Deck 8: Major Shifts in Bacterial Transcription

Question 1

Which of the following conditions does not lead to a change in gene expression patterns in bacterial cells?

A)sporulation
B)heat shock
C)nutrient availability
D)nitrogen deprivation
E)none of the choices are correct.

Answer 1

E

Question 2

Which of the following is involved in maintaining lysogeny in $\lambda$ phage?

A)P_RE
B)P_RM
C)P_RL
D)P_RO
E)all of the choices are correct.

Answer 2

P_RM

Question 3

Which of the following sigma specificity factors is involved in middle gene transcription during SPO1 phage infection of bacteria?

A)gp33
B)gp28
C)gp34
D)gp43
E)host sigma

Answer 3

B

Question 4

When a $\lambda$ lysogen suffers DNA damage,it induces the ____________ response.

Question 5

An experiment is planned to look at the transcription start site for the spoIID gene during sporulation.Which of the following techniques would yield the most information in this experiment?

A)southern analysis
B)northern anlaysis
C)S1 mapping
D)run-on assays
E)DNAse footprinting

Question 6

Which of the following explains the events in late stage T4 infection in bacteria?

A)The host sigma factor specifies transcription of genes.
B)There is a high level of transcription of host genes.
C)Host polymerase holoenzyme directs transcription.
D)The host core enzyme participates in transcription conjunction with phage-encoded specificity factors.
E)All of the choices are correct.

Question 7

Which of the following statements is true about the cro gene?

A)It must be stimulated during lysogeny.
B)Its product promotes repressor activity.
C)cro repression is important to lysogeny.
D)It is adjacent to the cIII gene.
E)It must be stimulated during lysogeny and its product promotes repressor activity are correct.

Question 8

Which of the following operators is a target of cI gene production?

A)O_R1
B)O_R2
C)O_L1
D)O_L2
E)all of the choices are correct.

Question 9

Which of the following is a possible mechanism for the action of NusA in termination?

A)It binds to the RNA polymerase causing it to stall.
B)It stimulates termination at intrinsic terminator by facilitating hairpin loop formation.
C)It binds to NusB to promote detachment of the RNA polymerase for the DNA template.
D)It interacts with S10 to promote dissociation of the RNA polymerase.
E)It binds to the RNA polymerase causing it to stall and it stimulates termination at intrinsic terminator by facilitating hairpin loop formation.

Question 10

Which of the following proteins is not involved the lytic phase of $\lambda$ infection of bacteria?

A)CIII
B)S10
C)NusA
D)NusG
E)NusB

Question 11

Which of the following is true about the early phase of T7 infection of bacteria?

A)Class II genes are the first to be transcribed.
B)The host polymerase transcribes class II genes.
C)The phage-encoded polymerase transcribes the class I phage genes.
D)Class I genes are the first to be transcribed.
E)All of the choices are correct.

Question 12

Which of the following is true about the interaction with the $\lambda$ repressor and RNA polymerase at P_RM?

A)Interaction between repressor and polymerase is essential for activation of transcription.
B)Interaction involves region 4 of $\sigma$ -factor.
C)Interaction can be disrupted by the binding of CIII.
D)Interaction between repressor and polymerase is essential for activation of transcription and interaction involves region 4 of $\sigma$ -factor are correct.
E)Interaction between repressor and polymerase is essential for activation of transcription and interaction can be disrupted by the binding of CIII are correct.

Question 13

Predict the outcome of the removal of the N gene from the DNA sequence of the $\lambda$ phage:

A)lysogenic cycle will be induced.
B)entry into the bacterial host will be blocked.
C)antitermination will be affected.
D)transcription from the left promoter will be interrupted.
E)antitermination will be affected and transcription from the left promoter will be interrupted are correct.

Question 14

During an experiment to study the rate of infection of bacteria with T4,the bacterial cultures were accidentally exposed to a UV light source.Which of the following would be expected for this exposure?

A)recA gene is turned off.
B)Coprotease activity in RecA protein is activated.
C)SOS response is induced.
D)Coprotease activity in RecA protein is activated and SOS response is induced are correct.
E)recA gene is turned off and coprotease activity in RecA protein is activated are correct.

Question 15

___________ ____________ bind to unfolded proteins and help them to fold properly.

Question 16

P_RE is the promoter used to establish _____________ in $\lambda$ page.

Question 17

Which of the following is an incorrect statement regarding antitermination?

A)N is involved in termination of the later genes during l phage infection.
B)Antitermination in the l late region requires Q.
C)Five proteins collaborate in antitermination in the l immediate early gene terminators.
D)Both N is involved in termination of the later genes during l phage infection and Antitermination in the l late region requires Q are false.
E)N is involved in termination of the later genes during l phage infection,Antitermination in the l late region requires Q,and Five proteins collaborate in antitermination in the l immediate early gene terminators are false.

Question 18

O,P,S,and R genes are part of the lambda phage genome.A new clone of lambda was constructed that lacked the O and P region.Which of the following would be observed if this new clone were used to infect bacteria?

A)The clone would not enter the cell.
B)The clone would be destroyed by the bacterial host.
C)Replication of this would be impaired in the lytic phase.
D)A rapid burst of replication would occur.
E)The clone would not enter the cell and replication of this would be impaired in the lytic phase are correct.

Question 19

Which of the following is a target of the Cro protein?

A)OR2
B)OR3
C)OL3
D)OR2 and OR3
E)OR3 and OL3

Question 20

_________________ suppression occurs when a mutation in one gene suppresses the mutation in another gene.

Question 21

Transcription in eukaryotes is mediated by sigma factors.

Question 22

Hairpin formation is necessary for ____________________.

Question 23

Lysogeny is established in the production of sufficient repressor to bind to early operators and prevent further early gene synthesis.

Question 24

When phage infects a bacterium,it usually subverts the host's transcription machinery to use as its own.

Question 25

UV radiation can trigger the lytic cycle in $\lambda$ phage.

Question 26

Transcriptional changes that occur when organisms respond to environmental changes are in part due to changes in RNA polymerase.

Question 27

T7 phage encodes a new RNA polymerase for use in the later stages of its bacterial host.

Question 28

Heat shock genes encode proteins that lead to the rapid death of cells when they are exposed to heat.