, this indicates they diverged ______: if there are few differences, this indicates they diverged ______.
longer ago; more recently
Double-stranded cDNA is made from mature ________ using a combination of the enzymes _________ _________ and DNA polymerase.
mRNA (or messenger RNA) reverse transcriptase
Choose the environments that would most likely support the growth of methanogens.
marine sediment sewage human digestive tract swamp
Based purely on DNA-DNA hybridization criteria used for bacteria, humans and chimpanzees would be ______.
members of the same species
Agarose gel electrophoresis separates nucleic acid fragments according to ___________. shape. nucleobase sequence. density. type of 5-carbon sugar. size.
size
Random genetic changes that result from normal cellular processes are ______. spontaneous mutations induced mutations synonymous mutations
spontaneous mutations
Treponema pallidum causes the sexually transmitted disease in humans called ______.
syphilis
is the science that studies organisms in order to arrange them into groups; it can be viewed as three separate interrelated areas: identification, classification, and nomenclature.
taxonomy
Bacteria are given names according to internationally recognized rules based on which of the following?
the International Code of Nomenclature of Prokaryotes
In the picture shown, which culture shows a positive test for catalase production?
the culture on the left
Wolbachia pipientis is significant medically in diseases such as river blindness and elephantiasis because ______.
the immune response to the bacteria contributes to chronic inflammation in these diseases it resides within the filarial worms that cause these diseases
Presence of the enzyme ________ is a key characteristic of Staphylococcus species that is used to distinguish them from Gram-positive cocci that do not respire aerobically, such as Streptococcus species.
Catalase
You are attempting to identify a bacterium that you are unable to culture in lab. Which set of techniques would best help you attempt to identify this bacterium?
DNA amplification followed by rDNA sequencing
______ sometimes incorporates the incorrect nucleotide when generating a new strand of DNA during DNA ______; this leads to a detectable distortion in the DNA helix. DNA polymerase; transcription DNA polymerase; replication RNA polymerase; transcription RNA polymerase; replication
DNA polymerase; replication
This figure shows a cell with an integrated F plasmid. If this plasmid is incorrectly excised, the result could be an F plasmid that carries along a portion of the bacterial chromosome. Such a cell would then be called a(n) _________ cell.
F' (or F prime)
After transfer of the F plasmid is complete, both the donor and recipient cells are now considered _________ , so they can act as donors of the F plasmid.
F+
True or false: Gram stain results are necessary and sufficient to diagnose the cause of an infection.
False
Members of the genus ________ , such as the causative agents of tuberculosis and Hansen's disease, are examples of acid-fast organisms.
Mycobacterium
*Select all that apply* Knowing the sequence of a genome is useful in which of the following applications? assessing lipid composition of cells identifying genetic alterations associated with disease determining protein sequences studying evolutionary relationships
identifying genetic alterations associated with disease determining protein sequences studying evolutionary relationships
Genes into which transposons "jump" are usually ______ by the event. activated unaffected inactivated
inactivated
In the Ames test, it is expected that a mutagen would ______ the reversion rate of of a histidine-requiring auxotroph of Salmonella. increase have no effect on decrease
increase
Mutations that are caused by external influences such as radiation or chemicals are called ______ mutations. anonymous transposable induced spontaneous
induced
Nitrifying bacteria _______. Thus, levels of this gas can quickly decrease in aquatic environments.
oxidize nitrogen compounds using O2
As a group, chemolithotrophs ______ to obtain energy.
oxidize reduced inorganic chemicals such as hydrogen gas
Acidithiobacillus species can be used to prevent acid rain, a problem that occurs when sulfur-containing coals and oils are burned. The bacteria are allowed to ______, a form that can then be extracted.
oxidize the sulfur to sulfate
Restriction enzymes recognize and cleave DNA at sequences which are typically ______, meaning they are the same on both strands when read 5' to 3'. palindromes polygenic antisense promoters
palindromes
A diagram that uses a branching pattern to depict the evolutionary heritage of organisms is called a(n) ___________ ____________.
phylogenetic tree
What term describes the evolutionary history of organisms?
phylogeny
Members of which bacterial genus are involved in the genetic engineering of plants? Escherichia Saccharomyces Agrobacterium Mycobacterium Staphylococcus
Agrobacterium
The cytoplasmic membrane lipids of members of the domain _______ are composed of hydrocarbons (not fatty acids) linked to glycerol by ether linkage.
