2022年分子生物学双语习题及精解 .pdf

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1、1 Section C - properties of nucleic acids 1 The sequence 5-AGTCTGACT-3 in DNA is equivalent to which sequence in RNA? A 5-AGUCUGUGACU -3 B 5 -UGTCTGUTC -3 C 5 -UCAGUCUGA-3 D 5- AGUCAGACU-3 2. Which of the following correctly describes A-DNA? A a right-handed antiparallel double helix with 10 bp/turn

2、 and bases lying perpendicular to the helix axis. B a left-handed antiparallel double-helix with 12 bp/turn formed from alternating pyrimidine-purine sequences. C a right-handed antiparallel double 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 1 页，共 28 页 - - - - - -

3、 - - - 2 helix with 11 bp/turn and bases tilted with respect to the helix axis. D a globular structure formed by short intramolecular helices formed in a single-strand nucleic acid. 3. Denaturation of double stranded DNA involves. A breakage into short double-stranded fragments. B separation into si

4、ngle strands. C hydrolysis of the DNA backbone. D cleavage of the bases from the sugar-phosphate backbone. 4. Which has the highest absorption per unit mass at a wavelength of 260 nm? A double-stranded DNA. B mononucleotides. C RNA. D protein. 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - -

5、 名师精心整理 - - - - - - - 第 2 页，共 28 页 - - - - - - - - - 3 5. Type I DNA topoisomeraes . A change linking number by士 2 B require ATP. C break one strand of a DNA double helix. D are the target of antibacterial drugs. Section D - Prokaryotic and eukaryotic chromatin structure 1Which of the following is c

6、ommon to both E. coli and eukaryotic chromosomes? A the DNA is circular. B the DNA is packaged into nucleosomes. C the DNA is contained in the nucleus. D the DNA is negatively supercoiled. 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 3 页，共 28 页 - - - - - - - - - 4

7、2 A complex of 166 bp of DNA with the histone octamer plus histone HI is known as a . . . A nucleosome core. B solenoid. C 30 nm fiber. D chromatosome. 3In what region of the interphase chromosome does transcription take place? A the telomere. B the centromere. C euchromatin. D heterochromatin. 4 Wh

8、ich statement about CpG islands and methylation is not true? A CpG islands are particularly resistant to DNase I. 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 4 页，共 28 页 - - - - - - - - - 5 B CpG methylation is responsible for the mutation of CpG to TpG in eukaryot

9、es. C CpG islands occur around the promoters of active genes. D CpG methylation is associated with inactive chromatin. 5 Which of the following is an example of highly-repetitive DNA? A Alu element. B histone gene cluster. C DNA minisatellites. D dispersed repetitive DNA. Section E - DNA replication

10、 1The number of replicons in a typical mammalian cell is . . . A 40-200. 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 5 页，共 28 页 - - - - - - - - - 6 B 400. C 1000-2000. D 50000-100000. 2. In prokaryotes,the lagging strand primers are removed by . . . A 3 to 5 exonu

11、clease. B DNA ligase. C DNA polymerase I. D DNA polymerase III. 3. The essential initiator protein at the E. coli origin of replication is . . . A DnaA. B DnaB. C DnaC. D DnaE. 4. Prokaryotic plasmids can replicate in yeast cells if they contain a cloned yeast. . . A ORC. 名师资料总结 - - -精品资料欢迎下载 - - -

12、- - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 6 页，共 28 页 - - - - - - - - - 7 B CDK. C ARS. D RNA. Section F - DNA damage, repair and recombination( 此章不考 ) 1. Per nucleotide incorporated, the spontaneous mutation frequency in E. coli is . . . A 1 in 106. B 1 in 108. C 1 in 109. D 1 in 1010. 2.

13、 The action of hydroxyl radicals on DNA generates a significant amount of . . . A pyrimidine dimmers. B 8-oxoguanine. 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 7 页，共 28 页 - - - - - - - - - 8 C O6- methylguanine. D 7-hydroxymethylguanine. 3. In methyl-directed mi

14、smatch repair in E. coli, the daughter strand containing the mismatched base is nicked by . . . AMutH endonuclease. BUvrABC endonuclease. CAP endonuclease. D3 to 5 exonuclease. 4. The excision repair of UV-induced DNA damage is defective in individuals sufferingfrom . A hereditary nonpolyposis colon

15、 cancer. B Crohns disease. C classical xeroderma pigmentosum. D xeroderma pigmentosum variant. Section K - Transcription in prokaryotes 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 8 页，共 28 页 - - - - - - - - - 9 1. Which two of the following statements about transc

