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During the early stages of sporulation in Bacillus subtilis,________ is active in the forespore and ________ is active in the mother cell.


A) σ\sigma E; σ\sigma F
B) σ\sigma K; σ\sigma F
C) σ\sigma F; σ\sigma K
D) σ\sigma F; σ\sigma E

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Acylhomoserine lactones used in quorum sensing regulate their own synthesis by a(n) ____________ system.


A) riboswitch
B) antisense
C) catabolite repression
D) autoinduction

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D

Two-component signal transduction systems are found in the Bacteria,but not in Archaea.

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Guanine tetraphosphate (ppGpp) is particularly associated with which process?


A) Spore formation in Bacillus
B) Chemiosmosis in Paracoccus
C) Stringent response in Escherichia
D) Quorum sensing in Vibrio

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What term describes a set of genes that is controlled by a common regulatory protein?


A) Codon
B) Regulon
C) Transcription
D) Kinase

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If autophosphorylation of CheA protein does not occur,then Escherichia coli cells must be


A) in a gradient of a chemoattractant.
B) in a gradient of a chemorepellant.
C) tumbling.
D) rotating flagella clockwise.

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Small RNAs that regulate translation by binding to the leader region of mRNAs are called antisense RNAs.

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Which is false regarding the two-component regulatory system in bacteria?


A) The system involves a sensor kinase and a response regulator.
B) The sensor kinase is phosphorylated by the response regulator when the extracellular environment changes.
C) Regulation of OmpF and OmpC porin proteins in
D) One part of the system is exposed to the external cellular environment while another part is exposed to the cytoplasm.
E) coli is modulated by this type of system.

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The site on the DNA to which a repressor protein binds is the __________.


A) operon
B) operator
C) promoter
D) regulator

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In which situation might methylation of membrane proteins in Escherichia coli initiate a phosphorelay system that evokes clockwise rotation of flagella?


A) Presence of a chemorepellent in the extracellular environment.
B) Change in environmental osmotic pressure.
C) Utilization of lactose due during diauxic growth.
D) Cellular population reaches a quorum.

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Which of the following is an example of gene regulation at the posttranslational level?


A) Alteration of protein structure
B) Early termination of an mRNA transcript
C) Initiation of protein synthesis
D) Prevention of RNA synthesis

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In some circumstances,when two different carbon sources are available,growth will occur first using one carbon source,then after a short lag period,growth will resume using the second carbon source.This process is called __________ growth.


A) alternating
B) bimorphic
C) diauxic
D) dimorphic

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The


A) one
B) two
C) three
D) four
E) coli lac operon has ________ operator sequences.

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The activity of adenyl cyclase is influenced by


A) the phosphotransferase system.
B) the presence of lactose in the environment.
C) homoserine lactones.
D) None of the choices are correct.

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A

In catabolite repression systems of some Gram-positive bacteria,such as Bacillus subtilis,transcription of catabolic operons is regulated by CcpaA (catabolite control protein A) rather than cAMP.Propose a hypothesis to explain the preferential use of glucose in the presence of a second sugar such as sucrose by Bacillus subtilis.


A) CcpaA acts as a repressor of sucrose operon genes in Bacillus subtilis when both sugars are present.
B) CcpaA acts as an inducer of sucrose operon genes in Bacillus subtilis when both sugars are present.
C) CcpaA acts as a repressor of sucrose operon genes in Bacillus subtilis when lactose,but not glucose,is present.
D) CcpaA acts as an inducer of sucrose operon genes in Bacillus subtilis when glucose,but not lactose,is present.

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In terms of global gene regulation,which of the following molecules is most similar to c-di-GMP and cAMP?


A) ppGpp
B) rRNA
C) ATP
D) EnvZ

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A

Riboswitches regulate transcription,rather than translation,in cells.

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Scientists first focused on gene regulation at the level of translation,rather than transcription,because more was known about protein than nucleic acids at the time.

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When a repressor binds to the operator site on the DNA it normally


A) inhibits the initiation of transcription.
B) reduces the rate of transcription.
C) terminates transcription that has already been initiated.
D) has no effect on transcription.

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If a set of genes is repressed in the presence of the controlling substance,it is referred to as __________ control.

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