Lecture 7: DNA Transcription Flashcards
Which of the following correctly describes a difference between DNA and RNA?
a) RNA contains thymine instead of uracil.
b) RNA has deoxyribose sugar, while DNA has ribose sugar.
c) RNA has uracil instead of thymine, and DNA has deoxyribose instead of ribose.
d) DNA contains a hydroxyl group at the 2’ position, while RNA has a hydrogen.
Answer: c) RNA has uracil instead of thymine, and DNA has deoxyribose instead of ribose.
During transcription in bacteria, the sigma factor:
a) Synthesizes RNA from DNA.
b) Provides energy for phosphodiester bond formation.
c) Helps RNA polymerase recognize the promoter sequence.
d) Cleaves the DNA strands.
Answer: c) Helps RNA polymerase recognize the promoter sequence.
Arrange the RNA types by their abundance in a cell (from most to least):
a) tRNA, rRNA, mRNA
b) rRNA, tRNA, mRNA
c) mRNA, rRNA, tRNA
d) rRNA, mRNA, tRNA
Answer: b) rRNA, tRNA, mRNA
Which of the following is FALSE about bacterial transcription?
a) Initiation of transcription occurs at the ATG start codon.
b) Promoters are regulatory DNA sequences found upstream of genes.
c) Different sigma factors allow transcription of different genes.
d) Efficiency of RNA synthesis increases in the elongation phase compared to initiation.
Answer: a) Initiation of transcription occurs at the ATG start codon.
What is the primary function of the TATA-binding protein (TBP) in transcription initiation?
a) To unwind the DNA double helix.
b) To phosphorylate RNA polymerase II.
c) To recognize and bind the TATA box in the promoter region.
d) To synthesize RNA from a DNA template.
Answer: c) To recognize and bind the TATA box in the promoter region.
Problem: Given the DNA template strand:
5’…GCATCACTTC…3’
What is the sequence of the transcribed RNA?
Answer: RNA sequence: 5’…CGUAGUGGAAG…3’
Problem: If the promoter sequence is located on the bottom strand of a DNA segment, and transcription proceeds in the 5’ to 3’ direction, which strand is used as the template?
Answer: The top strand will be the template strand.
Problem: You are designing an experiment to test RNA synthesis using reverse transcriptase. Which type of RNA would you convert to cDNA for sequencing the spike protein?
Answer: mRNA.
Problem: If a protein synthesis starts at the N-terminus, which direction does the ribosome move along the mRNA?
Answer: 5’ to 3’.
Problem: Describe how the termination of transcription is signaled in bacterial cells.
Answer: The RNA forms a hairpin loop structure by folding back on itself due to complementary base pairing, which signals the RNA polymerase to stop transcription.
Which of the following is NOT part of the central dogma of molecular biology?
a) DNA replication
b) RNA transcription
c) Protein synthesis
d) RNA to DNA synthesis
Answer: d) RNA to DNA synthesis
What is the role of reverse transcriptase?
a) To convert DNA into RNA
b) To convert RNA into DNA
c) To sequence DNA for proteins
d) To store genetic information permanently
Answer: b) To convert RNA into DNA
Why is reverse transcriptase used in RT-PCR?
a) To amplify DNA directly from cells
b) To create cDNA from RNA for further analysis
c) To degrade RNA after protein synthesis
d) To enhance the stability of RNA molecules
Answer: b) To create cDNA from RNA for further analysis
Which statement best describes the function of DNA in cells?
a) DNA acts as transient storage for genetic information.
b) DNA permanently stores genetic information.
c) DNA is synthesized from RNA.
d) DNA is primarily used for catalytic functions.
Answer: b) DNA permanently stores genetic information.
RNA is referred to as “transient storage” because:
a) It is used for long-term storage of genetic information.
b) It temporarily holds genetic information needed for protein synthesis.
c) It is resistant to degradation compared to DNA.
d) It serves as a catalyst in DNA replication.
Answer: b) It temporarily holds genetic information needed for protein synthesis.
