Microbiology Evolving Science 3rd Edition by Slonczewski Foster – Test Bank

Microbiology Evolving Science 3rd Edition by Slonczewski Foster – Test Bank

CHAPTER 8: Transcription, Translation, and Bioinformatics

MULTIPLE CHOICE

1. __________ RNA polymerase plus sigma factor together are called __________.
a. Transcription; translation d. Core; holoenzyme
b. Holoenzyme; core e. Ribosome; rRNA
c. Translation; transcription

ANS: D DIF: Easy REF: 8.1 TOP: I.A.i
MSC: Remembering

2. Without __________, the core RNA polymerase binds and releases DNA at random.
a. initiation factor d. peptidyltransferase
b. Shine-Dalgarno sequence e. release factor
c. sigma factor

ANS: C DIF: Medium REF: 8.1 TOP: I.A.ii
MSC: Remembering

3. The RpoH sigma-70 factor of E. coli recognizes promoters for:
a. stress response genes d. heat shock–induced genes
b. motility and chemotaxis genes e. genes for nitrogen metabolism
c. “housekeeping” genes

ANS: C DIF: Medium REF: 8.1 TOP: I.A.iii
MSC: Remembering

4. 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

ANS: D DIF: Medium REF: 8.1 TOP: I.A
MSC: Understanding

5. An enzyme complex called RNA polymerase is also known as DNA-dependent RNA polymerase because:
a. DNA codes for the subunits of this 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

ANS: D DIF: Medium REF: 8.1 TOP: I.A
MSC: Applying

6. A consensus sequence consists of:
a. the region to which sigma factors can bind
b. the 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

ANS: B DIF: Easy REF: 8.1 TOP: I.A.iii.a
MSC: Applying

7. Molecules of sRNA do not encode proteins, but are used to __________ the translation of specific mRNAs into proteins.
a. start d. speed up
b. regulate e. slow down
c. stop

ANS: B DIF: Medium REF: 8.2 TOP: II.D.iv
MSC: Remembering

8. The average half-life for mRNA in a typical bacterium such as E. coli is:
a. 1–3 seconds d. 1–3 hours
b. 10–30 seconds e. 1–3 days
c. 1–3 minutes

ANS: C DIF: Medium REF: 8.2 TOP: II.E
MSC: Remembering

9. Which of the following is NOT true of initiation of transcription?
a. The RNA polymerase holoenzyme binds.
b. GTP hydrolysis catalyzes bubble formation.
c. The promoter unwinds.
d. The first rNTP is usually a purine.
e. Position +1 marks the start of the gene.

ANS: B DIF: Difficult REF: 8.2 TOP: II.A.i
MSC: Understanding

10. In the absence of rho, what can bring about transcription termination?
a. stem and loop and stretches of uridines
b. stem and loop only
c. GC-rich region
d. GC-rich region followed by four to eight uridines
e. stem and loop followed by a GC-rich region

ANS: D DIF: Medium REF: 8.2 TOP: II.A.iii
MSC: Understanding