Deck 29: Transcription and the Regulation of Gene Expression

Question 1

There are 2 consensus sequence elements within the promoter sequence.Which of the following are they?

A)the rho subunit near -10 with a sequence of TATAAT;the sigma subunit containing the consensus TTGACA
B)the Pribnow box near -10 with a sequence of TATAAT;the sigma subunit containing the consensus TTGACA
C)the rho subunit near -10 with a sequence of TATAAT;the Pribnow box containing the consensus TTGACA
D)the Pribnow box near -10 with a sequence of TATAAT;the -35 region containing the consensus TTGACA

Answer 1

D

Question 2

Which of the following subunits in E.coli RNA polymerase is required for recognition of the promoter sequence?

A)a (alpha)
B)b (beta)
C)s (sigma)
D)b ' (beta prime)

Answer 2

C

Question 3

The non-template strand has the same nucleotide sequence and direction as that of the RNA transcript.Which of the following parts of the mRNA encodes the N-terminus of the protein?

A)non-reducing end
B)reducing end
C)3'-end
D)5'-end

Answer 3

D

Question 4

Which of the following is NOT a stage in transcription?

A)binding of RNA polymerase holoenzyme at the promoter sites
B)chain elongation
C)DNase I activity on RNA polymerase/DNA complex
D)initiation of polymerization

Question 5

Operons are regulatory sequences lying adjacent to the DNA being transcribed and are composed of a promoter located next to an operator.Which of the following interacts with and controls the operator?

A)repression protein
B)enhancer protein
C)activator protein
D)regulatory protein

Question 6

Which of the following is NOT a factor or subunit contained within the E.coli RNA polymerase holoenzyme in prokaryotic organisms?

A)r (rho)
B)a (alpha)
C)b (beta)
D)b ' (beta prime)

Question 7

In order for transcription to begin,the DNA-duplex must be "opened" to allow RNA polymerase access to single-stranded template.Which of the following facilitates "opening" of DNA-duplex?

A)high melting temperature,Tm,in the Pribnow box
B)G:C-rich DNA duplex
C)binding of RNA polymerase s-subuni
D)positive supercoiling

Question 8

Which of the following terms is for the specific sequences in DNA that determine intrinsic RNA chain cessation?

A)termination
B)rho binding
C)template binding
D)supercoil

Question 9

Which of the following does single polycistronic mRNA encode for in bacteria?

A)a single enzyme although there are many in the metabolic pathway
B)multiple enzymes of the particular pathway
C)a single mRNA which is split into multiple mRNAs before translation
D)a single peptide with multiple catabolic sites

Question 10

Which of the following factors is an ATP-dependent helicase utilized in one of the termination mechanisms in bacteria?

A)a (alpha)
B)b (beta)
C)r (rho)
D)d (delta)

Question 11

Which of the following terms defines nucleotide sequences that identify the location of transcription start sites and regulate the level of transcription?

A)sigma factors
B)Pribnow boxes
C)TATA boxes
D)promoters

Question 12

Which of the following base locations in DNA specifies the first base in the RNA transcript designated,and what numerical value is it assigned?

A)promoter;-5
B)enhancer;-35
C)transcription start site;0
D)transcription start site;+1

Question 13

Which of the following is a characteristic of rho (r)factor?

A)It winds transcript and template to free nascent RNA.
B)It recognizes and binds U-rich regions of RNA transcripts.
C)Its binding regions must be ribosome free.
D)It advances in the 3'à5' direction to the transcription bubble.

Question 14

Which of the following is where are nucleotides said to lie relative to the transcription site when they are in the "minus" direction?

A)downstream
B)upstream
C)downstrand
D)upstrand

Question 15

Which of the following is NOT a characteristic of the prokaryotic promoter for the rrn gene in E.coli?

A)It encodes for rRNA.
B)It has a -10 region Pribnow box.
C)It lacks a -35 region consensus sequence.
D)It has an upstream (UP)element at -55.

Question 16

Treatment of the RNA polymerase/DNA complex with DNase in vitro is a DNA footprinting technique.Which of the following is the technique used for?

A)to identify the termination sequence for transcription
B)to locate the start site for transcription
C)to locate the promoter site
D)to identify the position of enhancer sequences

Question 17

Which of the following is thought to be generated by transcription chain elongation?

A)positive supercoils behind the transcription bubble
B)positive supercoils in front of the transcription bubble
C)negative supercoils in front of the transcription bubble
D)a relaxed DNA during the transcription process

Question 18

The stand of dsDNA that is read by RNA polymerase is termed the template strand with RNA polymerase moving 3'?5' along it.Which of the following does the polymerase form,and in which direction does it grow?

A)transcript;3'?5'
B)transcript;5'?3'
C)template;3'?5'
D)template;5'?3'

Question 19

Which of the following processes is used by both prokaryotes and differentiated eukaryotic cells when they express a small number of their genes at any given time?

A)transcription
B)translation
C)replication
D)repair

Question 20

The initiation site binds a purine nucleotide base pairing with the +1 base exposed within the open promoter complex.Which of the following is where the second base is added?

