BIO 112 Chapter 17

In eukaryotes, there are several different types of RNA polymerases. Which type is involved in transcription of mRNA for a globin protein?

• RNA polymerase I

• RNA polymerase II

• RNA polymerase III

• RNA polymerase IV

• Primase

Which molecule or reaction supplies the energy for polymerization of nucleotides in the process of transcription?

• The interaction between RNA polymerase and the promoter

• The phosphate bonds in the nucleotide triphosphates that serve as substrates

• The energy released when hydrogen bonds are broken as the DNA molecule is unwound

• ATP only

Death cap mushrooms produce a substance called alpha-amanitin. Alpha-amanitin efficiently blocks synthesis of mRNA, but not of tRNA or rRNA, in eukaryotic organisms. This is possible because alpha-amanitin efficiently interferes with _______.

• the action of RNA polymerase I, but not RNA polymerase II or III

• RNA polymerase III, but not RNA polymerase I and II

• the action of RNA polymerases I and II, but not RNA polymerase III

• the action of RNA polymerase II, but not RNA polymerase I or III

You want to engineer a eukaryotic gene into a bacterial colony so the bacteria express the gene. What must be included in addition to the coding exons of the gene?

• The introns

• Eukaryotic polymerases

• A bacterial promoter sequence

• Eukaryotic ribosomal subunits

• Eukaryotic tRNAs

In eukaryotic cells, transcription cannot begin until _______.

• A) the two DNA strands have completely separated and exposed the promoter

• B) several transcription factors have bound to the promoter

• C) the 5' caps are removed from the mRNA

• D) the DNA introns are removed from the template

• E) DNA nucleases have isolated the transcription unit

The enzyme complex associated with DNA in the associated figure is __________.

• helicase

• DNA polymerase

• RNA polymerase

• topoisomerase

In E. coli, if RNA polymerase is missing __________, then transcription initiation would not occur at the appropriate initiation sites.

• A) amino acids

• B) mRNA

• C) sigma

• D) the core enzyme

David Pribnow studied the base sequences of promoters in bacteria and bacterial viruses. He found two conserved regions in these promoters (the –10 box and the –35 box). These two regions of the promoter ________.

• A) signal the initiation site

• B) bind the sigma subunit that is associated with RNA polymerase

• C) attach the correct nucleotide triphosphate to the template DNA strand

• D) separate the two DNA strands

Which of the following processes is central to the initiation of transcription in bacteria?

• A) Binding of sigma to the promoter region

• B) Formation of a phosphodiester bond in the elongating RNA strand

• C) Binding of DNA polymerase to the promoter region

• D) Formation of a DNA primer

Termination of transcription in bacteria occurs when ________.

• A) a hairpin secondary structure forms in the RNA transcript, and it separates from the RNA polymerase

• B) a deoxyribonucleotide is base-paired to the 3' end of the transcript, signaling completion

• C) large and small subunits of the RNA polymerase dissociate

• D) the 5' cap structure on the nascent (new) RNA molecule loops back and interferes with RNA polymerase