Which is true about biological reduction of nitrogen gas to ammonia?
Can be accomplished by free-living organisms in Domains Archaea and Bacteria
Can be accomplished by a variety of symbioses between prokaryotes and eukaryotic macro organisms
Is thermodynamically exergonic but requires high input of cellular energy (ATP)
Is catalyzed by an enzyme that typically contains iron and molybdenum co-factors
All of these answers are true
The tendency of systems to go from a lower state of order to a more organized system is supported by which of the below?
entropy
First Law of Thermodynamics
Second Law of Thermodynamics
Chemiosmotic Theory
None of these answers are correct
Enzyme(s) by which bacteria assimilate gaseous molecular nitrogen is/are...
Nitrogenase
Glutamine synthetase (GS)
Glutamate synthase (GOGAT)
Glutamate degydrogenas (GDH)
Both Nitrogenase and GS
The Ames test...
determines histidine resistace of Salmonella typhimurium
uses Salmonella typhimurium
depends on reversion of histidine auxotrophs to prototrophy
assesses chemical mutagenicity
Bacterial cells are not diploid because...
they do not reproduce sexually
their DNA is single-stranded
their DNA is double-stranded
they use plasmids to reproduce
they usually have only one set of chromosomes
Strains of E. coli with an F-factor that has integrated into the chromosome are known as
Hfr strians
Super males
F+ strains
Episomes
All of these answers are correct
Which of these mechanism(s) do NOT protect nitrogenase from denaturation by molecular oxygen?
fixation of nitrogen under aerobic conditions
heterocysts of cyanobacteria that separate nitrogen fixation from oxygenic photosynthesis
uncoupling of oxidation from phosphorylation in respiratory chain (electron transport system)
leghemoglobin
all of these answers are correct
Housekeeping genes are
constitutively expressed
essential to growth and life of the cell
useful to determine whether a cell is active even without culturing it
none of these answers are correct
Which of the below contributed most to our understanding of "sex" in bacteria?
Joshua Lederberg and Edward Tatum
Paul Berg
Myron Sasser
Max Delbruck and Salvador Luria
The Kardashians
Transfer of gnetic information between prokaryotes that requires direct physical contact between the donor and recipient cells and does NOT require a bacterial virus is called
transformation
transduction
Transcendental Mediation
conjugation
Four- and five-carbon sugars and NADPH, essential for biosynthetic (anabolic) functions, are provided by which pathway?
oxidatie pentose phosphate
Entner-Doudoroff
Tricarboxylic acid cycle
Glycolysis
Embden-Meyerhof, Parnas
Regulation of metabolic pathways within microorganisms is controlled in which of the following ways?
altering activity of key enzymes
regulating biosyntheseis--and thus the amount--of key enzymes
induction and regression of genes
feedback inhibition of key enzymes by end products of a pathway
all of the above
Why did Lederberg and Tatum use multiple auxotrophic mutants, i.e., strains with deficiencies in biosynthetic capabilities in several places, in their experiment that demonstrated conjugation in bacteria?
Each mutation has reversion rate 10*-8 per cell per generation. Thus, 10 in a billion cells will revert to wild-type. By using 3 mutants, the likelihood of all three reverting to wild type is infinitesimally small
They had a lot of auxotrophs in their culture collection
To prove the Mobilome
They were sex addicts
Positive control of gene transcription involves
a regulator protein binding to the DNA operon.
interaction of a regulator protein with DNA that is not a cestron
enhancement of transcription effieceny
suppression of trascription efficiency
All except D
A regulator protein binding to the DNA operon
interaction of a regulator protein with DNA that is not a cistron
enhancement of transcription efficiency
Specific regulatory interaction between proteins and DNA
is common and occurs in all domains in life
is restricted to only Domain Bacteria
is restricted to only Domain Eukarya
is restricted to only Domain Archaea
is restricted to only the prokaryotic domains of Bacteria and Archaea
Genomes of Domain Bacteria...
are haploid.
typically consist of one chromosome.
are covalently closed circular DNA.
may be composed of single-stranded DNA.
Nonsense-supressor mutations...
allow a translation stop codon to be ignored.
require a change in tRNA specificity
restore in the original, wild phenotype
result in substitution of an amino acid into the position specified by the stop codon in the mRNA
Plasmid copy number is which of the below?
The same as chromosomal copy number.
