文档收集于互联网，已重新整理排版.word版本可编辑,有帮助欢迎下载支持. 1文档来源为:从网络收集整理.word版本可编辑. Section A - Cells and macromolecules 1．The glycosylation of secreted proteins takes place in the . . . A mitochondria. B peroxisomes. C endoplasmic reticulum. D nucleus. 2．Which of the following is an example of a nucleoprotein? A keratin. B chromatin. C histone. D proteoglycan. 3．Which of the following is not a polysaccharide? A chitin. B amylopectin. C glycosaminoglycan. D glycerol. 4. Transmembrane proteins A join two lipid bilayers together. B have intra- and extracellular domains. C are contained completely within the membrane. D are easily removed from the membrane. Section B - Protein structure 1. Which of the following is an imino acid? A proline. B hydroxy lysine. C tryptophan. D histidine. 2． Protein family members in different species that carry out the same biochemical role are described as . . . A paralogs. B structural analogs. C heterologs. D orthologs. 3. Which of the following is not a protein secondary structure? A α-helix. B triple helix. C double helix. D ß-pleated sheet. 4． In isoelectric focusing, proteins are separated . A in a pH gradient. B in a salt gradient. C in a density gradient. D in a temperature gradient. 5．Edman degradation sequences peptides . . . 文档收集于互联网，已重新整理排版.word版本可编辑,有帮助欢迎下载支持. 1文档来源为:从网络收集整理.word版本可编辑. A using a cDNA sequence. B according to their masses. C From the C-terminus to the N-terminus. D from the N-terminus to the C-terminus. 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 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 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 preakage into short double-stranded fragments. B separation into single 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. 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 1．Which of the following is common 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. 2．A compl 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. 文档收集于互联网，已重新整理排版.word版本可编辑,有帮助欢迎下载支持. 1文档来源为:从网络收集整理.word版本可编辑. D chromatosome. 3．In what region of the interphase chromosome does transcription take place? A the telomere. B the centromere. C euchromatin. D heterochromatin. 4． Which statement about CpG islands and methylation is not true? A CpG islands are particularly resistant to DNase I. B CpG methylation is responsible for the mutation of CpG to TpG in eukaryotes. 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 1．The number of replicons in a typical mammalian cell is . . . A 40-200. B 400. C 1000-2000. D 50000-100000. 2. In prokaryotes,the lagging strand primers are removed by . . . A 3' to 5' exonuclease. 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. Which phase would a cell enter if it was starved of mitogens before the R point? A G1. B S. C G2. D G0. 5. Which one of the following statements is true? A once the cell has passed the R point, cell division is inevitable. B the phosphorylation of Rb by a G1 cyclin-CDK complex is a critical requirement for entry into S phase . C phosphorylation of E2F by a G1 cyclin-CDK complex is a critical requirement for entry into S phase. D cyclin D1 and INK4 p16 are tumor suppressor proteins. 6. In eukaryotes, euchromatin replicates predominantly...