16、ription are correct? A RNA synthesis occurs in the 3 to 5 direction. B the RNA polymerase enzyme moves along the sense strand of the DNA in a 5 to 3 direction. C the RNA polymerase enzyme moves along the template strand of the DNA in a 5 to 3 direction. D the transcribed RNA is complementary to the

17、template strand. E the RNA polymerase adds ribonucleotides to the 5 end of the growing RNA chain. F the RNA polymerase adds deoxyribonucleotides to the 3 end of the growing RNA chain. 2. Which one of the following 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 9 页，共

18、28 页 - - - - - - - - - 10 statements about E. coli RNA polymerase is false? A the holoenzyme includes the sigma factor. B the core enzyme includes the sigma factor. C it requires Mg2+ for its activity. D it requires Zn2+ for its activity. 3. Which one of the following statements is incorrect? A ther

19、e are two subunits in the E. coli RNA polymerase. B there is one subunit in the E. coliRNA polymerase. C E. coli has one sigma factor. D the subunit of E. coliRNA polymerase is inhibited by rifampicin. E the streptolydigins inhibit transcription elongation. F heparin is a polyanion, which binds to t

20、he subunit. 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 10 页，共 28 页 - - - - - - - - - 11 4. Which one of the following statements about transcription in E. coli is true? A the -10 sequence is always exactly 10 bp upstream from the transcription start site. B the i

21、nitiating nucleotide is always a G. C the intervening sequence between the -35 and -10 sequences is conserved. D the sequence of the DNA after the site of transcription initiation is not important for transcription efficiency. E the distance between the -35 and -10 sequences is critical for transcri

22、ption efficiency. 5. Which one of the following statements about transcription in E. coli is true? 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 11 页，共 28 页 - - - - - - - - - 12 A loose binding of the RNA polymerase core enzyme to DNA is non-specific and unstable. B

23、 sigma factor dramatically increases the relative affinity of the enzyme for correct promoter sites. C almost all RNA start sites consist of a purine residue, with A being more common than G. D all promoters are inhibited by negative supercoiling. E terminators are often A-U hairpin structures. Sect

24、ion L - Regulation of transcription in prokaryotes 1. Which two of the following statements are correct? A the double stranded DNA sequence that has the upper strand sequence 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 12 页，共 28 页 - - - - - - - - - 13 5-GGATCGATCC

25、-3 is a palindrome. B the double stranded DNA sequence that has the upper strand sequence 5-GGATCCTAGG-3 is apalindrome. C the Lac repressor inhibits binding of the polymerase to the lac promoter. D the lac operon is directly induced by lactose. E binding of Lac repressor to allolactose reduces its

26、affinity for the lac operator. F IPTG is a natural inducer of the lac promoter. 2. Which one of the following statements about catabolite-regulated operons is false? A cAMP receptor protein (CRP) and catabolite activator protein (CAP) are different names for the same 名师资料总结 - - -精品资料欢迎下载 - - - - - -

27、 - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 13 页，共 28 页 - - - - - - - - - 14 protein. B when glucose is present in the cell cAMP levels fall. C CRP binds to cAMP and as a result activates transcription. D CRP binds to DNA in the absence of cAMP. E CRP can bend DNA, resulting in activation of tra

28、nscription. 3. Which one of the following statements about the trp operon is true? A the RNA product of the trp operon is very stable. B the Trp repressor is a product of the trp operon. C the Trp repressor，like the Lac repressor, is a tetramer of identical subunits. D the Trp repressor binds to 名师资

29、料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 14 页，共 28 页 - - - - - - - - - 15 tryptophan. E tryptophan activates expression from the trp operon. F the trp operon is only regulated by the Trp represso 4. Which two of the following statements about attenuation at the tr

30、p operon are true? A attenuation is rho-dependent. B deletion of the attenuator sequence results in an increase in both basal and activated levels of tran- scription from th trp promoter. C the attenuator lies upstream of the trp operator sequence. D attenuation does not require tight coupling betwe

31、en transcription and translation. E pausing of a ribosome at two tryptophan codons in the leader peptide when tryptophan is in short 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 15 页，共 28 页 - - - - - - - - - 16 supply causes attenuation. F a hairpin structure calle

32、d the pnti-terminator stops formation of the terminator hairpin, resulting in transcriptional read-through into the trpE gene, when tryptophan is scarce. Section M - Transcription in eukaryotes 1. Which one of the following statements about eukaryotic RNA polymerases I, II and III is false? A RNA Po

33、l II is very sensitive to -amanitin. B RNA Pol II is located in th nucleoplasm. C RNA Pol III transcribes th genes for tRNA. D eukaryotic cells contain other RNA 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 16 页，共 28 页 - - - - - - - - - 17 polymerases in addition t