In protein synthesis, mRNA is:
a) Stored in the nucleus for long-term use.
b) Transported to ribosomes for translation into protein.
c) Converted directly into DNA.
d) Broken down immediately after transcription.
Answer: b) Transported to ribosomes for translation into protein.
Why is mRNA often degraded after protein synthesis?
a) To prevent the production of excess proteins.
b) Because it is a permanent storage molecule.
c) To ensure long-term genetic stability.
d) To convert back into DNA.
Answer: a) To prevent the production of excess proteins.
Which of the following applications uses reverse transcriptase?
a) DNA fingerprinting
b) Reverse transcription PCR (RT-PCR)
c) Genome editing with CRISPR
d) Protein synthesis in ribosomes
Answer: b) Reverse transcription PCR (RT-PCR)
During transcription, RNA is:
a) Complementary to the coding strand of DNA.
b) Complementary to the template strand of DNA.
c) Identical to the template strand, except “T” is replaced with “U.”
d) Identical to the coding strand, including “T.”
Answer: b) Complementary to the template strand of DNA.
What is a key structural difference between RNA and DNA?
a) RNA contains thymine, while DNA contains uracil.
b) DNA has ribose, while RNA has deoxyribose.
c) RNA contains ribose, which has a hydroxyl group at the 2’ position.
d) DNA is more reactive than RNA due to the hydroxyl group in its sugar.
Answer: c) RNA contains ribose, which has a hydroxyl group at the 2’ position.
Why is RNA more reactive and less stable than DNA?
a) RNA contains uracil instead of thymine.
b) RNA lacks the 3’ hydroxyl group needed for stability.
c) RNA has an extra hydroxyl group at the 2’ position of its sugar.
d) RNA is single-stranded, while DNA is double-stranded.
Answer: c) RNA has an extra hydroxyl group at the 2’ position of its sugar.
What is true about the RNA sequence relative to the coding strand of DNA?
a) RNA is complementary to the coding strand.
b) RNA has the same sequence as the coding strand, except “T” is replaced with “U.”
c) RNA has the same sequence as the coding strand, including “T.”
d) RNA is identical to the template strand of DNA.
Answer: b) RNA has the same sequence as the coding strand, except “T” is replaced with “U.”
What is required for forming phosphodiester bonds during RNA elongation?
a) The presence of uracil in the template strand.
b) The 2’ hydroxyl group in ribose.
c) The 3’ hydroxyl group in ribose.
d) The removal of thymine from the RNA sequence.
Answer: c) The 3’ hydroxyl group in ribose.
What is the primary function of mRNA?
a) Catalyzing peptide bond formation
b) Storing genetic information permanently
c) Coding for proteins
d) Splicing introns from pre-mRNA
Answer: c) Coding for proteins
What is the role of ribosomal RNA (rRNA) in cells?
a) Coding for proteins
b) Catalyzing peptide bond formation and forming ribosome structure
c) Transporting amino acids to ribosomes
d) Regulating gene expression
Answer: b) Catalyzing peptide bond formation and forming ribosome structure
Transfer RNA (tRNA) plays what role in protein synthesis?
a) Synthesizing ribosomes
b) Translating mRNA codons into amino acids
c) Splicing pre-mRNA
d) Binding to ribosomal subunits
Answer: b) Translating mRNA codons into amino acids
Small nuclear RNAs (snRNAs) are involved in:
a) Protein synthesis
b) Splicing and modifying pre-mRNA
c) Transporting mRNA to the ribosome
d) Catalyzing tRNA binding
Answer: b) Splicing and modifying pre-mRNA
Small interfering RNAs (siRNAs):
a) Bind to ribosomes to catalyze protein synthesis
b) Regulate gene expression by degrading mRNA or establishing chromatin structures
c) Form ribosome subunits
d) Facilitate DNA replication
Answer: b) Regulate gene expression by degrading mRNA or establishing chromatin structures
What percentage of total RNA in a cell is ribosomal RNA (rRNA)?
a) 3–5%
b) 10–15%
c) 75–80%
d) Less than 5%
Answer: c) 75–80%
Which RNA type makes up less than 5% of total RNA in a cell?
