124 Cards in this Set
| Front | Back |
|---|---|
|
The E coli chromosome is organized into
|
40-50 chromosome domains
|
|
What are chromosome domains
|
domains are relaxed cytoplasmic loops of chromosome
|
|
What are domains functions
|
they help to prevent the loss of supercoiling along the whole chromosome
|
|
What are domains involved in?
|
chromosome replication, transcription
|
|
what are transposons
|
they are DNA sequences which are capable of changing their location in a host genome
|
|
What are the 2 types of transposons?
|
1. replicative ( one remains at the origin site, while the second copy is inserted)
2. non replicative: the transposon is physically removed from its original genome site and reintegrated into the genome at a new site
|
|
what is an operon
|
it is a cluster of multiple genes grouped together into a single transcriptional unit, under the control of a single promoter
|
|
What is promoter strength matched to?
|
the amount of gene product needed by the cell
|
|
what type of control is the lac operon under?
|
dynamic control
|
|
transduction
|
is a method of horizontal gene transfer, via a replicating virus or bacteriophage
|
|
the first E. coli map was created using?
|
Hfr conjugation and phage transduction
|
|
concatemer
|
Is a DNA molecule containing multiple, contiguous copies of the phage genome
|
|
replica plating allows for
|
selection and scoring of mutants as well as recombinants from gene transfer events
|
|
transduction mapping can be used to
|
determine which gene is "in between" the other 2
|
|
transduction mapping involves 3 steps
|
1. crossing
2. selection
3. scoring
|
|
specialized transduction results from
|
aberrant excision of an integrated prophage
|
|
specialized transduction generates
|
partial diploid (merozygotes)
|
|
virulence conversion
|
bacteria can induce functional toxin gene to a fox-cell via specific transduction
|
|
horizontal gene transfer (HGT) in prokaryotes is...
|
directional, linear, and incomplete
|
|
Free-swimming chemotactic bacteria power their transmembrane flagella motors with ATP.
|
F
|
|
Repressor proteins bind to newly synthesized mRNA sequences and induce polymerase dissociation.
|
False; Page 220 binds to DNA.
|
|
1. When a chemotactic E.coli cell senses attractant concentration is decreasing- tumbling frequency increases.
|
False, directly proportional
|
|
Host legume symbiosome cells produce leghemoglobin molecules to maintain a low oxygen concentrations for Rhizobium bacteriods.
|
T
|
|
Since Hfr formation is reversible, every Hfr or F+ culture is a mixture of both
|
T
|
|
Repressible prokaryotic gene regulation systems use effectors to stop gene transcription.
|
T
|
|
Anaerobic niches in marine or freshwater sediments are typically devoid of significant organic material, and therefore facilitate colonization by carbon and nitrogen fixing organisms only.
|
FALSE. Anaerobic niches fall into two principal categories;
– the intestinal tracts of animals.
– marine or freshwater sediments rich in organic
material.
|
|
Conjugation can transfer DNA from prokaryotic cells across great genetic distances.
|
FALSE:
Prokaryotic conjugative plasmids have been shown to be transferred across great evolutionary distances - as in this example- from prokaryotic bacteria cells to eukaryotic plant cells
|
|
Most lichens are comprised of a single fungus in symbiosis with a single phototrophic organism.
|
True
|
|
Supercoiling is essential to pack the chromosome into a small volume.
|
True; Lecture 14 Slide 2.
|
|
A modulon is a group of operons controlled by the same global control system.
|
True; Modulon - a group of operons, each with unique
transcription control, sharing a common, overriding,
secondary transcriptional control system regulating
cumulative expression of all operons in response to an
environmental change.
|
|
Purple non-sulfur bacteria gron in stagnant, anoxic waters using organic sulfur for energy,
|
False; Uses hydrogen sulfide for energy
|
|
Mycorrhizial symbionts provide water, minerals and protection to plant root cells.
