1) Like replication, transcription also occurs bidirectionally. a) True b) False 2) Which of the following is TRUE for the RNA polymerase activity? a) DNA dependent DNA synthesis b) Direct repair c) DNA dependent RNA synthesis d) RNA dependent RNA synthesis 3) Which of the following ensure stable binding of RNA polymerase at the promoter site a) DNA photolyase b) Sigma factor c) DNA glycosylase d) RecA 4) Name the sigma factor which is used for promoter recognition? a) Sigma 32 b) Sigma 70 c) Sigma 60 d) Sigma 40 5) In a cell, DNA transcription is halted when a) RNA polymerase falls off of the DNA. b) The end of the DNA is reached. c) When a rho site is reached. d) When a stop codon is reached. 6) The complex of RNA polymerase, DNA template and new RNA transcript is called a) transcription bubble b) replication bubble c) a translation bubble d) none of these 7) Rho-dependent termination of transcription in E. coli a) requires ATP b) requires about 50 nucleotides of uncomplexed mRNA c) both (a) and (b) d) removes mRNA and holoenzyme from the DNA 8) Multiple copies of 5S genes, located at a chromosomal site distinct from the other rRNA genes a) are transcribed by rRNA polymerase III and the 5S rRNA b) are transcribed by rRNA polymerase II c) are transcribed by rRNA polymerase I and the 5S rRNA d) are transcribed by DNA polymerase I 9) What is a promoter? a) A specific sequence of DNA to which a catabolic repressor binds b) A specific sequence of DNA to which RNA polymerase binds c) A specific DNA sequence to which a restriction endonuclease binds d) None of the above 10) Transcription factors are a) promoters b) proteins which bind to DNA and regulate transcription c) TATA boxes d) CATT boxes 11) Most transcripts of protein coding genes are cleaved a) at the 3' end just after a poly adenylation signal b) at the 3' end just before a poly adenylation signal c) at the 5' end immediately after a poly adenylation signal d) at the 5' end immediately before a poly adenylation signal 12) Transcription occurs along a ____ template forming an mRNA in the ____ direction. a) 5' to 3'; 5' to 3' b) 5' to 3'; 3' to 5' c) 3' to 5'; 5' to 3' d) 3' to 5'; 3' to 5' 13) Which of the following best describes the key function of helicases during transcription? a) Relief of tension in the DNA strands to prevent breakage. b) Separation of two strands of DNA c) Catalyzing the interaction between transcription factors and the DNA strand. d) Re-annealing of two DNA strands 14) Rho dependent termination mechanism doesn’t reguire____________ a) ATP b) Stem loop structure c) G-C rich stem d) Sigma factor 15) Transcription termination in eukaryotes depends on: a) a hairpin structure b) Rho termination factor c) recognition of a AAUAAA sequence and endonuclease cleavage d) polyadenylation 16) Mature mRNA from a eukaryote would contain each of these features except which of the following? a) exon-encoded RNA b) intron-encoded RNA c) 5' cap d) 3' poly-A tail 17) Which of the following is a type of regulation of gene expression unique to eukaryotes? a) attenuation b) use of alternate σ factor c) chemical modification of histones d) none of the above 18) Which of the following conditions leads to maximal expression of the lac operon? a) lactose present, glucose absent b) lactose present, glucose present c) lactose absent, glucose absent d) lactose absent, glucose present 19) Which of the following is true about an operon? a) encodes for miRNAs. b) contains a promoter unique for each individual gene in the c) Encodes for siRNAs.operator. d) is a region of DNA that is transcribed as a single mRNA 20) Sigma factors present in bacteria are proteins required to a) initiate transcription. b) allow translation to proceed. c) terminate DNA replication. d) terminate DNA replication and initiate transcription. 21) Which of the following is the correct order of binding of general transcription factors to initiate transcription? a) Pol II, TFIID, TFIIB, TFIIH b) TFIID, TFIIB, Pol II, TFIIH c) TFIIB, Pol II, TFIIH, TFIID d) TFIID, TFIIH, TFIIB, Pol II 22) What is the function of TFIIH in the transcription initiation complex? a) binding to the TATA box b) catalyzing the synthesis of RNA c) unwinding the DNA duplex d) all of the above 23) Which of the following is true about an enhancer? a) DNA element that stimulates transcription of eukaryotic b) binds to RNA polymerase and stimulates transcription c) as a binding site for RNA polymerase d) interacts with repressor proteins 24) What is a key structural difference in transcription between prokaryotes and eukaryotes? a) presence of RNA polymarse b) Location of transcription c) presence of introns and exons d) mRNA processing 25) What happens to mRNA in eukaryotes before it is transported out of the nucleus? a) splicing b) capping c) polyadenylation d) all of the above 26) Which of these acts as an inducer of the lac operon? a) lactose b) allolactose c) galactose d) glucose 27) Lac Operon will be turned on when a) Lactose is less than glucose b) Lactose is less in the medium c) Lactose is more than glucose d) Glucose is enough in the medium 28) This condition in lac operon facilitates the condition of lac genes being transcribed at high levels a) low glucose, high lactose b) low glucose, low lactose c) high glucose, high lactose d) high glucose, low lactose 29) What is the consensus sequence of the Pribnow box? a) TATATA b) TATAAAT c) TAATAA d) TTAATA 30) The –35 sequence is highly conserved and has a consensus sequence of ___________ a) TGACAA b) TCGAA c) TGCAAC d) TTGACA 31) The RNA polymerase core enzyme has a high specificity for promoter sites and can perfectly work alone. a) True b) False 32) The –10 promoter region is rich in ______________ bases. a) A,G b) C,T c) A,T d) C,G 33) A stretch of which nucleotide in the DNA acts as the termination signal? a) Poly G b) Poly C c) Poly T d) Poly A 34) Which factor phosphorylates the serine residues in RNA pol II CTD? a) TFIIA b) TFIIB c) TFIIH d) TFIID 35) Capping is done by the addition of __________ a) Methylated A b) Methylated T c) Methylated G d) Methylated C 36) As the polymerase reaches the end of RNA which of the following event does not occur as a response? a) Transfer of Polyadenylation enzyme b) Addition of poly A at the 3’ end c) Cleavage of the RNA d) Termination of transcription 37) Which of the following is not a type of RNA processing? a) Polyadenylation at the 3’ end b) Capping of 5’ end c) Removal of exons d) Splicing 38) Poly (A) tailing of mRNA requires following except: a) DNA template b) Plyadenylation signal at 3' end of mRNA c) poly (A) polymerase d) specific factor 39) The rho factors is structurally and functionally comparable to the _______ a) RNAP b) PCNA c) Sigma 70 d) Helicases 40) Which of the following is a mismatch (the matching items interact with eachother)? a) Core promoter/general transcription factor (GTFs) b) Proximal promoter elements/regulators c) Enhancers/repressors d) UCE/activators

Tutorial II

打印
嵌入

排行榜

视觉风格

选项

切换模板

恢复自动保存：？