a) tRNA
b) rRNA
c) mRNA
d) lncRNA
Answer: d) lncRNA
What is the primary function of piwi-interacting RNA (piRNA)?
a) Synthesizing ribosomal proteins
b) Regulating gene expression through mRNA degradation
c) Protecting germ line cells from transposable elements
d) Acting as adaptors between mRNA and amino acids
Answer: c) Protecting germ line cells from transposable elements
Telomerase RNA (TERC) functions as:
a) A catalyst for DNA replication at chromosome ends
b) A template for extending chromosome ends
c) A component of ribosomes
d) A regulator of mRNA degradation
Answer: b) A template for extending chromosome ends
Which RNA type is known for having structural and regulatory roles, but not for encoding proteins?
a) rRNA
b) tRNA
c) lncRNA
d) snRNA
Answer: c) lncRNA
The RNA transcribed from the template strand of DNA:
a) Is identical to the template strand except for “U” replacing “T.”
b) Is complementary to the template strand and has “U” instead of “T.”
c) Has the same sequence as the template strand, including “T.”
d) Has “U” instead of “T” but is identical to the coding strand.
Answer: b) Is complementary to the template strand and has “U” instead of “T.”
RNA is less stable than DNA because:
a) It contains uracil instead of thymine.
b) It has an extra hydroxyl group at the 2’ position of ribose.
c) It forms double-stranded helices.
d) It has a deoxyribose sugar.
Answer: b) It has an extra hydroxyl group at the 2’ position of ribose.
The most abundant RNA type in cells is:
a) mRNA
b) rRNA
c) tRNA
d) siRNA
Answer: b) rRNA
What is the primary role of RNA polymerase?
a) To synthesize DNA from RNA templates.
b) To synthesize RNA from DNA templates.
c) To replicate DNA.
d) To repair DNA strands.
Answer: b) To synthesize RNA from DNA templates.
Which statement best describes the primer requirement for RNA polymerase?
a) RNA polymerase requires an RNA primer to initiate synthesis.
b) RNA polymerase does not require a primer to initiate synthesis.
c) RNA polymerase requires a DNA primer for transcription.
d) RNA polymerase uses ribozymes as primers.
Answer: b) RNA polymerase does not require a primer to initiate synthesis.
Which polymerase has a more efficient proofreading mechanism?
a) RNA polymerase
b) DNA polymerase
c) Both have equal proofreading efficiency.
d) Neither has a proofreading mechanism.
Answer: b) DNA polymerase
RNA polymerase has an error rate of approximately:
a) 1 in 10⁴ rNTPs incorporated
b) 1 in 10⁷ rNTPs incorporated
c) 1 in 10⁹ rNTPs incorporated
d) No measurable error rate
Answer: a) 1 in 10⁴ rNTPs incorporated
RNA polymerase uses __________ as substrates to catalyze the formation of phosphodiester bonds.
a) Deoxyribonucleotides (dNTPs)
b) Ribonucleotides (rNTPs)
c) Both dNTPs and rNTPs
d) None of the above
Answer: b) Ribonucleotides (rNTPs)
DNA polymerase requires which of the following to initiate synthesis?
a) A pre-existing primer (either DNA or RNA)
b) A promoter region on the DNA template
c) A ribonucleotide sequence
d) No primer is required
Answer: a) A pre-existing primer (either DNA or RNA)
Both RNA polymerase and DNA polymerase synthesize nucleic acids in which direction?
a) 3’ to 5’
b) 5’ to 3’
c) Both directions simultaneously
d) Direction depends on the template strand orientation
Answer: b) 5’ to 3’
How does the error rate of DNA polymerase compare to that of RNA polymerase?
a) DNA polymerase has a higher error rate.
b) RNA polymerase has a higher error rate.
c) Both have the same error rate.
d) RNA polymerase has no error rate.
Answer: b) RNA polymerase has a higher error rate.
