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Cell Bio Exam 3 Dimario, chapter
8 Exam with Answers Graded A+
What kind of RNA does RNA polymerase I transcribe? RNA polymerase II and
III? Ans: - RNA polymerase I transcribed rRNAs
- RNA polymerase II transcribes mRNAs
- RNA polymerase III transcribes tRNAs
Differential sensitivities to what toxin allows you to determine which
polymerase transcribes a certain gene? Ans: Alpha aminitin
- RNA Pol I has low sensitivity
- RNA Pol II has very high sensitivity
- RNA Pol III intermediate
Which domain is associated with RNA Pol II and what is significant about it?
Ans: The Carboxyl terminal domain (CTD) in Pol II
- The Tyr and Ser residues of CTD will be phosphorylated during transcription
elongation (may be the trigger to begin transcription)
What is the transcription control region (element) that positions the initial
start site of transcription at +1? Ans: The TATA Box (within the promoter)
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- if sequences are deleted between TATA and true +1, initiation will still be 18-
26 bases down-stream of TATA
What elements could Pol II genes contain other than TATA elements? (2) Ans:
Just initiator elements
CpG-rich promoters for genes encoding enzymes for intermediary metabolism
("house-keeping genes")
- No TATA or initiator elements
- (5-methyl C) --> CpG rich promoters where C's can be methylated
What is significant about the direction that an RNA sequence can be
transcribed in regard to a CpG-rich promoter? Ans: CpG-rich promoters have
bi-directional initiation (they can go in each direction starting at the TSS-
Transcription Start Site.)
What technique is used to identify DNA sequences associated with defined
chromatin proteins and how does it work? (in the case we looked at, it was
RNA Pol II) Ans: Chromatin Immuno-Precipitations (ChIPs): It localizes
chromatin protein of interest within the genome.
- First step is to treat living cells or tissues with formaledehyde (a membrane
permeable cross-linker to cross-link proteins with DNA)
Cell Bio Exam 3 Dimario, chapter
8 Exam with Answers Graded A+
What kind of RNA does RNA polymerase I transcribe? RNA polymerase II and
III? Ans: - RNA polymerase I transcribed rRNAs
- RNA polymerase II transcribes mRNAs
- RNA polymerase III transcribes tRNAs
Differential sensitivities to what toxin allows you to determine which
polymerase transcribes a certain gene? Ans: Alpha aminitin
- RNA Pol I has low sensitivity
- RNA Pol II has very high sensitivity
- RNA Pol III intermediate
Which domain is associated with RNA Pol II and what is significant about it?
Ans: The Carboxyl terminal domain (CTD) in Pol II
- The Tyr and Ser residues of CTD will be phosphorylated during transcription
elongation (may be the trigger to begin transcription)
What is the transcription control region (element) that positions the initial
start site of transcription at +1? Ans: The TATA Box (within the promoter)
, 2|Page
- if sequences are deleted between TATA and true +1, initiation will still be 18-
26 bases down-stream of TATA
What elements could Pol II genes contain other than TATA elements? (2) Ans:
Just initiator elements
CpG-rich promoters for genes encoding enzymes for intermediary metabolism
("house-keeping genes")
- No TATA or initiator elements
- (5-methyl C) --> CpG rich promoters where C's can be methylated
What is significant about the direction that an RNA sequence can be
transcribed in regard to a CpG-rich promoter? Ans: CpG-rich promoters have
bi-directional initiation (they can go in each direction starting at the TSS-
Transcription Start Site.)
What technique is used to identify DNA sequences associated with defined
chromatin proteins and how does it work? (in the case we looked at, it was
RNA Pol II) Ans: Chromatin Immuno-Precipitations (ChIPs): It localizes
chromatin protein of interest within the genome.
- First step is to treat living cells or tissues with formaledehyde (a membrane
permeable cross-linker to cross-link proteins with DNA)