A)to the 5'-C of the first base
B)to the 3'-C of the first base
C)to the 5'-O of the first base
D)to the 3'-O of the first base

Question 21

Which of the following terms for gene expression is often responsive to small molecules that increase synthesis of enzymes for metabolism of a certain substrate?

A)autoregulation
B)co-induction
C)induction
D)repression

Question 22

Heat shock element (HSE)is a response element found in the promoter region of genes.How is transcription of the HSE activated?

A)in response to cold
B)in response to elevated temperature
C)in response to sunlight
D)in response to darkness

Question 23

Which of the following is a characteristic of enhancer sequences in eukaryotic cells?

A)Enhancer function is dependent on recognition by a specific transcription factor.
B)They occur only upstream of the gene.
C)They can only be in one orientation.
D)Specific transcription factor binding at an enhancer inhibits transcription by reducting RNA polymerase II activity.

Question 24

Which of the following is NOT a component of the metallothionein gene promoter?

A)TATA box
B)GC box
C)glucocorticoids response element (GRE)
D)heat shock element (HSE)

Question 25

Which of the following a-amanitin-resistant RNA polymerases carries out transcription in eukaryotic cells?

A)I only
B)II only
C)III only
D)I and III

Question 26

Which of the following is needed for an inducible operon to be transcribed?

A)presence of a small molecule co-inducer
B)absence of a small molecule co-inducer
C)presence of a protein inducer
D)absence of a protein inducer

Question 27

Which of the following eukaryotic transcription factors exhibits sequence specificity for the TATA box?

A)TFIIB
B)TFIIC
C)TFIID/TBP
D)TFIIH

Question 28

Which of the following is a characteristic of RNA polymerase II?

A)located in the nucleolus and transcribes the major ribosomal RNA genes
B)located in the nucleoplasm and transcribes the protein-encoding genes through mRNAs
C)transcribes RNA genes associated with tRNA processing
D)transcribes tRNA genes and protein transport genes

Question 29

Which of the following is a feature of transcription activation?

A)A nucleotide sequence binding site for a DNA-binding protein serves as an activator site if DNA-binding protein can interact with promoter-bound RNA polymerase.
B)It takes place when a transcriptional activator protein bound to DNA makes protein:RNA contacts with RNA polymerase.
C)The degree of transcriptional activation is inversely proportional to the strength of the protein:protein interaction.
D)If the DNA-bound transcriptional activator makes contact with 2 different components of RNA polymerase,the transcription is markedly reduced.

Question 30

Which of the following is a property of the lac operon?

A)Allolactose increases the effect of the repressor.
B)Lactose represses the lac operon.
C)It is negatively controlled via CAP.
D)It is negatively controlled via the lac repressor.

Question 31

Which of the following is NOT a component of the lac operon?

A)the structural genes for lacZ,lacY,and lacA
B)the operator and promoter sequences
C)a lacI gene
D)a separate operator for the lacI gene

Question 32

Which of the following may NOT be a constituent of RNA polymerase II promoters?

A)the core element where general transcription factors bind
B)the site where enhancers bind transcriptional activators
C)the site where silencers bind inducers
D)a TATA box indicating the transcription start site

Question 33

Which of the following is a characteristic of catabolic activator protein (CAP)?

A)ensures that the operons necessary for metabolism for alternate energy sources remain activated until the supply of glucose is exhausted
B)C-terminal end binds cAMP,and N-terminal end binds DNA
C)overrides the influence of any inducer that might be present
D)N-terminal end binds cAMP,and C-terminal end binds DNA

Question 34

Which of the following is NOT a control mechanism that regulates transcription in prokaryotes?

A)protein:fatty acid interactions
B)DNA:protein interactions
C)RNA:protein interactions
D)fatty acid:cholesterol interactions

Question 35

Which of the following a feature of TATA boxes?

A)They are found outside the core sequence of a gene regulatory sequence.
B)They are found downstream of the gene being transcribed.
C)They reside in the enhancer regions.
D)They represent an area of DNA more easily opened than other areas.

Question 36

Which of the following is a property of the lac repressor?

A)dimeric protein expressed constitutively
B)binding site for PKA
C)blocks elongation so initiation is aborted
D)binding site for mRNA

Question 37

Which of the following occurs when the cellular level of tryptophan decreases in E.coli?

A)Tryptophan-bound Trp repressor associates with trp operator.
B)Trp apo-repressor has lowered affinity for trp promoter,allowing RNA polymerase binding and transcription of the trp operon.
C)Tryptophan binds trp inducer to promote positive control of trp promoter.
D)Trp repressor has a greater affinity for trp operator.

Question 38

Which of the following terms defines DNA-binding proteins that recognize and accurately initiate transcription at specific eukaryotic promoter sequences?

A)enhancers
B)transcription factors
C)response elements
D)chromatin-trascription remodelling complexes

Question 39

Which of the following terms defines the expression of genes independently of regulation?

A)autoregulation
B)constitutive expression
C)transcription expression
D)repressible regulation

Question 40

Which of the following occurs when the heptapeptide repeat in the carboxy terminal domain in the RPB1 subunit of RNA polymerase II is phosphorylated?