34、o RNA Pol I, RNA Pol II and RNA Pol III. E each RNA polymerase contains subunits with homology to subunits of the E. coli RNA polymerase as well as additional subunits， which are unique to each polymerase. F the carboxyl end of RNA Pol II contains a short sequence of only seven amino acids which is

35、called the carboxyl-terminal domain (CTD) and which may be phosphorylated. 2. Which two of the following statements about RNA Pol I genes are true? A RNA Pol I transcribes the genes for ribosomal RNAs. B human cells contain 40 clusters of five copies of the rRNA gene. C the 185, 5.85 and 285 rRNAs a

36、re 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 17 页，共 28 页 - - - - - - - - - 18 synthesized as separate transcripts. D RNA Pol I transcription occurs in the nucleoplasm. E RNA Pol I transcription occurs in the cytoplasm. F rRNA gene clusters are known as nucleolar

37、 organizer regions. 3. Which one of the following statements about RNA Pol I transcription is false? A in RNA Pol I promoters the core element is 1000 bases downstream from the upstream control element (UCE). B upstream binding factor (UBF) binds to both the UCE and the upstream part of the core ele

38、ment of the RNA Pol I promoter. C selectivity factor SLl stabilizes the UBF-DNA complex. D SL1 contains several subunits 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 18 页，共 28 页 - - - - - - - - - 19 including the TATA-binding protein TBP. E in Acanthamoeba there is

39、 a single control element in rRNA gene promoters. 4. Which two of the following statements about RNA Pol III genes are true? A the transcriptional control regions of tRNA genes lie upstream of the start of transcription. B highly conserved sequences in tRNA gene coding regions are also promoter sequ

40、ences. C TFIIIC contains TBP as one of its subunits. D TFIIIB is a sequence specific transcription factor on its own. E in humans 5S rRNA genes are arranged in a single cluster of 2000 copies. 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 19 页，共 28 页 - - - - - - - -

41、 - 20 Section 0 - RNA processing and RNPs 1. Which ribonucleases are involved in producing mature tRNA in E. coli? A RNases A, D, E and F. B RNases D, E, F and H. C RNases D, E, F and P. D RNases A, D, H and P. 2. Most eukaryotic pre-mRNAs are matured by which of the following modifications to their

42、 ends? A capping at the 3 -end cleavage and polyadenylation at the 5-end. B addition of a GMP to the 5-end，cleavage and polyadenylation to create the 3-end. C addition of a guanine residue to the 5-end cleavage and polyadenylation to create the 3-end. D addition of a GMP to the 5-end，名师资料总结 - - -精品资

43、料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 20 页，共 28 页 - - - - - - - - - 21 polyadenylation，then cleavage to create the 3-end. 3. Which one of the following statements correctly describes the splicing process undergone by most eukaryotic pre-mRNAs? A in a two-step reaction, the

44、 spliceosome removes the exon as a lariat and joins the two introns together. B splicing requires conserved sequences which are the 5splice site ， the 3 -splice site the branch-point and the polypurine tract. C the U1 snRNP initially binds to the 5-splice site，U2 to the branchpoint sequence and then

45、 the tri-snRNP, U4, US and U6 can bind. 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 21 页，共 28 页 - - - - - - - - - 22 D in the first step of splicing the G at the 3-end of the intron is joined to the 2 -hydroxyl group of the A residue of the branchpoint sequence to

46、 create a lariat. Section P - The genetic code and tRNA 1. Which of the following list of features correctly apply to the genetic code? A triplet degenerate nearly universal, comma-less, nonoverlapping. B triplet universal, comma-less, degenerate, nonoverlapping. C overlapping, triplet, comma-less,

47、degenerate nearly universal. D overlapping, comma-less nondegenerate nearly universal triplet. 2. Which of the following statements 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 22 页，共 28 页 - - - - - - - - - 23 about tRNAs is false? A most tRNAs are about 76 residue

48、s long and have CCA as residues 74, 75 and 76. B many tRNAs contain the modified nucleosides pseudouridine dihydrouridine ribothymidine and mosme. C tRNAs have a common L-shaped tertiary structure with three nucleotides at one end able to base pair with an anticodon on a messenger RNA molecule. D tR

49、NAs have a common cloverleaf secondary structure containing three single stranded loops called the D-, T- and anticodon loops. 3 Which three statements are true? The aminoacyl tRNA synthetase reaction. 名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 23 页，共 28 页 - - -

50、- - - - - - 24 A joins AMP to the 3 -end of the tRNA. B is a two step reaction. C joins any amino acid to the 2- or 3 -hydroxyl of the ribose of residue A76. D is highly specific because the synthetases use identity elements in the tRNAs to distinguish between them. E joins AMP to the amino acid to