The ratio between the numbers of a specific plasmid inside a bacterial cell and the number of chromosomes.
The total copies of a plasmid in a single cell.
How efficiently a plasmid is copied during cell division.
The number of genes carried on each plasmid
Nitrogenase...
is an enzyme
is common in Domain Eukarya
may catalyze reduction of substrates other than nitrogen gas
is highly conserved in Domains Bacteria and Archaea
The use of terminal electron acceptors other than molecular oxygen at the end of an electron transport chain is...
anaerobic respiration
common in heterotrophic macroorganisms including humans
assiilatory nitrate reduction
aerobic respiration
Which bacteriophage is the model for specialized transduction?
Coliphage Lambda (a phage that attacks E. coli)
coliphage 42
T-even coliphage
General transducing phages
The rolling circle mechanism of DNA replication is utilized...
during conjugative trasfer of DNA into an F- recipient
during replication of DNA of some viruses
during most replication of bacterial chromosomes
by Eukarya
What principal metabolic advantage does fermentation confer to the cell?
Produces useful metabolic byproducts such as ethanol, acetone, lactic acid
Generates a prodigious quantity of ATP
oxidizes reduced electron carriers such as NADH
makes alcoholic beverages and cheeses that make people happy
Which of the below mapping methods will give information on the polar relationship of two genes, e.g., whether gene B is between genes A and C?
co-transformation
co-trasduction
interrupted conjugation
sequencing of DNA bases
The uncoupling of oxidation from phosphorylation during trasport of electrons via an electron trasport system to a terminal electron acceptor
occurs in some natural systems
can be experimentally induced with certain chemicals
results in generation of no ATP
produces heat
The capability of a bacterial strain or species to take up naked DNA is called
competence
fertility
promiscuity
trasduction
lysogeny
Which possible fates for DNA that has been introduced (exogenote) into a new host cell result in the MOST-stable transfer into future generations of the recipient cell?
Recombination with the endogenote
Digestion catalyzed by host enzymes
Formation of a partial diploid cell
Formation of partial diploid clone
The most abundant single protein in the biosphere is
a key enzyme of the Calvin-Benson-Bassham cycle
RuBisCO
pyruvate dehydrogenase
nitrogenase
Okasaki fragments
are proteins
encode housekeeping functions for the cell
are delicious but expensive appetizers at Japenese restaurants
accommodate the fact that DNA polymerase must synthesize the complementary new strand
A metabolic pathway that fixes carbon dioxide into an organic molecule but does not support autotrophic growth is
the reductive pentose phosphate cycle
an anaplerotic reaction
the reverse tricarboxylic acid cycle
the acetyl-CoA pathway
Who was curator for the genetic map of Escherichia coli for many years?
Martha Hershey and Alred Chase
Avery, ClLeod and McCarty
Barbara Bachman
Barbara McClintock
Britney Spears
For this course, we have adopted which terminology as our definition of a "gene?"
DNA polynucleotide sequence that codes for a gene product, e.g., protein, tRNA, rRNA
Cistron
any DNA in a bacterial chromosome or plasmid
a DNA sequence with a specific start and end
Which of the below used radioisotopes to demonstrate that the DNA and not the protein components of bacteriophages directed infection of the host cell?
Avery, MacLeod, and McCarty
Hershey and Chase
Griffith
Watson and Crick
Gilbert and Sanger
Auxotrophic mutant bacteria
have the biosynthetic capability of the "wild type" e.g. typical bacteria of that species
may undergo reversion to their prototrophic forms
are resistant to multiple antibiotics
are able to obtain all their caron requirement by fixing carbon dioxide
Which pathway of glucose catabolism is found only in prokaryotic microorganisms
Embden-Myerhof-Parnas
Calvin cycle
Oxidative Pentose Phosphate
Nitrogen fixation
Who of belaw developed a "chemiosmotic" theory that provided a unified mechanism for how ATP was made during respiration and in the light reactions of photosynthesis?
