Ch 10 Concept Questions (PPT) – Flashcards

Small interfering RNA (siRNA) molecules block gene expression by degrading mRNA or inhibiting transcription. Which genes do they target? a. genes from which they were transcribed b. genes other than those they were transcribed from. c. random genes in the genome. d. transposon genes.

When RNA is transcribed from a gene, which strand of DNA is used? a. the template strand b. the nontemplate strand c. RNA is transcribed from either strand at random. d. RNA is transcribed from either strand in a regulated manner.

The transcription unit includes three essential regions. What is the proper order of these regions? a. terminator, RNA coding sequence, promoter b. RNA coding sequence, promoter, terminator c. promoter, RNA coding sequence, terminator d. RNA coding sequence, terminator, promoter e. promoter, terminator, RNA coding sequence

Which of the following statements is NOT correct about the process of transcription? a. Transcription of a given gene takes place on only one of the two DNA strands. b. During transcription the RNA molecule is synthesized in the 3 to 5 direction. c. During transcription the RNA molecule that is synthesized is anti-parallel and complementary to the template DNA strand. d. The start site and direction of transcription are determined by a region of the nontemplate DNA strand known as the promoter. e. The RNA molecule that is synthesized will have U in place of T.

What would the result be if a specific sigma subunit of bacterial RNA polymerase were mutated? a. Nothing would result; sigma is not essential. b. RNA polymerase would still bind DNA at specific sites, but will fall off after joining together only a few RNA nucleotides. c. RNA polymerase would initiate transcription at random on the DNA. d. The core enzyme would not be as stable as usual.

The bacterial holoenzyme binds to which part of the promoter? a. -10 consensus sequence b. -35 consensus sequence c. -10 and -35 consensus sequence d. The holoenzyme does not bind to the promoter.

In rho-dependent transcription termination, the rho factor binds to ___________. a. mRNA b. DNA (near the end of the transcribed region) c. RNA polymerase d. sigma subunit

In bacteria, the elongation stage of transcription: a. is carried out by the RNA polymerase core enzyme. b. involves unwinding of only short (~ 18 base pair) regions of the DNA by RNA polymerase. c. generates positive supercoils ahead of the transcription bubble. d. includes frequent pauses by RNA polymerase. e. all of the above.

When a eukaryotic mRNA is hybridized to the complementary DNA, loops of unhybridized DNA are seen. These loops: a. correspond to noncoding regions of the gene. b. are not transcribed into mRNA. c. demonstrate that genes and proteins are not colinear. d. both a and c. e. all of the above.

Which of the following is (are) NOT part of a mature mRNA in eukaryotic cells? a. 5′ UTR b. 5′ cap c. introns d. 3′ UTR e. None of the above are included in the mRNA.

What is the most likely result from mutating a prokaryotic Shine-Dalgarno sequence? a. The translated protein would have different amino acids. b. The mRNA would be less stable. c. The ribosome would not be able to bind to the mRNA. d. None of the above: prokaryotes do not have a Shine-Dalgarno sequence.

Which mRNA processing event adds stability to the mRNA? a. addition of a 5′ cap b. addition of a poly(A) tail to the 3′ end c. addition of a poly(U) tail to the 3′ end d. Both a and b add stability. e. Both a and c add stability.

What kind of RNA functions in pre-mRNA splicing as a component of the spliceosome? a. transfer RNA (tRNA) b. ribosomal RNA (rRNA) c. small nuclear RNA (snRNA) d. none of the above

Which intron component is the first to be cleaved during the splicing process? a. 5′ splice site b. 3′ splice site c. branch point d. depends upon the species

Which arm of tRNA binds to mRNA? a. acceptor arm b. TψC arm c. anticodon arm d. DHU arm e. mRNA arm

All tRNA molecules: a. have a cloverleaf shape for their secondary structure. b. have the sequence AAA at their 3′ end. c. are transcribed as larger precursors that contain one or more introns. d. contain the bases pseudouridine or ribothymidine in place of all uracils. e. share all of the above characteristics.

Which is NOT true of ribosomes? a. They are composed of proteins and ribosomal RNA molecules. b. They are made up of only ribosomal RNA molecules. c. They contain a small subunit and a large subunit. d. RNAs undergo extensive processing before assembly into the ribosome.

Small interfering RNA (siRNA) molecules block gene expression by degrading mRNA or inhibiting transcription. Which genes do they target? a. genes from which they were transcribed b. genes other than those they were transcribed from. c. random genes in the genome. d. transposon genes.