Archaea
The revolutionary system of classification proposed by Woese and his colleagues separated prokaryotes into two domains: _______ and ________.
Bacteria Archaea
A single-stranded piece of DNA labeled with a detectable tag (e.g., fluorescent dye or radioisotope) is called a ______.
DNA probe
The function of a labeled dCas molecule along with gRNA could best be compared to which of the following molecules? Restriction enzyme DNA probe Vector Reverse transcriptase DNA ligase
DNA probe
In humans, two of the genes associated with the development breast cancer encode enzymes involved in ______. DNA repair DNA damage cell death mutagenesis
DNA repair
Methanogens are a group of _______ that produce methane by oxidizing _______.
archaea; H2
Nitrifiers can be described as bacteria that ______.
are Gram-negative obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrite
Haemophilus species ______.
are Gram-negative coccobacilli that require hematin and/or NAD for growth
Sulfur-reducing bacteria have a positive impact on the environment because they ______.
are an essential component of the sulfur cycle
Based on their defining characteristics, members of the family Enterobacteriaceae ______.
are facultative anaerobes ferment glucose possess peritrichous flagella if motile
When using a pUC 18 vector for cloning, cells that carry intact vector after transformation will form ______ colonies, because they have a functional lacZ' gene. white blue
blue
True or false: In bacterial conjugation, all F+ donor cells are high frequency recombinant (Hfr) cells.
False
True or false: When an Hfr cell transfers chromosomal DNA to a recipient cell, it does not need to produce an F pilus.
False
When bacteriophages replicate, phage components are synthesized in the host cell and assemble into new viruses ___________. when the bacterial cell enters a new eukaryote host after the components are released from the host cell within that cell before being released within the nucleus of the host cell before release
within that cell before being released
A _______ indicator is commonly used in biochemical tests to show the production of acid or base by changing from one color to another.
chemical
*Click and drag on elements in order* Place the following in order to indicate the naming process for restriction enzymes.
1. First letter of the bacterial genus 2. First two letters of bacterial species 3. Number showing the order discovered in the bacterium
*Select all that apply* Which of the following are involved in the naming process for restriction enzymes? Discovering scientist Genus name Year of discovery Species name Number showing order of discovery Palindrome recognized
Genus name Species name Number showing order of discovery
Like the green and purple bacteria, members of the genus Heliobacterium are also examples of anoxygenic phototrophs. They are ______ bacteria related to members of the genus Clostridium
Gram-positive rod-shaped endospore-forming
You sequence the genome of an organism and measure the relative amount of each nucleotide. After measuring the percent of cytosine at 20%, what can you safely conclude about the percentages of the remaining nucleotides?
Guanine is 20%; adenine and thymine are each 30%.
Which of the following are accurate descriptions of the newest edition of Bergey's Manual of Systematic Bacteriology?
It includes information on methods for maintenance and preservation of organisms. It classifies all known prokaryotes based on their phylogeny. It includes information on ecology, methods of enrichment, culture, and isolation of organisms.
What are some difficulties in using phenotypic characterizations for the phylogenetic classification of prokaryotes?
Organisms that appear dissimilar may be closely related. Phenotypic differences can be due to only a few gene products. Phenotypically similar organisms may be only distantly related.
Which of the following does Wolbachia pipientis directly infect?
Parasitic worms Arthropods
A laboratory technique used to determine the specific order of nucleotides in DNA is called DNA __________.
sequencing
*Select all that apply* Different versions of Cas9 can be used ______. to deliver molecules to certain chromosomal locations for gene editing to translate genes into proteins to block transcription of individual genes to reverse transcribe mRNA into DNA
to deliver molecules to certain chromosomal locations for gene editing to block transcription of individual genes
