RNA synthesis and processing Flashcards
- Transcription is _______-dependent _______ synthesis.
a. DNA; DNA
b. DNA; RNA
c. RNA; DNA
d. RNA; protein
b. DNA; RNA
2. The prokaryotic cells most commonly used to study transcription and translation are from a. E. coli. b. B. subtilis. c. S. cerevisiae. d. D. discoidium
a. E. Coli
- RNA polymerase differs from DNA polymerase in that it
a. synthesizes new strands of RNA in a 3′ to 5′ direction.
b. is a monomeric protein.
c. can synthesize a complementary strand without the two strands of DNA being
separated.
d. does not require a primer to initiate synthesis of RNA.
d. does not require a primer to initiate synthesis of RNA.
4. The DNA sequence to which an RNA polymerase binds to initiate transcription of a gene is called a(n) a. enhancer. b. promoter. c. polymerase-binding element. d. origin of transcription.
b. promoter
- The regions of the DNA where RNA polymerase binds can be identified by
a. restriction mapping.
b. PCR.
c. DNA footprinting.
d. polymerase mapping.
c. DNA footprinting.
- The role of the sigma (σ) factor in prokaryote transcription is to
a. unwind the DNA during transcription.
b. provide specificity to binding to the promoter region.
c. recognize the transcription initiation site.
d. terminate transcription.
c. recognize the transcription initiation site.
- Transcription of a bacterial gene is initiated
a. with RNA polymerase in the closed promoter complex.
b. after release of the sigma (σ) factor
c. with RNA polymerase in the open promoter complex.
d. Both a and b
c. with RNA polymerase in the open promoter complex
- Termination of transcription in E. coli occurs by
a. formation of a stem-loop structure in the RNA.
b. binding of Rho protein to the end of the mRNA.
c. binding of a sigma (σ) factor to the end of the mRNA.
d. Either a or b
d. Either a or b
- The pioneering studies of gene regulation in E. coli were done in the 1950s by
a. Miller and Urey.
b. Watson and Crick.
c. Jacob and Monod.
d. Lerner and Lowe.
c. Jacob and Monod.
10. One would expect the mRNA produced from the lac operon of E. coli to hybridize to the a. lac i+ gene. b. lac o region. c. β-galactosidase gene. d. All of the above
b. lac o region.
11. The lac operon in E. coli is regulated by lactose, which \_\_\_\_\_\_\_ a(n) \_\_\_\_\_\_\_ of transcription. a. activates; activator b. inactivates; activator c. activates; repressor d. inactivates; repressor
d. inactivates; repressor
- The lac operator consists of approximately 20 base pairs of DNA located
a. 80–100 base pairs upstream of the transcription initiation site.
b. 20–40 base pairs upstream of the transcription initiation site.
c. in a position overlapping the initiation site.
d. downstream of the transcription initiation site.
b. 20–40 base pairs upstream of the transcription initiation site.
- When the operator gene has an operator constitutive mutation (oc), the gene(s) regulated by it are
a. off when they should be on.
b. always off.
c. always on.
d. regulated by the presence of the repressor.
c. always on.
- Catabolite repression in E. coli
a. inhibits the breakdown of glucose in the presence of lactose.
b. is reversed by cAMP binding to catabolite activator protein.
c. inhibits the lac operon unless lactose is present.
d. is a negative feedback system.
b. is reversed by cAMP binding to catabolite activator protein.
- The first step in forming a transcription complex for mRNA transcription is binding
of which of the following to the TATA box?
a. TFIA
b. TFIIA
c. TFIIIA
d. TFIID
d. TFIID
- Release of RNA polymerase II to initiate transcription appears to be the direct result
of
a. binding of TAFs to the polymerase.
b. unwinding of the DNA by helicases.
c. phosphorylation of RNA polymerase by a protein kinase.
d. removal of the nucleosome occupying the promoter site.
c. phosphorylation of RNA polymerase by a protein kinase.
- A reporter gene is one that
a. causes other genes to be expressed.
b. can produce a product that is easily detected when expressed under the control of a
regulatory sequence to which it has been ligated and cloned.
c. is always on.
d. is turned on by the products of other genes.
b. can produce a product that is easily detected when expressed under the control of a
regulatory sequence to which it has been ligated and cloned.
- A major difference between eukaryotic and prokaryotic RNA polymerases is that
eukaryotic polymerases
a. use a set of transcription factors to bind to and initiate transcription.
b. use sigma (σ) factors to initiate transcription.
c. start from promoters.
d. start from origins of replication.
a. use a set of transcription factors to bind to and initiate transcription.