Deck 12: Gene Transcription and Rna Modification

Question 1

If a nucleotide in a eukaryotic mRNA coding sequence does not appear in the genomic DNA sequence the most likely modification to have occurred is

A) Alternative splicing
B) RNA editing
C) 5' capping
D) Polyadenylation
E) Trimming

Answer 1

B

Question 2

A gene that undergoes rho-dependent termination has a mutation in the rut site. How will this influence transcriptional activity?

A) Transcription will terminate normally as Rho termination relies on the rut site to enhance termination; it is not essential for termination
B) Transcription will stop immediately because RNA polymerase will sense there is a mutation
C) Transcription will continue until another termination sequence, either Rho dependent or independent is reached
D) There will be no transcription initiation

Answer 2

C

Question 3

Where does the process of transcription initiate?

A) Promoter
B) Terminator
C) Regulation sequences
D) Transcription factors

Answer 3

A

Question 4

A mutation in TFIIIE could result in

A) a failure of the RNA polymerase to bind to TFIIB
B) a failure of the RNA polymerase to maintain an closed complex
C) a failure of the RNA polymerase to maintain an open complex
D) no effect on transcription

Question 5

The consensus sequences are 5'TTGACA3' and 5'TATAAT3' at -35 and -10 respectively. Which of the following would be most easily recognized by σ factor?

A) 5'TTGAAA3'
B) 5'TAAATT3'
C) 5'TATATA3'
D) 5'TTCAGA3'

Question 6

The holozyme is formed when the core enzyme associates with

A) Start codons
B) b
C) b'
D) σ
E) a

Question 7

What region in eukaryotic genes usually contains the majority of regulatory elements such as GC and CAAT boxes?

A) 0 to 50
B) -50 to 0
C) -50 to -100
D) -100 to -150

Question 8

What RNAs do each eukaryotic RNA polymerase produce?

A) RNA pol I - mRNA RNA pol II - tRNA and 5s rRNA
RNA pol III - rRNA
B) RNA pol I - rRNA RNA pol II - tRNA and 5s rRNA
RNA pol III - mRNA
C) RNA pol I - mRNA RNA pol II - rRNA
RNA pol III - tRNA and 5s rRNA
D) RNA pol I - rRNA RNA pol II - mRNA
RNA pol III - tRNA and 5s rRNA

Question 9

Which RNA encodes the sequence of amino acids for a functional protein?

A) tRNA
B) snRNA
C) mRNA
D) rRNA
E) scRNA

Question 10

Prokaryotic genes are colinear with their proteins, but this is not true for most eukaryotic genes

A) True
B) False
C) It is unknown at this time

Question 11

What sequences are not considered to be regulatory elements?

A) Enhancers
B) Silencers
C) Core promoters
D) Cis-acting elements
E) General transcription factors

Question 12

What basal transcription factor is a helicase?

A) TFIID
B) TFIIH
C) TFIIF
D) TFIIB

Question 13

In eukaryotic organisms, the processing of the 45S rRNA into 5.8S, 18S, and 28S rRNA occurs where?

A) In the cytoplasm
B) In the nucleolus
C) In the endoplasmic reticulum
D) In the Golgi body
E) Throughout the cell

Question 14

Which region of DNA contains the coding information for a protein in a eukaryote?

A) Exons
B) Introns
C) Enhancers
D) Promoters

Question 15

What is the difference between the allosteric and torpedo models of eukaryotic transcriptional termination?

A) The allosteric model is that RNA pol II becomes destabilized after transcription of the poly A signal sequence while the torpedo model is that the polymerase is physically removed from the DNA
B) The torpedo model is that RNA pol II becomes destabilized after transcription of the poly A signal sequence while the allosteric model is that the polymerase is physically removed from the DNA
C) The allosteric model is that RNA pol II becomes destabilized after transcription of the stop codon sequence while the torpedo model is that the polymerase is physically removed from the DNA
D) The torpedo model is that RNA pol II becomes destabilized after transcription of the stop codon while the allosteric model is that the polymerase is physically removed from the DNA
E) The only difference between the two models is the proteins that are involved in removing the RNA pol II from the DNA

Question 16

Which molecules are not part of the closed promoter complex?

A) RNA polymerase
B) Transcription factors
C) Double helix DNA
D) Single-stranded DNA

Question 17

RNaseP is not a protein but a ribozyme

Question 18

The RNA transcript is complimentary to

A) Regulatory sequences
B) Termination sequences
C) The coding strand of DNA
D) The template strand of DNA

Question 19

What modification acts to stabilize eukaryotic mRNA?

