Deck 11: Regulation of Gene Expression in Bacteria and Their Viruses

Question 1

A super repressor mutation (I^S)results in:

A)no transcription.
B)inducible transcription.
C)transcription but no translation.
D)no translation.
E)constitutive transcription.

Answer 1

A

Question 2

The lac operon is controlled by:

A)the Lac repressor.
B)attenuation.
C)catabolite activator protein (CAP).
D)the Lac repressor and catabolite activator protein (CAP).
E)the Lac repressor and attenuation.

Answer 2

D

Question 3

Which of the following is an example of a trans-acting factor?

A) $\beta$ -galactosidase
B)operator site
C)lacI repressor protein
D)lactose
E)permease

Answer 3

lacI repressor protein

Question 4

A promoter mutation (P^-)results in:

A)no transcription.
B)inducible transcription.
C)transcription but no translation.
D)no translation.
E)constitutive transcription.

Question 5

DNA-dependent RNA polymerase binds to the:

A)repressor gene.
B)promoter.
C)operator.
D)permease gene.
E)sugar lactose.

Question 6

E.coli bacteria are placed into a medium containing both glucose and lactose.Which of the gene products (i.e.,enzymes)listed below do you predict will be "turned on"?

A) $\beta$ -galactosidase
B)lacI
C)lacP
D)permease
E)None of the answer options are correct.

Question 7

Which of the following is/are NOT part of the lac operon?

A)lacZ
B)lacI
C)lacY
D)lacA
E)All (lacZ,lacI,lacY,and lacA)are part of the lac operon.

Question 8

A partial diploid of genotype I^S P⁺ O⁺ Z⁺ / I⁺ P⁺ O⁺ Z^- will show:

A)inducible production of repressor.
B)inducible production of $\beta$ -galactosidase.
C)constitutive production of $\beta$ -galactosidase.
D)no production of $\beta$ -galactosidase.
E)constitutive production of lactose.

Question 9

A partial diploid of genotype I^- P⁺ O⁺ Z⁺ / I⁺ P⁺ O⁺ Z^- will show:

A)inducible production of repressor.
B)inducible production of $\beta$ -galactosidase.
C)constitutive production of $\beta$ -galactosidase.
D)no production of $\beta$ -galactosidase.
E)constitutive production of lactose.

Question 10

A partial diploid of genotype I⁺ P⁺ O⁺ Z⁺ Y^- / I⁺ P^- O⁺ Z⁺ Y⁺ will show:

A)inducible production of $\beta$ -galactosidase.
B)inducible production of $\beta$ -galactosidase and permease.
C)constitutive production of $\beta$ -galactosidase.
D)constitutive production of $\beta$ -galactosidase and permease.
E)no $\beta$ -galactosidase or acetylase production at all.

Question 11

A constitutive operator mutation (O^c)results in:

A)no transcription.
B)inducible transcription.
C)transcription but no translation.
D)no translation.
E)constitutive transcription.

Question 12

Which of the following is an example of a cis-acting element?

A) $\beta$ -galactosidase
B)operator site
C)lacI repressor protein
D)lactose
E)permease

Question 13

A prokaryotic operon is composed of a series of adjacent genes under the control of:

A)the same promoter.
B)the same operator.
C)an inducible promoter.
D)the same operator and promoter.
E)None of the answer options are correct.

Question 14

The product of the regulator gene of the lac operon is

A)the operator.
B)the inducer.
C)the repressor.
D)the corepressor.
E) $\beta$ -galactosidase.

Question 15

The repression of the transcription of lactose-metabolizing genes in the presence of glucose is an example of:

A)catabolite induction.
B)anabolite induction.
C)anabolite repression.
D)catabolite repression.
E)None of the answer options are correct.

Question 16

The lac repressor (LacI)binds to:

A)lactose and DNA.
B)RNA polymerase.
C)RNA polymerase and DNA.
D) $\beta$ -galactosidase,permease,and transacetylase.
E)RNA and DNA.

