08-09分子生物学期末试卷及答案.doc

福建农林大学期末考试试卷2008 2009学年第 学期课程名称： 分子生物学 考试时间 120 分钟 专业 年级 班 学号 姓名 题号一二三四总得分得分评卷人签字复核人签字得分一、填空题（每空0.5分，共10分）1、The enzymes needed in the bacterial DNA replication are topoisomerase, helicase, _, DNA polymerase and _.（引物酶；DNA连接酶）2、There are five families of histones:_, _, _ and _, known as the core histones, and H1.（H2A；H2B；H3；H4）3、The holoenzyme of E.coli RNA polymerase is_，the core enzyme is made up of _，while the_ factor has the ability to recognize specific binding sites.（2；2；）4、There are two kinds of mutagens, one is physical mutagens, such as_，the other is chemical mutagens, such as_.（各种射线；碱基类似物/烷化剂/亚硝酸/EB）5、The two-dimensional structure of tRNA is . And the three-dimensional structure of tRNA is . （三叶草型、L型）6、 was suggseted by Crick to explain the redundancy of the genetic code.（摆动假说）7、The start codon is . There are three stop codons: , , .（ATG或AUG、TAA或UAA、TAG或UAG、TGA或UGA）8、 site is where incoming aminoacyl-tRNA molecules bind, and site is where the growing polypeptide chain is usually found.（A、P）得分二、名词解释（每小题2分，共30分）1、semi-conservative replication：半保留复制，亲代双链DNA以每条链为模板，按碱基配对原则各合成一条互补链，这样一条亲代DNA双螺旋，形成两条完全相同的子代DNA螺旋，子代DNA分子中都有一条合成的“新”链和一条来自亲代的旧链。2、Tm：核酸热变性温度范围的中点。3、asymmetry of transcription：转录的不对称性，指双螺旋的DNA进行转录时只有一条链能被转录，另一条链可能起调节作用。4、transition：在基因突变中，一个嘌呤被另一个嘌呤所代替或一个嘧啶被一个另嘧啶所代替的现象。5、exon：外显子，指真核生物基因中，含有蛋白质编码信息区段、在成熟mRNA的加工过程中被保留下来的部分。6、transposon：转座子，基因组上一些可由一个位置移动到另一位置的核酸序列。7、operon：原核基因表达调控的单位，包括启动子、操纵基因和一系列功能相关的结构基因。8、Synonymous codon：编码同一氨基酸的密码子。9、Ribosome：核糖体，蛋白质合成的场所。10、Shine-Dalgarno sequence ：SD序列，由Shine和Dalgarno发现原核生物起始密码子上游813个nt的保守多嘌呤序列，与核糖体16S小亚基的特定序列碱基配对，相对于起始密码子正确定位核糖体，保证翻译的准确。11、housekeeping gene：生物体不同发育时期所有类型细胞中均保持表达状态的基因。12、Ribozyme：核酶，能够催化特定生化反应的RNA分子。13、Chaperone：分子伴侣，帮助蛋白质分子形成正确空间构象的辅助分子。14、DNA clone：DNA克隆，将片段相对较短的目的核酸片段与能进行独立复制的载体连接形成重组DNA，重组DNA能够在寄主细胞内增殖，从而获得大量的目的核酸片段。15、phage：侵染细菌的病毒。得分三、单项选择题（每小题1分，共15分）（ D ）1、DNA replication in eukaryotes:A. usually starts at the same place every timeB. only involve 2 different DNA polymerasesC. is faster than in bacterial DNA replicationD. all of the above are false（ D ）2、Which of the following are true statements regarding telomeres:A. they stabilize linear chromosomesB. they consist of a short repeating sequenceC. they are located at the chromosome endsD. all of the above are true（ C ）3、Mismatches produced from replication errors are first recognized by _ for the purposes of repair.A. MutH B. MutM and MutLC. MutL and MutS D. Exonuclease I（ B ）4、Transcription in prokaryotes and the eukaryotic nucleus:A. is catalyzed by the same enzymeB. involves Watson-Crick type pairing of nucleotidesC. requires a primerD. proceeds from 3 to 5（ C ）5、Which of the following is an example of highly-repetive DNA?A. Alu element B. Histone gene clusterC. Minisatellite DNA D. KpnI family（ C ）6、Which of the following is not involved in homologous recombination in E. coli that we studied in class:A. RecA B. RecBCD C. RecQ D. RuvA（ B ）7、Regulation of the Lac operon is belong to:A. repression of negative control B. induction of negative controlC. repression of positive control D. induction of positive control（ D ）8、which of the following descriptions of subunits of DNA polymerase III holoenzyme is true？