Genetics Exam 3- UC Practice Questions And Well Elaborated Answers.

What is the most important difference between DNA polymerases and RNA polymerases? (NOT "DNA vs RNA") - correct answers DNA requires a primer while RNA does not RNA polymerases can begin transcription anywhere. How does the cell determine where transcription should start? - correct answers Wherever the promoter region is where transcription starts In prokaryotes, the site of transcription initiation is determined by A. the position of an RNA primer. B. the position of a DNA primer. C. binding of TATA-Binding Protein to a TATA box. D. binding of RNA Polymerase + Sigma factor to the -10 and -35 consensus sequences. - correct answers D. binding of RNA Polymerase + Sigma factor to the -10 and -35 consensus sequences. In Eukaryotes, the site of transcription initiation is determined by : A. the position of an RNA primer. B. the position of a DNA primer. C. binding of TATA-Binding Protein to a TATA box. D. binding of RNA Polymerase + Sigma factor to the -10 and -35 consensus sequences - correct answers C. Binding of TATA-Binding Protein to a TATA box In Prokaryotes, transcription starts: A. at the TATA box. B. 10 bases "downstream" of the -10 site. C. at the -35 site. D. at the -10 site - correct answers B. 10 bases "downstream" of the -10 site Prokaryote promoter: - correct answers Tells RNA polymerase where to bind and specifies START SITE, Direction of Transcription, Template Strand In transcription, do you need AUG to start? - correct answers No, that is only for translation In prokaryotes, the start of transcription is determined by A. A specific start DNA sequence; the holoenzyme binds to whatever DNA is 10 and 35 bases "upstream" from the transcription start site. B. Where the holoenzyme is bound to DNA; the holoenzyme only binds to the specific consensus sequences we call -10 and -35 sites - correct answers B. Where the holoenzyme is bound to DNA What does the TATA box do? - correct answers Initiates transcription by being a binding site for transcription factors In a eukaryotic Pol-II promoter, the TATA box is important because A. It unwinds the double helix to allow one strand to be transcribed. B. It is the DNA sequence that is recognized and bound by the TATA-binding protein. C. It is always single-stranded and therefore accessible to TATA-binding protein. D. It is a short RNA that acts as a primer for transcription - correct answers B. It is the DNA sequence that is recognized and bound by the TATA-binding protein What binds to the core promoter? - correct answers GTFs to help position RNA polymerase 2 What binds to the regulatory promoter? - correct answers STFs like enhancers and repressors What do enhancers, regulatory promoter and core promoters have in common? - correct answers All contain specific DNA sequences that serve as binding sites A transcription bubble is A. a region of dissociated DNA duplex maintained by RNA polymerase in both prokaryotes and eukaryotes. B. a sub-compartment within the nucleus where transcription occurs in eukaryotes. C. a region in prokaryotes where multiple mRNA transcripts can be seen in an electron micrograph. D. the region either side of the TATA box where the template DNA is bent at nearly a right angle. - correct answers A. A region of dissociated DNA duplex maintained by RNA polymerase in both karyotes The energy used by RNA Polymerase to attach the nextribonucleotide to the growing mRNA comes from A. Hydrolysis of the pyrophosphate released from the incoming ribonucleotide triphosphate. B. ATP. C. Hydrolysis of the preceding sugar-phosphate bond. D. Sigma factor. - correct answers A. Hydrolysis of Phosphate and B. ATP Why is the non-template strand called the coding strand? - correct answers It is identical to the RNA transcript In Prokaryotes, the 3' end of an mRNA is determined by A. a specific sequence, but not the stop codon. B. the stop codon. C. post-transcriptional modification of the mRNA. D. incorporation of a variant ribonucleotide. - correct answers A. A specific sequence, but not the stop codon In Rho-dependent termination, Rho is a(n) A. mRNA secondary structure. B. DNA sequence that causes RNA Polymerase to stall. C. protein that initially binds to the Rut site in the gene. D. protein that initially binds to the Rut site on the growing mRNA - correct answers D. protein that initially binds to the RUT site on the growing mRNA What kind of structure does the terminator sequence form? - correct answers A secondary structure In eukaryotes, most mRNA transcription. A. is terminated by the "Rho" protein. B. terminates when RNA Polymerase encounters a Stop codon. C. continues until the RNA Polymerase encounters polyadenylation. D. does not have a specific endpoint - correct answers D. Does not have a specific endpoint Transcription and translation occur simultaneously for a single mRNA in A. Prokaryotes. B. Eukaryotes. C. Both