Question 17

A null repressor mutation (I^-)results in:

A)no transcription.
B)inducible transcription.
C)transcription but no translation.
D)no translation.
E)constitutive transcription.

Question 18

The enzyme $\beta$ -galactosidase can convert the disaccharide lactose into:

A)allolactose.
B)glucose.
C)allolactose and glucose.
D)allolactose,glucose,and galactose.
E)sucrose and glucose.

Question 19

Which is the synthetic inducer Jacob and Monod used to examine the expression of $\beta$ -galactosidase?

A)allolactose
B)isopropyl- $\beta$ -D-thiogalactoside
C)lactose
D)albumin
E)galactose

Question 20

The lac repressor protein controls expression of the lac operon by binding to the:

A)lac structural genes to repress expression.
B)lacZ and lacY genes only to repress expression.
C)lac operator site to repress expression.
D)lac promoter site to repress expression.
E)All of the answer options are correct.

Question 21

In the presence of the repressor molecule and the absence of free tryptophan,the trp operon is:

A)constitutively transcribed.
B)derepressed.
C)induced.
D)repressed.
E)transcribed but not translated.

Question 22

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-phenotype with respect to $\beta$ -galactosidase synthesis for the partial diploid I⁺ O⁺ Z⁺ / I^- O^C Z^-

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation

Question 23

In the presence of the repressor molecule and free tryptophan,the trp operon is:

A)constitutively transcribed.
B)derepressed.
C)induced.
D)repressed.
E)transcribed but not translated.

Question 24

In the absence of arabinose,the AraC protein represses the ara operon by binding to:

A)araI.
B)araO.
C)araI and araO.
D)araI and araA.
E)araO and araA.

Question 25

The regulation of operon gene expression by attenuator control is commonly found in:

A)glucose utilization pathways.
B)lactose utilization pathways.
C)amino acid biosynthetic pathways.
D)fatty acid biosynthetic pathways.
E)UV-protection responses.

Question 26

Which of the following is/are NOT part of the trp operon?

A)trpR
B)trpE
C)trpC
D)trpA
E)All (trpR,trpE,trpC,and trpA)are part of the trp operon.

Question 27

The attenuator region (AR)of the trp operon is located:

A)within the promoter region.
B)between the promoter region and the operator site.
C)within the operator site.
D)between the operator site and the first structural gene.
E)after the structural genes.

Question 28

The specific conformation (shape)of DNA binding regulatory proteins is such that these proteins can interact and bind to:

A)specific bases in the DNA through its major grooves.
B)the phosphate backbone in the DNA.
C)other transcription factors that are trans-acting elements.
D)helicase to help induce transcription.
E)specific bases in the DNA through its minor grooves.

Question 29

The trp operon is controlled by:

A)Trp repressor.
B)attenuation.
C)catabolite activator protein (CAP).
D)Trp repressor and catabolite activator protein (CAP).
E)Trp repressor and attenuation.

Question 30

Under conditions where tryptophan is scarce:

A)the attenuator stem-loop structure forms,allowing transcription to continue.
B)the attenuator stem-loop structure forms,terminating transcription.
C)the preemptor stem-loop structure forms,allowing transcription to continue.
D)the preemptor stem-loop structure forms,terminating transcription.
E)None of the answer options are correct.

Question 31

Any regulatory protein that acts by preventing transcription termination is called a:

A)corepressor.
B)coactivator.
C)antiterminator.
D)antipromoter.
E)attenuator.

Question 32

In the bacteriophage $\lambda$ ,cro gene encodes the Cro repressor,which:

A)represses lytic growth and promotes lysogeny.
B)represses lysogeny and permits lytic growth.
C)represses both lytic growth and lysogeny.
D)promotes lysogeny.
E)None of the answer options are correct.

Question 33

In the bacteriophage $\lambda$ ,the mutants cI,cII,and cIII form:

A)form turbid plaques and are able to establish lysogeny.
B)form clear plaques and are unable to establish lysogeny.
C)form turbid plaques and are unable to establish lysogeny.
D)form clear plaques and are able to establish lysogeny.
E)form both clear and turbid plaques.