A. the subunits clamp the polymerase to the DNAB. the subunits link the two catalytic cores togetherC. the subunits contribute the DNA polymerase activityD. all of the above are ture（ B ）9、Nuclear mRNA splicing is performedA. in nucleosomes B. in spliceosomesC. in the nucleolus C. in ribosome（ C ）10、Cap functions not include A. enhancing splicing of the first intron B. enhancing translation of the mRNA C. enhancing degradation of the mRNA in the cytoplasm D. enhancing the stablitity of the mRNA（ D ）11、Which of the following is true of the genetic codeA. it is read 3 nucleotides at a timeB. it is not overlappingD. it is degenerate (more than one triplet codes for most amino acids)D. a and b are true（ A ）12、The region(s) of tRNA recognized by amino-acyl tRNA synthetases (so that they can charge the right tRNA) isA. the CCA B. the D loop C. the anticodon C. the T or pseudouridine loop（ C ）13、In nuclear mRNA splicing, the intron is released as a A. circular RNA B. linear RNA C. lariat RNA D. a “Y” RNA（ B ）14、The first and main polyadenylation signal is foundA. 20-30 bp from the ORFB. 20-30 bp from the polyadenylation siteC. 20-30 bp from the promoter siteD. 20-30 bp from the end of the RNA（ A ）15、During initiation step of the translation in prokaryotes, the components involved are A. ribosome, mRNA, initiator tRNA charged, initiator factors, GTP B. ribosome, mRNA, initiator tRNA charged, initiator factors, ATP C. ribosome, mRNA, initiator tRNA charged, initiator factors, CTP D. ribosome, mRNA, initiator tRNA charged, initiator factors, TTP得分四、问答题（45分）1、Please illuminate the main content of central dogma and draw the sketch map.（10 points）DNA是生物遗传的主要物质基础。遗传信息以特定的脱氧核苷酸序列储存在DNA分子中（1分）。DNA能准确地自我复制（1分），并把遗传信息转录到mRNA分子上（1分），然后通过mRNA翻译成为具有特定氨基酸顺序的蛋白质（1分），由蛋白质行使各种生物学功能。Crick把这种遗传信息的流动称为分子遗传的中心法则。后来人们又发现反转录病毒可以其RNA作为模板指导合成DNA（1分）；某些病毒RNA可以进行自我复制，即以自身RNA为模板，合成子代RNA（1分）。这些发现是对中心法则的补充和发展。 DNA RNA 蛋白质 （4分）2、what is the promoter？Please describe the most conserved structure of E.coli promoters.（7 points）定义：RNA聚合酶特异性结合和起始转录所需的保守序列。（2分）结构：TTGACA1618bpTATAAT58bpG/A -35序列 -10序列 +1 1分 1分 1分 1分 1分3、Please briefly describe the structure features of the Watson-Crick double-helix.（7 points）（1）两条单链，右手螺旋，反向平行，大沟和小沟；（2分）（2）嘌呤和嘧啶位于螺旋的内侧，磷酸和脱氧核糖基位于螺旋外侧，彼此以3 ,5 -磷酸二酯键连接，形成DNA分子的骨架。（1.5分）（3）直径2 nm，10bp/螺旋，螺距3.4nm。（1.5分）（4）碱基互补配对存在。（2分）4、What are the characters of expression vectors? (5 points)（1）能够进行独立于基因组的自我复制 （1分）（2）容易从细胞中分离提取 （1分）（3）含有