|
true
|
|
Prokaryotic metabolic processes return nutrients from the sea to the land.
|
????
|
|
Most prokaryotic transcriptional units have one or more regulatory sites controlling the rate of transcription.
|
T
|
|
A transposon is a DNA sequence capable of changing its location in a host genome.
|
T
|
|
Prokaryotic cells exclusively convert nitrates to N2 gas.
|
T
|
|
The B. anthracis vaccine was developed by growing a culture of B. anthraces cells at lower temperatures than normal.
|
False; Higher
|
|
Specialized transduction is the result of a rare mistake of prophage excision.
|
T
|
|
A nucleotide base sequence shares positional homology with another sequence when both sets of bases are descended from the same base in a common ancestor.
|
True
|
|
In many symbioses the prokaryote partner provides fixed nitrogen.
|
True
|
|
Rho-independent transcriptional termination requires formation of a stem-loop secondary structure in the developing mRNA coupled with a GC-rich region of DNA for successful dissociation.
|
False, A-U base pairs
|
|
Transformation is when DNA - released by a competent cell - is taken up by a donor cell
|
F, by the recipient cell
|
|
The PatS oligopeptide is produced by the heterocyst at a constant rate.
|
T
|
|
Weak promoters are recognized less effectively by RNA polymerases and as a result are good for operons requiring dynamic control
|
true
|
|
Geothermal vent ecosystems are based on bacterial chemoheterotrophic symbionts
|
??
|
|
Is genetic information encoded on plasmids essential for cell functions?
|
No, but may confer a selective growth advantage under certain conditions
|
|
Hyperthermophilic bacteria have optimal growth temperatures between 45 and 60 degrees Celsius.
|
FALSE. Optimum growth temperatures in the 70- 85°C range.
|
|
Horizontal gene transfer among distantly related organisms confuses phylogenies.
|
T
|
|
Syntrophy is common in aerobic freshwater ecosystems.
|
False; It is anaerobic freshwater ecosystems
|
|
A Sigma protein equivalent has not been identified in archaea or eukarya.
|
True
|
|
Most prokaryotic genomes are comprised of a "pair of diploid", circular "" chromosomes.
|
False; single, DNA (haploid)
|
|
Odd numbers of crossovers between endo- and exogenous result in recombinant chromosomes.
|
False; Odd numbered results in destruction. Even numbered results in recombinant.
|
|
Spirochetes are characterized by their periplasmic endoflagella.
|
T
|
|
Quorum sensing induces expression of operons involved in
"microbial metabolism, DNA replication and cell wall synthesis."
|
??False; biofilm, surfactant and antibiotic production
|
|
The spoA cascade is initiated by a series of sigma factors
|
?
|
|
High internal glucose-6-P concentration generates low cAMP levels.
|
TRUE. High internal
glucose levels cause the adenyl cyclase enzyme to dephosphorylate cAMP molecules -
decreasing cAMP levels.
|
|
Antisense RNA anneals/binds to complementary DNA, disrupting polymerase association and terminating transcription.
|
false; translation
|
|
Three-point genetic crosses require triple-phenotype bacterial strains.
|
?False; Its genotypic
|
|
Carbon dioxide is a major end product of many prokaryotic fermentations.
|
?True
|
|
Competence factor is only produced and excreted by cells at a sufficiently high cell density.
|
?False
|
|
Prokaryotic genes are typically organized into operons.
|
?true
|
|
Deinococci stain as if they are gram positive due to a thick peptidoglycan layer despite not being gram-positive bacteria.
|
TRUE. The deinococcal Gram-negative cell envelope
structure contains a thick peptidoglycan layer
causing cells to stain Gram-positive
|
|
Interrupted mating experiments allow scientists to create linkage maps of relative gene distance by exploiting bacterial conjugation
|
True
|
|
Microbes unable to detoxify oxygen radicals would exhibit negative aerotaxis.
|
True
|
|
The Planctomyces are a group of obligate, intracellular parasites.
|
FALSE. Planctomyces group
Aquatic and marine prokaryotes.