Peter Mitchell
Louis Pasteur
Woese, Falkow, Berg
Singer, Nicholson
Embden, Meyerhof, Parnas
Small Interfering, siRNA, or "Silencer RNA" is used to
suppress antibiotic resistant mutants
suppress expression of specific genes
select auxotrophic mutants
override stop codons
provide a mechanism for site-specific mutagenesis
Who won the Nobel for discovering transposons
Martha Hershey and Alfred Chase
Avery, McLeod and McCarty
Batman and Robin
Which group below has a specialized cell that compartmentalizes nitrogen fixation and sequesters it from oxygenic photosynthesis
filimentous cyanobacteria
purple non-sulfer bacteria
single-celled cyanobacteria
green sulfur bacteria
purple sulfur bacteria
The principle that spontaneous mutations in bacteria are rare and random
was supported by a fluctuation analysis experiment
was demonstrated by Max Delbruck and Salvador Luria
was demonstrated by using Poisson Distribution
was supported by following acquistition of mutant characteristics during the growth of E. coli in the absence of selection pressures
Under optimal conditions, the complete transfer of the entire chromosome during an Hfr x F- mating between two strains of E. coli takes approximately 100 10 200 50 20( 100, 10, 200, 50, 20 ) minutes.
Mutants of bacteria that are defectiv in biosynthetic capability relative to the wild type can be selected using which of the below?
The Ames test
The auxotrophic-mutant rejection protocol
The Heimlich Maneuver
Use of penicillin counter-selection against prototrophs
Replica plating
Which of the below are/were major player(s) in our understanding of biological nitrogen fixation?
Robert Burris
Harold Evans
Arto Virtannen
Carnahan and ortenson
Which of the below discovered and experimentally demonstrated that a non-living "transforming" material could change an avirulent strain of a bacterium into a virulent, pathogenic microorganism?
Fred Griffith
Sulfanilamide...
is a chemotherapeutic agent
competes with PABA (para-aminobenzoic acid) for an active site of an enzyme
is an antibiotic
stops transcription in bacteria
To what does the term "bacteroid" refer?
bacterial cells within genera Rhizobium or Bradyrhizobium that are symbiotic with leguminous plants
a prokaryote with characteristics similar to both Bacteria and Archaea
a prokaryotic bacterial cell with characteristics similar to those of eukaryotic cells
prokaryotic symbionts that a bacterium-like bacterium found on planets other than Earth
How do bacteroids differ from the free-living bacteria?
They are symbiotic form of genera Rhizobium or Bradyrhizobium with luminous plants
They cooperate with a plant host in producing legheoglobin
They reduce diatomic nitrogen gas to ammonia
A bacterium experienceing a severe amino acid shortage
may exhibit Stringent Response
will contain elevated levels of ppGpp
will continue biosynthesis of amino acids
will have a high level of uncharged tRNA
will have all of the listed properties
Which pathway produces the most ATP?
Embden-Meyerhof-Pamas
Oxidative Pentose Phosphate Pathway
Electron transport chains coupled to chemiosmosis
Who wrote a treatise on the "mobilome"--emphasizing horizontal gene transfer in bacteria
Tamar Barkay
Carl Woese and George Fox
What is the principal Domain of biological organisms within which Operon Theory was developed?
E. coli
Fungi
Eukarya
Archaea
Bacteria
Which Biological Domains apply to the below...
Escherichia coli = Bacteria
Cyanobacteria = Bacteria
Saccharomyces cerevisiae = Eukarya
Cyanobacteria = Archaea
The use of nitrate as a source of nitrogen to build cells is
assimilatory nitrate reduction
reduction of nitrate to ammonia, whcih is then incorporated into amino acids
nitrate respiration
denitrification
Transposons used as mutagens
alkylate (e.g., methylate) nitrogen bases of DNA
create thymidine dimers
distort the DNA backbone and cause reading frameshifts
interupt a gene by inserting into it
Which mechanism(s) may protect nitrogenase from denaturation by molecular oxygen?
uncoupling of oxidation from posphorylation in respiratory chain (electron trasport system
The Calvin-Benson-Bassam cycle
catalyzes the oxidation of CO2
has metabolic intermediates in common with the oxidative pentose phosphate pathway
carboxylates the sugar ribulose 1.5-bisphosphate
is found in both eukaryotic and prokarotic domains of life
The physiological function of anaplerotic CO2 fixation pathways is
to reoxidize NADH
to support autotrophic growth
to replenish 4-carbon compounds such as oxaloacetate in the TCA cycle
to reverse the TCA cycle
Which of the below groups includes a genus name that is NOT a diazotroph?