RNA polymerase and DNA polymerase both catalyze the formation of which type of
bond?
a) Hydrogen bonds between bases
b) Phosphodiester bonds between nucleotides
c) Peptide bonds between amino acids
d) Glycosidic bonds in sugars
Answer: b) Phosphodiester bonds between nucleotides
What is the primary role of DNA polymerase?
a) To repair RNA during transcription
b) To replicate DNA during cell division
c) To synthesize proteins from DNA templates
d) To degrade incorrect RNA sequences
Answer: b) To replicate DNA during cell division
What is the role of the sigma (σ) factor in RNA polymerase?
a) Synthesizing ribonucleotides.
b) Recognizing promoter sequences in DNA.
c) Unwinding double-stranded DNA.
d) Rewinding DNA after transcription.
Answer: b) Recognizing promoter sequences in DNA.
In E. coli, RNA polymerase is made up of:
a) Four subunits and two sigma factors.
b) Five subunits in the core enzyme and one sigma factor.
c) Five sigma factors and no core enzyme.
d) Six subunits, including the promoter.
Answer: b) Five subunits in the core enzyme and one sigma factor.
The promoter sequences recognized by RNA polymerase in prokaryotes include:
a) TATA box and -10 sequences.
b) -10 and -35 sequences.
c) TATAAT box and transcription start site.
d) -35 and -45 sequences.
Answer: b) -10 and -35 sequences.
During elongation, RNA polymerase performs all of the following EXCEPT:
a) Synthesizing RNA complementary to the DNA template.
b) Rewinding DNA behind it.
c) Releasing sigma factors.
d) Terminating transcription automatically.
Answer: d) Terminating transcription automatically.
The holoenzyme of RNA polymerase is:
a) The core enzyme without the sigma factor.
b) The core enzyme plus the sigma factor.
c) Only the sigma factor.
d) RNA polymerase without any subunits.
Answer: b) The core enzyme plus the sigma factor.
Which of the following statements about the sigma factor is NOT true?
a) It binds to promoter sequences to initiate transcription.
b) It remains attached throughout the transcription process.
c) It forms part of the RNA polymerase holoenzyme.
d) It dissociates once elongation begins.
Answer: b) It remains attached throughout the transcription process.
Which of the following is NOT true about promoters in E. coli?
a) They are recognized by sigma factors.
b) They include the -10 and -35 sequences.
c) They are transcribed into RNA.
d) They determine the transcription start site.
Answer: c) They are transcribed into RNA.
Which of the following is FALSE regarding RNA polymerase activity?
a) It synthesizes RNA in the 5’ to 3’ direction.
b) It catalyzes the formation of phosphodiester bonds.
c) It requires a primer to initiate synthesis.
d) It incorporates ribonucleotides complementary to the DNA template strand.
Answer: c) It requires a primer to initiate synthesis.
Which of the following is NOT true about prokaryotic RNA polymerase?
a) It has only one type of core enzyme.
b) Different sigma factors allow recognition of different promoters.
c) It can recognize promoters without the sigma factor.
d) It synthesizes RNA complementary to the template strand.
Answer: c) It can recognize promoters without the sigma factor.
Which of the following is FALSE about the RNA polymerase holoenzyme?
a) It requires sigma factors to identify promoter sequences.
b) It synthesizes RNA complementary to the coding strand.
c) It unwinds DNA at the transcription start site.
d) It releases the sigma factor after initiation.
Answer: b) It synthesizes RNA complementary to the coding strand.
During the initiation phase of transcription, which event occurs first?
a) Formation of the transcription bubble
b) Sigma factor binds the promoter
c) RNA polymerase synthesizes short abortive transcripts
d) Core enzyme binds sigma factor to form the holoenzyme
Answer: d) Core enzyme binds sigma factor to form the holoenzyme
What happens when the RNA polymerase holoenzyme binds the promoter?
a) Transcription bubble forms
b) A closed complex forms where DNA is still double-stranded
c) Sigma factor is released
d) RNA polymerase begins elongation
Answer: b) A closed complex forms where DNA is still double-stranded
Which of the following is NOT true about the initiation phase of transcription?
a) The sigma factor guides RNA polymerase to the promoter.
b) The DNA double helix is unwound to form a transcription bubble.
c) RNA polymerase releases the core enzyme after initiation.
d) Abortive transcripts are synthesized before promoter clearance.