Question 34

The order of the structural genes controlling the trp operon is:

A)trpE,trpD,trpC,trpB,trpA.
B)trpA,trpC,trpB,trpD,trpE.
C)trpE,trpD,trpC,trpA trpB.
D)trpA,trpB,trpC,trpD,trpE.
E)None of the answer options are correct.

Question 35

In the presence of abundant tryptophan:

A)the attenuator stem-loop structure forms,allowing transcription to continue.
B)the attenuator stem-loop structure forms,terminating transcription.
C)the preemptor stem-loop structure forms,allowing transcription to continue.
D)the preemptor stem-loop structure forms,terminating transcription.
E)None of the answer options are correct.

Question 36

In the bacteriophage $\lambda$ ,the N gene encodes:

A)an alpha repressor.
B)a positive regulator.
C)a Cro repressor.
D)a lac repressor.
E)a negative regulator.

Question 37

In the bacteriophage $\lambda$ ,the cI gene encodes the $\lambda$ repressor,which:

A)represses lytic growth and promotes lysogeny.
B)represses lysogeny and permits lytic growth.
C)represses both lytic growth and lysogeny.
D)promotes lytic growth.
E)None of the answer options are correct.

Question 38

In Bacillus,the presence of alternate forms of which molecule is responsible for the control of large numbers of genes?

A)DNA dependent RNA polymerase
B)TFII
C)σ factor
D)Trp repressor
E)Operator protein

Question 39

RNA polymerase binds to the promoter and transcribes the ara operon.In the presence of arabinose,both the CAP-cAMP complex and the AraC-arabinose complex must bind to:

A)araO.
B)araI.
C)araA.
D)araB.
E)araD.

Question 40

Which of the following DNA-binding proteins contain a helix-turn-helix domain?

A)LacI repressor
B)TrpR repressor
C)AraC activator
D) $\lambda$ and Cro repressor
E)All of the answer options are correct.

Question 41

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-small molecules that bind to regulatory molecule,such as repressor

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation

Question 42

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-phenotype of trp R⁺ O⁺ S⁺ in the presence of tryptophan

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation

Question 43

Give the levels of $\beta$ -galactosidase activity ( $\textbf{ high}$ or $\textbf{ low }$ )expected for the following partial diploids for the lac operon.
$\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$$\begin{array}{ll} \text {Lactose absent}& \text {Lactose present}\end{array}$

a) $I ^ { + } P ^ { + } O ^ { + } Z ^ { - } / I ^ { + } P ^- O ^ { + } Z ^ { + }$
b) $I ^ { + } P ^ { + } O ^ { + } Z ^ { - } / I ^ { - } P ^ { + } O ^ { + } Z ^ { + }$
c) $I ^ { + } P ^ { + } O ^ { \mathrm { C } } Z ^ { - } / I ^ { + } P ^ { + } O ^ { + } Z ^ { + }$
d) $I^- P ^ { + } O ^ { \mathrm { C } } Z ^ { + } / I ^ { + } P ^ { + } O ^ { + } Z ^ { + }$
e) $I ^ { + } P ^ { + } O ^ { \mathrm { C } } Z ^ { + } / I ^ { S } P ^ { + } O ^ { + } Z ^ { + }$

Question 44

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-phenotype of I⁺ O⁺ Z^- / I⁺ O^C Z⁺

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation

Question 45

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-type of operons responding to catabolite repression (glucose effect)

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation

Question 46

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-phenotype with respect to the synthesis of tryptophan enzymes in the trp operon trp R⁺ O^C S⁺ (trpR codes for repressor;S = structural gene)