Most are unicellular budding organisms.
The only bacterial lineage to
lack peptidoglycan entirely,
having a protein cell wall.
|
|
Neutral mutations often result in convergence.
|
False, never result in convergence
|
|
The nitrifying bacteria are mostly obligate chemoautotrophs capable of oxidizing ammonia or nitrite for energy.
|
T
|
|
Negative genetic control uses repressor proteins to turn off gene transcription
|
True
|
|
Charles Darwin first proposed groups of organisms sharing similar features are related by descent from a common ancestor.
|
True
|
|
transmissible plasmids encode special pili bind
|
donor cells to recipient cells
|
|
recipient carrying the same plasmid will not conjugate. This phenomenon is called
|
surface exclusions
|
|
DNA conjugal is simultaneous with
|
plasmid replication for most bacterial plasmids
|
|
transfer and replication is initiated where?
|
at the oriT site
|
|
Three E. Coli fertility (F) types. or what are the three F types in E. coli
|
1. F-: does not have plasmid, but can receive one
2. F+: F plasmids replicates autonomously (by its self)
3: HFr: the F plasmid integrates into the chromosome and can mobilize.
- Since Hfr formation is reversible every Hfr or F+ strain culture is mixture of both
|
|
Inducible prokaryotic operons under negative control have transcription factors requiring effector binding to induce transcription.
|
False, positive control
|
|
Methanogens dominate in freshwater sediments.
|
F??
|
|
Rhizobium bacteriods provide fixed nitrogen for the water fern Azolla, leading to increased rice crop yields.
|
False, the cyanobacterium anabaena and Azolla exist in symbionts in rice paddies
|
|
Oxygen consumption in the animal intestinal tract is entirely due to facultative anaerobes.
|
T
|
|
Oxygen consumption in the animal intestinal tract is entirely due to obligate anaerobes.
|
False; Facultative anaerobes
|
|
Endospores are cryptobiotic – manifesting no measurable living activity.
|
T
|
|
Nitrifying eukaryotes can use nitrite (NO2-) as an electron donor for an aerobic, chemoautotrophic respiration.
|
?
|
|
Transformational competence is regulated by a quorum-sensing mechanism.
|
T lecture 16
|
|
Neutral mutations often result in convergence.
|
FALSE, NEVER result in convergence
|
|
Though prokaryotic organisms are the most abundant organisms on Earth, they do not represent a majority of the Earth's biomass due to the dramatic difference in size between prokaryotes and multicellular eukaryotes.
|
F, they do make up large amount of bio mass
|
|
Lichens are a symbiois between a fungus and the root cells of an angiosperm plant.
|
false
-Lichens are a fungus in symbiosis with a photoautorophic organism
|
|
mycorrhizial fungi are symbionts of
|
angiosperm plant root cells
|
|
Plasmids are present in all archaeal and bacterial species.
|
F
|
|
Cyanobacteria are known for their extreme radiation and ultraviolet (UV) light resistance.
|
F, Deinococci
|
|
Bacterial promoters with consensus base sequences from multiple bacterial promoters are considered ideal.
|
T
|
|
STARI is a red, expanding “bulls eye” lesion around a lone star tick bite caused by Borrelia burgdorferi.
|
F, is NOT caused by BB, nor lyme disease agent, nor rickettsia rickettsii, the RMSF agent. It is not linked to any arthritic or serious neurological symptoms
|
|
The extensive secondary structure in 16S rRNA assists in sequence alignment.
|
T
|
|
High internal glucose-6-P concentration generates low cAMP levels.
|
F, low internal glucose causes increase in cAMP
|
|
Prokaryotic transcription initiation is controlled by allosteric proteins.
|
T
|
|
Continued prokaryotic gene expression requires continuous mRNA transcription.