Answer: c) RNA polymerase releases the core enzyme after initiation.
What triggers promoter clearance in the initiation phase?
a) The formation of the transcription bubble
b) The release of the sigma factor
c) Scrunching of DNA causing tension
d) Binding of ribonucleotides
Answer: c) Scrunching of DNA causing tension
During elongation, what happens to the DNA behind RNA polymerase?
a) It remains single-stranded.
b) It is rewound into its double-helix form.
c) It is degraded by nucleases.
d) It forms a hairpin structure.
Answer: b) It is rewound into its double-helix form.
Which of the following is TRUE about the elongation phase?
a) Sigma factor is still attached to RNA polymerase.
b) RNA polymerase reads the coding strand to synthesize RNA.
c) RNA polymerase adds ribonucleotides complementary to the template strand.
d) The transcription bubble closes completely.
Answer: c) RNA polymerase adds ribonucleotides complementary to the template strand.
What signals the end of the elongation phase?
a) Rebinding of the sigma factor
b) The formation of a hairpin structure in the RNA
c) The addition of ribonucleotides
d) The rewinding of DNA behind RNA polymerase
Answer: b) The formation of a hairpin structure in the RNA
What happens to the RNA polymerase core enzyme after termination?
a) It dissociates from the DNA and RNA completely.
b) It reassociates with a sigma factor to begin a new transcription cycle.
c) It continues elongation without the sigma factor.
d) It binds to the RNA for translation.
Answer: b) It reassociates with a sigma factor to begin a new transcription cycle.
Which of the following is NOT part of the termination phase?
a) RNA forms a hairpin loop
b) RNA polymerase transcribes the termination sequence
c) DNA is left single-stranded
d) The RNA strand is released from RNA polymerase
Answer: c) DNA is left single-stranded
Arrange the steps of bacterial transcription in order:
i. Formation of the holoenzyme
ii. Sigma factor release
iii. Hairpin loop formation
iv. Open complex formation
a) i, iv, ii, iii
b) iv, i, iii, ii
c) i, ii, iv, iii
d) iv, iii, i, ii
Answer: a) i, iv, ii, iii
During the transcription cycle, when does the sigma factor dissociate?
a) After the formation of the holoenzyme
b) During the elongation phase
c) At the end of the initiation phase
d) After the termination phase
Answer: c) At the end of the initiation phase
What ensures the specificity of RNA polymerase for different genes in prokaryotes?
a) Different core enzymes
b) Different sigma factors
c) Different types of promoters
d) Different ribonucleotides
Answer: b) Different sigma factors
What does the 5’ untranslated region (UTR) refer to in a gene?
a) The coding region of the gene.
b) The region upstream of the translation start codon, not translated into protein.
c) The portion of RNA containing the promoter sequences.
d) The part of the gene transcribed but not part of the final RNA product.
Answer: b) The region upstream of the translation start codon, not translated into protein.
Why are the transcription start and stop sites located outside the translation start and stop codons?
a) To include UTRs necessary for RNA stability and translation regulation.
b) To prevent the gene from being transcribed into mRNA.
c) To directly code for ribosomal proteins.
d) To allow RNA polymerase to bind to ribosomes.
Answer: a) To include UTRs necessary for RNA stability and translation regulation.
What marks the boundaries of the coding region in a prokaryotic gene?
a) Promoter and terminator.
b) Transcription start and stop sites.
c) Translation start (AUG) and stop codons.
d) Upstream and downstream sequences.
Answer: c) Translation start (AUG) and stop codons.
In translation, the N-terminus of the protein corresponds to:
a) The 3’ end of the mRNA.
b) The 5’ end of the mRNA.
c) The transcription start site of the gene.
d) The carboxyl terminus of the polypeptide.
Answer: b) The 5’ end of the mRNA.
During translation, amino acids are added to:
a) The N-terminus of the growing polypeptide chain.
b) The C-terminus of the growing polypeptide chain.
c) Both ends simultaneously.
d) The ribosome itself.
