Transcription, Translation, and Bioinformatics Chapter 8 Review Questions with Verified Answers Latest Update (Graded A+)

Transcription, Translation, and Bioinformatics Chapter 8 Review Questions with Verified Answers Latest Update (Graded A+) ____________ RNA polymerase plus sigma factor together are called _______________. a) transcription; translation b) holoenzyme; core c) translation; transcription d) core; holoenzyme e) ribosome; rRNA - Answers d) core; holoenzyme Without ____________, the core RNA polymerase binds and releases DNA at random. a) initiation factor b) Shine-Dalgarno sequence c) sigma factor d) peptidyltransferase e) release factor - Answers c) sigma factor The RpoH sigma-70 factor of E. coli recognizes promoters for: a) stress response genes b) motility and chemotaxis genes c) 'housekeeping' genes d) heat shock-induced genes e) genes for nitrogen metabolism - Answers c) 'housekeeping' genes Which of the following is NOT part of initiation of transcription? a) -10 and -35 sequences b) binding of RNA polymerase to the beginning of the gene c) melting of the helix d) binding of sigma factor to promoter followed by binding of core RNA polymerase e) base pairing of the first nucleotide of the RNA - Answers d) binding of sigma factor to promoter followed by binding of core RNA polymerase An enzyme complex called RNA polymerase is also known as DNA-dependent RNA polymerase because: a) DNA codes for the subunits of the protein b) DNA serves as a template for translation c) hydrolysis of DNA provides the energy for RNA polymerase d) DNA serves as a template for transcription e) DNA is required as a primer for this polymerase - Answers d) DNA serves as a template for transcription A consensus sequence consists of: a) region to which sigma factors can bind b) most likely base (or bases) at each position c) hairpins in RNA to slow down or stop transcription d) sequences to which ribosomes bind e) primer sequences used to initiate transcription - Answers b) most likely base (or bases) at each position Molecules of sRNA do not encode proteins, but are used to ___________ the translation of specific mRNAs into proteins. a) start b) regulate c) stop d) speed up e) slow down - Answers b) regulate The average half-life for mRNA in a typical bacterium such as E. coli is: a) 1-3 sec b) 10-30 sec c) 1-3 min d) 1-3 hours e) 1-3 days - Answers c) 1-3 min Which of the following is NOT true of initiation of transcription? a) the RNA polymerase holoenzyme binds b) GTP hydrolysis catalyzes bubble formation c) promoter unwinds d) first rNTP is usually a purine e) position +1 marks the start of the gene - Answers b) GTP hydrolysis catalyzes bubble formation In the absence of Rho, what can bring about transcription termination? a) stem and loop and stretches of uracil residues b) stem and loop only c) GC-rich region d) GC-rich region followed by uracil residues e) stem and loop followed by a GC-rich region - Answers d) GC-rich region followed by uracil residues