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation

Question 47

Predict whether $\beta$ -galactosidase will be produced by the following E.coli strains under the conditions noted.The diploid genotypes represent F' (lac)strains.Use + to indicate that the enzyme is synthesized at greater than basal levels,and 0 to indicate that the enzyme is not synthesized.
$\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$$\begin{array}{ll} \quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\text {Lactose absent}& \text {Lactose present}\end{array}$

a) $I ^ { + } P ^ { + } O ^ { + } Z ^ { + }$
b) $\mathrm { I } ^ { - } \mathrm { P } ^ { + } \mathrm { O } ^ { + } \mathrm { Z } ^ { + }$
c) $\mathrm { I } ^ { + } \mathrm { P } ^ { + } \mathrm { O } ^ { \mathrm { C } } \mathrm { Z } ^ { + }$
d) $I ^ { - } P ^ { + } O ^ { \mathrm { C } } Z ^ { + }$
e) $I ^ - P ^ { + } O ^ { \mathrm { C } } Z ^ { - }$
f) $\mathrm { I } ^ { + } \mathrm { P } ^ { + } \mathrm { O } ^ { + } \mathrm { Z } ^ { - }$
?) $\mathrm { I } ^ { + } \mathrm { P } ^ { + } \mathrm { O } ^ { \mathrm { C } } \mathrm { Z } ^ { - } / \mathrm { I } ^ { + } \mathrm { P } ^ { + } \mathrm { O } ^ { + } \mathrm { Z } ^ { + }$
h) $I ^ { + } P ^ { + } O ^ { + } Z ^ { - } / I ^ { + } P ^ { + } O ^ { \mathrm { C } } Z ^ { + }$
i) $I ^ { + } P ^ { + } O ^ { + } Z ^ { - } / I ^ { - } P ^ { + } O ^ { + } Z ^ { + }$
j) $\mathrm { I } ^ { + } \mathrm { P } ^ { + } \mathrm { O } ^ { + } \mathrm { Z } ^ { + } / \mathrm { I } ^ { - } \mathrm { P } ^ { + } \mathrm { O } ^ { + } \mathrm { Z } ^ { - }$
k) $I ^ { + } P ^ { + } O ^ { \mathrm { C } } Z ^ { - } / I^- P ^ { + } O ^ { + } Z ^ { + }$
1) $I ^ { + } P ^ { + } O ^ { + } Z ^ { - } / I ^ { - } P ^ { + } O ^ { \mathrm { C } } Z ^ { + }$
m) $I ^ { - } P ^ { + } O ^ { + } Z ^ { - } / I^- P ^ { + } O ^ { C } Z ^ { + }$
1) $I ^ { - } P ^ { + } O ^ { \mathrm { C } } Z ^ { - } / I^- P ^ { + } O ^ { + } Z ^ { + }$

Question 48

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-regulatory molecule must be present at site in DNA (such as promoter)so that transcription occurs

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation

Question 49

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-During lytic cycle of lambda phage,genes concerned with DNA replication are transcribed before genes specifying head proteins,which are transcribed before tail proteins.

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation

Question 50

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-mutation that reverses the effect of another mutation at a different site

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation

Question 51

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-regulatory molecule that binds to operator region in DNA

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation

Question 52

Consider an E.coli cell with the following mutations.What effect would each mutation have on the function of the lac operon (assuming no glucose is present)?
a)a mutant lac operator that cannot bind repressor
b)a mutant lac repressor that cannot bind the lac operator
c)a mutant lac repressor that cannot bind to allolactose
d)a mutant lac promoter that cannot bind CAP plus cAMP

Question 53

The lac operon is the classic "inducible system" for gene control,while the trp operon is the classic "repressible system." Arguably,the key difference between these control systems involves the manner in which the repressor proteins control transcription.Compare and contrast the LacI repressor protein with the TrpR repressor protein.

Question 54

Gene regulation in bacteria and bacteriophage utilize the following terminology.Twelve terms are given below (a - l), followed by twelve statements.Write the letter of the correct term.A single letter is sufficient.Not all letters need be used.Some letters may be used more than once.
Term List

-post-translational control of biosynthetic pathway

A)temporal control
B)positive control
C)negative control
D)inducible
E)noninducible
F)repressible
G)constitutive
H)operator
I)repressor
J)effector molecule
K)feedback inhibition
L)suppressor mutation