Escherichia, Fungi
Rhizobium, Sinorhizobium
Clostridium, Klebsiella
Azotobacter, Anabaena
Bradyrhizobium, Spirillum
Lectins
are proteins with an affinity for monosaccharide residues
may be used for ABO-typing of blood
are involved in host-plant selection for nitrogen-fixing symbioses between bacteria and legumes
are produced by legumes
The key enzyme(s) by which bacteria assimilate relatively-LOW concentrations of ammonia is/are
glutamine synthetase
glutamate synthase
glutamate dehudrogenase or other amino acid dehydrogenases
Which of the below enzymes change the covalent structure of DNA?
DNA polymerase III
DNA ligase
DNA gyrase
DNA helicase
Who performed experiments using "fluctuation analysis" and Poisson distribution characterizing spontaneous mutations in bacteria?
Lois Pasteur
Joshua Lederberg
Robert Koch and Louis Pasteur
Griffith, Avery McLeod and McCarty
Early, seminal experiments that distinguished between enetic exchange mechanisms of bacteria that require physical contact and those that do not employed which of the below?
auxotrophic mutants
U-tube with sintered glass
strains of bacteria with multiple biosynthetic deficiencies
Catabolism of a protein bhy any organism requires which first step?
hydrolysis of the polypeptide to amino acids
deamination
breakdown to glucose
"Positive control" regulatory mechanisms include
catabolite repression
repression/co-repression
inducible operons
attenuation
What is the utility of the Ames test?
Drug resistance of Salmonella typhimurium may be determined
Salmonella typhimurium mutation rate may be determined
Genes defective in histidine biosynthesis may be corrected
Repair of auxotrophic mutants is accomplished
an index of potential carcinogenicity of a chemical may be estimated
Batch-growth kinetics of E. coli grown on lactose and glucose hat become exponential pause for a second lag phase, and then proceed to a second logarithmic phase are
a result of a positive-control regulatory meechanism
a result of a microbe's "preference"in carbon source
a result of a mechanism in which cyclic AMP interacts with an allosteric protein
termed "diauxie" or diauxic growth
Regulaion by attenuation requires tight coupling between transcription and translation and, therefore, occurs in
eukaryotes
prokaryotes
fungi and plants
algae
protozoa
The theoretical construct describing transfer of information between macromolecules within cells is known as
trascriptomics
central dogma
genomics
proteomics
bioinformatics
A contiguous series of genes (cistrons) under transcriptional control of a single operator siteand regulatory protein is known as
a regulon
a transcription
a modulon
a transposon
an operon
Regulation by attenuation occurs commonly in which kind of operons?
Lac and other sugar-metabolizing operons
nitrogen fixation operons
Housekeeping gene operons
diauxic operons
amino acid biosynthesis operons
Who was awarded the Nobel Prize for elucidating transcriptional regulation in bacteria?
Francois Jacob, Andre L'Woff, Jacques Monod
Joshuaa Lederberg
Which of the below regions of DNA within an operon are NOT genes/cistrons?
operator
promoter
regulator
Inducible operons
control transcription of genes with catabolic function
control transcription of genes with anabolic/biosynthetic function
control transcription of genes with "food" acquisition and digestive function
Which are cistrons within the Trp operon?
control transcription of genes with catabolic fuction
TrpE, TrpD, Trp C, TrpB, TrpA
LacZ, LacY, LacA
Lower gastrointestinal tracts of vertebrates are anaerobic. Which metabolic pathway(s) is/are responsible for flatulence?
fermentation
oxygenic photosynthesis
anoxygenic photosynthesis
TCA cycle
The "chemiosmotic theory" of oxidative phosphorylation...
provides a unified mechanism for how ATP is made during both aerobic and anaerobic respiration relevant to ALL biological Domains
depens on electron transport chains imbedded in an intact plasma- (cytoplasmic) or mitochondrial-membrane
explains "photophosphorylation" during the light reactions of phoosynthesis
won the Nobel Prize for Peter Mitchell
Which molecular regulatory mechanism(s) allow a bacterium to "decide" whether to use a "preferred" carbon substrate or not?
repression/corepression
Mutation has been defined as...
a stable, heritable change in the DNA sequence of bases
a "genetic change that breeds true"
changes in the phenotype of an organism
Which is the correct sequence (in direction of transcription) of genes and regulatory sites in the Lac operon?
I-O-P-Z-Y-A
I-P-Z-Y-A
P-O-LEADER-E-D-C-B-A
Z-Y-A-P-O-I
LEADER-E-D-C-B-A-P-O