Answer: b) The C-terminus of the growing polypeptide chain.
What is the purpose of the transcription bubble?
a) To separate ribosomes for translation.
b) To expose the DNA template strand for RNA synthesis.
c) To signal the termination phase of transcription.
d) To rewind DNA after transcription.
b)To expose the DNA template strand for RNA synthesis.
Which statement is TRUE about the elongation phase of transcription?
a) RNA polymerase synthesizes DNA complementary to the RNA template strand.
b) DNA ahead of RNA polymerase unwinds, while DNA behind rewinds.
c) Sigma factor remains bound to RNA polymerase throughout elongation.
d) The promoter sequence is transcribed into RNA.
Answer: b) DNA ahead of RNA polymerase unwinds, while DNA behind rewinds.
In prokaryotic transcription, termination occurs when:
a) The RNA polymerase reaches the promoter region.
b) The RNA transcript forms a hairpin loop.
c) The ribosome signals RNA polymerase to stop.
d) The sigma factor rebinds to the RNA polymerase.
Answer: b) The RNA transcript forms a hairpin loop.
Which of the following statements is FALSE about transcription in bacteria?
a) Initiation of transcription occurs at the ATG start codon.
b) Promoters are regulatory DNA sequences found upstream of genes.
c) Different sigma factors allow transcription of specific genes.
d) The elongation phase is more efficient than the initiation phase.
Answer: a) Initiation of transcription occurs at the ATG start codon.
Which of the following is NOT true about the 3’ untranslated region (3’ UTR)?
a) It is transcribed but not translated.
b) It contains signals for RNA stability and translation regulation.
c) It codes for the final amino acid of the polypeptide.
d) It is located downstream of the coding region.
Answer: c) It codes for the final amino acid of the polypeptide.
What is the primary determinant of which DNA strand is used as the template for transcription?
a) The presence of ribosomes on the DNA strand.
b) The asymmetry and orientation of the promoter sequence.
c) The direction of the coding sequence.
d) The 3’ end of the DNA strand.
Answer: b) The asymmetry and orientation of the promoter sequence.
If RNA polymerase moves from 5’ to 3’ on the RNA being synthesized, which direction is the template strand being read?
a) 3’ to 5’
b) 5’ to 3’
c) Both directions simultaneously
d) Template strand orientation does not matter
Answer: a) 3’ to 5’
The template strand of DNA is also known as:
a) The sense strand.
b) The coding strand.
c) The antisense strand.
d) The promoter strand.
Answer: c) The antisense strand.
How does the orientation of the promoter influence transcription?
a) It determines the length of the RNA transcript.
b) It dictates which strand of DNA is used as the template and the direction RNA polymerase moves.
c) It determines where the ribosome will bind.
d) It controls the 3’ end of the RNA transcript.
Answer: b) It dictates which strand of DNA is used as the template and the direction RNA polymerase moves.
If RNA polymerase binds to a promoter facing left to right (5’ to 3’ direction), which strand is the template strand?
a) The bottom strand
b) The top strand
c) Both strands simultaneously
d) Neither strand
Answer: a) The bottom strand
What allows genes within the same DNA molecule to be transcribed using different template strands?
a) Different orientations of the promoter sequence.
b) The placement of stop codons.
c) The simultaneous binding of RNA polymerase to both strands.
d) The length of the coding region.
Answer: a) Different orientations of the promoter sequence.
If Gene A uses the bottom strand as the template and Gene B uses the top strand, what explains this difference?
a) The two genes have different promoter sequences with specific orientations.
b) Gene B is not transcribed in the 5’ to 3’ direction.
c) RNA polymerase recognizes only the coding strand.
d) Gene A is longer than Gene B.
Answer: a) The two genes have different promoter sequences with specific orientations.
What is indicated by the “blunt” end and “pointy” end notation on DNA diagrams?
a) The 3’ end is the blunt end, and the 5’ end is the pointy end.
b) The 5’ end is the blunt end, and the 3’ end is the pointy end.
c) Both ends are blunt in double-stranded DNA.
d) The pointy end represents the end of transcription.