|
True; Lecture 15
|
|
Quorum sensing allows cells to begin production of certain compounds only upon reaching a certain size.
|
? f?
|
|
Chromosome domains are tightly packed sequences of DNA located between relaxed cytoplasmic loops.
|
FALSE. Domains are relaxed, cytoplasmic
loops of chromosomal DNA
|
|
A symbiotic relationship in which both partners benefit is known as commensal.
|
false- mutualism
|
|
commensalism
|
one partner benefits the others is/are unaffected
|
|
parasitism
|
one benefits at the expense of the other
-the symbiont benefits at the expense of the other
|
|
Free-swimming chemotactic bacteria power their transmembrane flagella using a chemiosmotic gradient.
|
T
|
|
The Volkswagen syndrome explains how secondary structure of a molecule assists with sequence alignment.
|
F
-16s rRNA
|
|
Hyperthermophilic bacteria have optimal growth temperatures between 45 and 60 degrees Celsius.
|
FALSE. Optimum growth temperatures in the 70- 85°C range.
|
|
Plant root cells provide water, minerals and protection to the mycorrhizial symbionts.
|
FALSE. The plant provides carbohydrates
produced by carbon fixation.
The fungus provides surface area for the uptake of
inorganic nutrients and water and protection.
|
|
Mycorrhizial symbionts provide water, minerals and protection to plant root cells.
|
true
|
|
Syntrophy is common in aerobic freshwater ecosystems.
|
False; It is anaerobic freshwater ecosystems
|
|
The rarest recombination event occurs at the lowest frequency in a genetic cross.
|
??t
|
|
The first Bacillus anthracis vaccine strain was developed by Louis Pasteur.
|
T
|
|
Many prokaryotic cells demonstrate negative chemotactic responses away from repellents.
|
T
|
|
Transposons have led to large amounts of "junk" DNA in most prokaryotic genomes.
|
F??
|
|
Directed cell movement in response to light intensity is termed phototaxis.
|
T
|
|
Gram-negative transformation is species specific and uptakes DNA in double-stranded form.
|
True; Lecture 16
|
|
The first E. coli linkage map was created using "massively parallel DNA sequencing."
|
False; Hfr conjugation and phage transduction
|
|
An operon is a single gene controlled by a variety of regulatory elements.
|
F. An operon is a cluster of multiple genes grouped together
into a single transcriptional unit,
under the control of a single promoter.
|
|
Sigma proteins assist RNA polymerase with promoter binding in all prokaryotes and dissociate after transcription initiation.
|
T
|
|
Prokaryotic chromosomes are exclusively diploid.
|
F
|
|
Antisense RNA anneals/binds to complementary mRNA sequences blocking transcription.
|
T
|
|
Repressors and transcription factors sometimes bind at two distant sites forming a DNA loop.
|
T
|
|
The Planctomcyes are mostly unicellular budding bacteria associated with aquatic/marine environments.
|
T
|
|
Phylogeny reflect the history of a single gene across microbial genomes, but other parts of the genome may relate differently due to horizontal gene transfer.
|
T lec 19
|
|
Generalized transducing phage carry both host and virus DNA.
|
F, contain only host DNA led 18 slide 4
|
|
Riftia tube worms fix carbon for bacterial chemoautotroph symbionts who, in turn, provide ammonia, hydrogen sulfide and carbon dioxide from geothermal vents to the Riftia worms.
|
True; Lecture 22.
|
|
Strains of E. coli either contain the F plasmid (F+) or lack the F plasmid (Hfr).
|
F, mixture of both
|
|
Purple sulfur bacteria grown in stagnant, anoxic waters using hydrogen sulfide for energy.
|
T
|
|
Odd numbers of crossovers between endo- and exogenous result in recombinant chromosomes.
|
False; Odd numbered results in destruction. Even numbered results in recombinant.
|
MB 351: TEST 2