A) Alternative splicing
B) RNA editing
C) RNA interference
D) Polyadenylation
E) Trimming

Question 20

What enables the splicing of group I and II introns?

A) Spliceosomes
B) Ribozymes
C) snRNA
D) Poly-A tail

Question 21

The formation of open complex usually forms in GC rich regions of DNA due to the decreased number of hydrogen bonds.

Question 22

What is the correct order of elements that comprise a functional protein encoding gene in a prokaryote?

A) Promoter, regulatory region, transcribed region, terminator
B) Regulatory region, promoter, transcribed region, terminator
C) Regulatory region, promoter, terminator, transcribed region
D) Promoter, transcribed region, regulatory region, terminator

Question 23

The Prinbow box contains a CACAAC consensus sequence located in the -100 region of the promoter.

Question 24

What do both the rho-dependent and rho-independent mechanisms of termination have in common?

A) Terminate transcription immediately after the stop codon
B) A sequence rich with A-U base pairs
C) Both require a helicase to separate the DNA-RNA complex
D) Formation of a stem-loop structure

Question 25

The term ribozyme is given to catalytic RNA molecules.

Question 26

A main function of TFIID is

A) to recognize the TATA box
B) to act as a helicase
C) to terminate RNA polymerase II binding
D) to phosphorylate the CTD of RNA polymerase II

Question 27

In eukaryotes, enhancers must be close to the promoter to have an effect

Question 28

What structural motif is most commonly used by transcription factors in binding to DNA?

A) Zinc-finger
B) Helix-turn-helix
C) Leucine zipper
D) Homeodomain

Question 29

In the process of RNA editing adenine or cytosine may be deaminated and the result is

A) Adenine is changed to inosine and cytosine is changed to thymidine
B) Although both bases are covalently changed there is no alteration in the tRNAs the modified bases may engage
C) The new bases effectively result in new codons
D) Answers A and C are correct (B is incorrect)
E) Answers A and B are correct (C is incorrect)

Question 30

The process of RNA editing can alter the base sequence of the mRNA following transcription.

Question 31

What is the purpose of phosphorylating the carboxy terminal domain (CTD)?

A) Convert from initiation to the elongation stage
B) To aid in transcriptional initiation
C) Phosphorylate transcription factors
D) To aid in promoter recognition

Question 32

What occurs In both prokaryotic and eukaryotic tRNA maturation?

A) The pre tRNA molecule is trimmed by exo and endonucleases
B) The pre tRNA is spliced
C) The mature tRNA is capped at the 5' end
D) There is extensive RNA editing

Question 33

What is a mechanism by which tRNA is processed in E. coli?

A) RNaseP acts as an endonuclease
B) The recognition sequence of RNaseD is 3'CCA5'
C) RNAseD acts as an endonuclease
D) tRNA is not processed in E. coli

Question 34

During the initiation phase of transcription the sigma (σ) factor, which is bound to RNA polymerase, binds into the major groove of DNA and recognizes sequence elements at the promoter. This process forms a closed complex

Question 35

In bacterial RNA polymerase, the catalytic subunits are Beta and Beta'

Question 36

In prokaryotes elongation requires the release of the sigma factor, while in eukaryotes the Mediator is involved.

Question 37

What is unusual about the 5' cap found on almost all eukaryotic mRNAs?

A) The nucleotide added is a guanine methylated at N7 and the bond is created between the phosphate group on the guanine and the phosphate on the terminal nucleotide
B) The nucleotide added is a guanine methylated at N7 and the bond is a typical phosphodiester bond with the terminal nucleotide
C) The nucleotide added is an adenine methylated at N7 and the bond is created between the phosphate group on the guanine and the phosphate on the terminal nucleotide
D) The nucleotide added is an adenine methylated at N7 and the bond is typical phosphodiester bond with the terminal nucleotide

Question 38

What snRNP holds the exons in place so that they can be connected after the intron is removed?

A) U1
B) U2
C) U5
D) U6

Question 39

What percentage of human pre-mRNA is alternatively spliced

A) 70 %
B) 23%
C) 5%
D) 2%

Question 40

The RNA polymerase forms a closed complex during the process of elongation during transcription.

Question 41

Because of alternative splicing, a pre-mRNA could generate a dozen different mRNAs