A)conversion to an elongation complex
B)binding to DNA
C)formation of a holo-RNA polymerase II
D)initiation of transcription

Question 41

Which of the following is NOT a component of the basic rule of macromolecular recognition?

A)Protein recognizes nucleotide sequences by atomic contacts with bases and sugar-phosphate backbone,usually in the major groove.
B)Protein contacts involve H-bonds and salt bridges with electronegative oxygens of the phosphodiester linkages.
C)Proteins present a 3-dimensional shape or contour,structurally and chemically complementary to the surface of the DNA sequence.
D)Numerous hydrophobic interactions underlie recognition and binding.

Question 42

Which of the following enzymes acetylate the e-amino group of lysine in the histidine tails,and what are they involved with?

A)histone deacetylases;restoring chromatin to a repressed state
B)histone acetyltransferases (HATs);initial events in transcriptional activation
C)histone activases;formation of the de-repression complex
D)histone kinase;promoting the formation of closed complexes

Question 43

The base-pair edges in the major groove act as a recognition matrix.How are they identifiable?

A)through van der Waals interactions with specific proteins
B)through hydrophobic interactions with specific proteins
C)through H-bonding with specific proteins
D)through ionic binding interactions with specific proteins

Question 44

Which of the following is a feature of transcription in eukaryotic cells?

A)Mature transcripts undergo continuous processing.
B)Transcription and translation are spatially coupled.
C)mRNAs are polycistronic.
D)Transcription occurs in the nucleus.

Question 45

Which of the following is NOT classified as a spliceosome?

A)snRNP
B)RNA-annealing protein
C)ATP-dependent RNA-unwinding protein
D)enzyme catalyzing hydrolysis of phosphoester

Question 46

Which of the following terms defines the huge multi-subunit entities that mediate ATP-dependent conformational changes that peel 50 bp of DNA from the edge of nucleosome core particles,and create a "bulge" in the DNA:core nucleosomes association?

A)histone deacetylase complexes
B)DNA-bound transcriptional activators
C)chromatin-remodelling complexes
D)general transcriptional factors

Question 47

Which of the following processes is the initial event in the conversion of an hnRNA to the mature RNA?

A)formation of ribonucleoprotein particles (RNPs)
B)capping the 5'-end of the transcript with a guanylyl group by guanylyl transferase
C)addition of a poly(A)tail to the 3'-end of the transcript by poly(A)polymerase
D)transesterification reactions in lariat formation

Question 48

Which of the following is a characteristic of homeobox domains?

A)act as sequence-specific transcriptional factors
B)typically comprise about 90% of the protein mass
C)found in only a few eukaryotes
D)contain helix-b-strand-helix motifs

Question 49

Which of the following DNA-binding motifs common to many prokaryotic regulatory proteins is the lac repressor an example of?

A)a homeobox
B)a zinc finger
C)a basic region-leucine finger
D)a helix-turn-helix

Question 50

Which of the following recurring structural features is found in DNA-binding proteins?

A)a-helix
B)b-sheet
C)b-turn
D)b-barrel

Question 51

Which of the following is NOT involved in the transcription of a typical gene encoding a polypeptide in eukaryotes?

A)the splicing together of a number of exons in the DNA prior to transcription
B)synthesis by RNA polymerase II
C)transcription of DNA corresponding to both introns and exons
D)addition of the poly(A)+ tail

Question 52

Which of the following is NOT a characteristic of intron excision and exon ligation (splicing)?

A)It occurs exclusively in the endoplasmic reticulum.
B)It involves hnRNA in ribonucleoprotein particles.
C)hnRNA is capped and polyadenylated.
D)It relies on snRNPs.

Question 53

Which of the following interactions hold the leucine zipper together?

A)H-bonds
B)hydrophobic interactions
C)ionic interactions
D)metal ion binding
E)protein:DNA interactions

Question 54

Which of the following is a characteristic of protein isoforms?

A)They are related polypeptides.
B)They have identical structure and function.
C)They are the result of different transcripts of a single gene.
D)They are mirror images.

Question 55

Which of the following pairs defines the coding and non-coding regions,respectively,for most eukaryotic RNA?

A)introns,exons
B)exons,introns
C)spliceons,codons
D)codons,spliceons

Question 56

Which of the following is a characteristic of the Zn-finger motif?

A)It binds the minor groove of DNA.
B)There is a repeated motif in DNA-binding proteins.
C)Two Cys and 2 Met coordinate the Zn.
D)It interacts with about 2 nucleotides/Zn finger.

Question 57

Which of the following is the structural motif found in a number of transcriptional factors that is not a DNA-binding domain,but rather is associated with protein-protein interactions?

A)a leucine zipper
B)a zinc finger
C)a helix-turn-helix
D)an enhancer element

Question 58

Which of the following is NOT a part of the process that leads to the production of multiple transcripts from a single gene?

A)constitutive splicing
B)use of different promoters
C)selection of different polyadenylation sites
D)alternative splicing of the primary transcript