2005《基因工程》期末试卷A.doc

系 专业 级 班 学号 姓名 装订线泉州师院化学与生命科学学院生物系2007-2008学年度第二学期本科生物科学专业2005级基因工程期末试卷题 序一二三四总成绩统分人成 绩登分人得 分评卷人一、术语解释（30分，每题3分） 1. cDNA： 2. cccDNA:3. 基因文库 :4 生物芯片 :5 .感受态细胞（competent cell） :6 . DNA探针:7. 穿梭载体8. 筛选标记基因9. 蓝-白斑筛选10. 基因操作（gene manipulation）得 分评卷人 二、简答题 （55分） 1. 何谓Klwnow片断？Klwnow片断在基因工程中有哪些用途？（8分） 2、什么是“星星活性”？请简述酶切时如何避免产生星星活性”现象。（8分）3. PCR技术的工作原理是什么？用T载体克隆PCR产物的原理是什么。（8分）4. 请简述在进行RNA操作时该如何避免mRNA降解。（8分）5. 请简述基因的结构对基因操作的影响。（5分）6请简述碱裂解法从大肠杆菌中提取质粒的原理。（8分）7哪些分子生物学的工具酶可用于DNA片断的末端标记？（5分）8基因克隆的基本载体应具备哪些元件？（5分）得 分评卷人三、论述题（10分）典型的DNA重组实验通常包括哪些步骤？ 得 分评卷人五.综合题 (5分 ) 认真阅读后，请回答（可用英文作答）：（1）在94下，DNA以何种形态存在？（1分）（2）退火时，在什么情况下单链的引物和单链的模板之间的氢键才不能断裂（2分）？（3） 72延伸时，DNA聚合酶是以何方向阅读模板链的？DNA聚合酶在引物的哪一端加dNTP？（2分）The cycling reactions of PCR (Polymerase Chain Reaction)1. Denaturation at 94 : During the denaturation, the double strand melts open to single stranded DNA, all enzymatic reactions stop (for example : the extension from a previous cycle). 2. Annealing at 54 : The primers are jiggling around, caused by the Brownian motion. Hydrogen bonds are constantly formed and broken between the single stranded primer and the single stranded template. The more stable bonds last a little bit longer (primers that fit exactly) and on that little piece of double stranded DNA (template and primer), the polymerase can attach and starts copying the template. Once there are a few bases built in, the hydrogen bond is so strong between the template and the primer, that it does not break anymore. 3. extension at 72 : This is the ideal working temperature for the polymerase. The primers, where there are a few bases built in, have a stronger attraction to the template, created by hydrogen bonds, than the forces breaking these attractions. Primers that are on positions with no exact match, get loose again (because of the higher temperature) and dont give an extension of the fragment. The bases (complementary to the template) are coupled to the primer on the 3 side (the polymerase adds d