Answer: b) The 5’ end is the blunt end, and the 3’ end is the pointy end.
How many types of RNA polymerases are present in eukaryotes?
a) 1
b) 2
c) 3
d) 5
Answer: c) 3
Which RNA polymerase in eukaryotes is responsible for transcribing mRNA?
a) RNA Polymerase I
b) RNA Polymerase II
c) RNA Polymerase III
d) All of the above
Answer: b) RNA Polymerase II
In prokaryotes such as E. coli, how many RNA polymerases are there?
a) 1
b) 2
c) 3
d) 5
Answer: a) 1
Which type of RNA polymerase is insensitive to alpha-amanitin in eukaryotes?
a) RNA Polymerase I
b) RNA Polymerase II
c) RNA Polymerase III
d) None of the above
Answer: a) RNA Polymerase I
Which RNA polymerase transcribes tRNAs in eukaryotes?
a) RNA Polymerase I
b) RNA Polymerase II
c) RNA Polymerase III
d) All RNA polymerases
Answer: c) RNA Polymerase III
What is the function of the pre-initiation complex (PIC) in eukaryotic transcription?
a) To terminate transcription.
b) To guide RNA polymerase II to the promoter.
c) To transcribe mRNA directly from DNA.
d) To stabilize ribosomes for protein synthesis.
Answer: b) To guide RNA polymerase II to the promoter.
The TATA-binding protein (TBP) is a part of which component of the PIC?
a) TFIID
b) TFIIB
c) TFIIH
d) RNA Polymerase II
Answer: a) TFIID
What is the role of TFIIH in the pre-initiation complex?
a) Binding the TATA box.
b) Phosphorylating the C-terminal domain of RNA Polymerase II.
c) Synthesizing RNA.
d) Terminating transcription.
Answer: b) Phosphorylating the C-terminal domain of RNA Polymerase II.
Which of the following is NOT true about the pre-initiation complex?
a) It is essential for the initiation of transcription in eukaryotes.
b) It includes general transcription factors like TFIID, TFIIH, and TFIIB.
c) It unwinds the DNA at the promoter region.
d) It directly synthesizes RNA
.
Answer: d) It directly synthesizes RNA.
What is the purpose of the phosphorylation of RNA Polymerase II’s C-terminal domain (CTD) by TFIIH?
a) To unwind DNA at the promoter.
b) To transition RNA Polymerase II into elongation.
c) To bind ribosomes for translation.
d) To terminate transcription.
.
Answer: b) To transition RNA Polymerase II into elongation
Which general transcription factor includes helicase activity?
a) TFIID
b) TFIIB
c) TFIIH
d) TFIIE
Answer: c) TFIIH
In the transcription process of eukaryotes, what is the sequence of events involving the pre-initiation complex?
a) TBP binds TATA box → TFIID recruits other factors → RNA Polymerase II binds → TFIIH phosphorylates CTD
b) TFIID binds TATA box → RNA Polymerase II synthesizes RNA → TFIIH terminates transcription
c) TBP unwinds DNA → TFIIB releases the PIC → RNA Polymerase II binds to the ribosome
d) TFIIE transcribes the gene → RNA Polymerase II terminates transcription
Answer: a) TBP binds TATA box → TFIID recruits other factors → RNA Polymerase II binds → TFIIH phosphorylates CTD
Which of the following correctly describes the difference between prokaryotes and eukaryotes in terms of transcription factor requirements?
a) Prokaryotes require auxiliary transcription factors, while eukaryotes do not.
b) Eukaryotes require auxiliary transcription factors for RNA polymerase II to bind the promoter, while prokaryotes rely on sigma factors.
c) Both prokaryotes and eukaryotes rely exclusively on sigma factors for RNA polymerase binding.
d) Prokaryotes and eukaryotes both require the TATA-binding protein (TBP) for transcription initiation.
Answer:
b) Eukaryotes require auxiliary transcription factors for RNA polymerase II to bind the promoter, while prokaryotes rely on sigma factors.
