DNA重组技术是将目的DNA在体外重组于载体DNA分子上，构建成重组DNA分子，然后将重组DNA导入宿主细胞中进行大量扩增，最终获得大量同一目的DNA片段。

DNA重组技术又称

A:基因工程 B:蛋白质工程 C:细胞工程 D:酶工程 E:分子工程

DNA重组技术是将目的DNA在体外重组于载体DNA分子上，构建成重组DNA分子，然后将重组DNA导入宿主细胞中进行大量扩增，最终获得大量同一目的DNA片段。

DNA重组技术的应用不包括

A:基因诊断 B:基因治疗 C:转基因和基因敲除 D:单克隆抗体制备 E:基因工程药物,疫苗和抗体

重组DNA技术大致可以用以下几个字简单概括：分（目的基因的分离）,切（限制性内切酶切割目的基因和载体）,接（目的基因和载体连接）,转（连接产物导入受体细胞）,筛（筛选阳性重组子）。

将重组DNA导入大肠埃希菌最常用方法是

A:磷酸钙共沉淀法 B:脂质体法 C:显微注射法 D:噬菌体感染 E:氯化钙法

载体是能携带目的基因进入宿主细胞，实现外源DNA的无性繁殖，或表达有意义的蛋白质的一类DNA分子，是重组DNA技术中一个重要的工具。

载体必须具备的特性中不包括

A:具备自我复制的能力，有较高的拷贝数 B:载体必须具有一个或多个筛选标志 C:能容纳外源性的DNA分子 D:具备一个或多个限制性内切酶的单一识别和切割点 E:必须能够表达外源基因

载体是能携带目的基因进入宿主细胞，实现外源DNA的无性繁殖，或表达有意义的蛋白质的一类DNA分子，是重组DNA技术中一个重要的工具。

人工构建的含有噬菌体DNA cos序列和质粒载体复制子序列的特殊类型的载体称为

A:黏粒载体 B:人工染色体 C:质粒载体 D:噬菌体载体 E:病毒载体

有人测试水体中有机氯农药DDT，经过水体内各级水生生物的食物链，在肉食鱼脂肪中的含量比水体中浓度增大了8.5万倍。我国松花江肇源某江段鲇鱼对甲基汞的浓缩倍数达24万多倍。

该作用可使DDT在环境中经过四级食物链放大后，在鸟类体内DDT含量为水中含量的

A:8万倍 B:10万倍 C:51万倍 D:101万倍 E:151万倍

DNA Fingerprinting

    DNA is the genetic material found within the cell nuclei of all living things. In mammals the strands of DNA are grouped into structures called chromosomes.¹ With the exception of identical siblings (as in identical twins)²，the complete DNA of each individual is unique.

    DNA fingerprinting is sometimes called DNA typing.³ It is a method of identification that compares bits of DNA. A DNA fingerprint is constructed by first drawing out a DNA sample from body tissue or fluid such as hair, blood, or saliva. The sample is then segmented using enzymes, and the segments are arranged by size. The segments are marked with probes and exposed on X-ray film，where they form a pattern of black bars — the DNA fingerprint.⁴ If the DNA fingerprints produced from two different samples match，the two samples probably came from the same person.

    DNA fingerprinting was first developed as an identification technique in 1985. Originally used to detect the presence of genetic diseases⁵，it soon came to be used in criminal investigations and legal affairs. The first criminal conviction based on DNA evidence⁶ in the United Statesoccurred in 1988. In criminal investigations, DNA fingerprints derived from evidence collected at the crime scene are compared to the DNA fingerprints of suspects. Generally, courts have accepted the reliability of DNA testing and admitted DNA test results into evidence. However, DNA fingerprinting is controversial in a number of areas： the accuracy of the results, the cost of testing, and the possible misuse of the technique.   

    The accuracy of DNA fingerprinting has been challenged for several reasons. First, because DNA segments rather than complete DNA strands are "fingerprinted" ； a DNA fingerprint may not be unique ； large-scale research to confirm the uniqueness of DNA fingerprinting test results has not been conducted. In addition，DNA fingerprinting is often done in private laboratories that may not follow uniform testing standards and quality controls. Also, since human beings must interpret the test, human error could lead to false results.

    DNA fingerprinting is expensive. Suspects who are unable to provide their own DNA to experts may not be able to successfully defend themselves against charges based on DNA evidence.

    Widespread use of DNA testing for identification purposes may lead to the establishment of a DNA fingerprint database.

词汇：

figerprinting /ˈfɪŋgəprɪnt/ n. 指纹法，指纹术 

nucleus /"nju:klɪəs/ n. 核，中心
genetic / dʒəˈnetɪk / adj. 遗传的 

mammal /ˈmæml/ n. 哺乳动物
chromosome /ˈkrəʊməˌsəʊm/ n. 染色体 

identification /"aɪˌdentɪfɪˈkeɪʃn/ n. 识别，鉴定，证明
enzyme /"enzaɪm/ n. 酶 

suspect /səˈspekt/ n. 嫌疑犯
fingerprint / ˈfɪŋgəprɪnt / n. 指纹 

saliva /səˈlaɪvə/ n. 唾液
segment /ˈsegmənt/ vt.  分割，分裂；切片，不笨
controversial / ˌkɒntrəˈvɜ:ʃl / adj. 有争议的 

uniform /"ju:nɪfɔ:ml/ adj. 一致的，相同的

注释：

1.In mammals the strands of DNA are grouped into structures called chromosomes.哺乳L动物的 DNA线被组合为称作染色体的各种结构。
2.With the exception of identical siblings (as in identical twins)：生物姊妹体除外（如完全相同的双胞胎）
3.DNA fingerprinting is sometimes called DNA typing. DNA 指纹检查法有时也称 DNA 印记法。
4.The segments are marked with probes and exposed on X-ray film, where they form a pattern of black bars - the DNA fingerprint.切片先用探针做标记，然后在X光片上曝光。胶片上形成 由黑色条纹组成的图案，这就是DNA指纹。
5.Originally used to detect the presence of genetic diseases ： (DNA 指纹法）开始是用来探测遗传病的存在
6.The first criminal conviction based on DNA evidence：基于 DNA 提供证据的首例定罪

Some people believe that using a DNA fingerprint may not be so reliable because____

A:the accuracy of DNA fingerprinting has been challenged B:no private laboratory follows uniform testing standards or quality controls C:mistakes are possible when researchers explain the results of their tests D:suspects may not have enough money to provide their own DNA to law-courts

DNA Fingerprinting

    DNA is the genetic material found within the cell nuclei of all living things. In mammals the strands of DNA are grouped into structures called chromosomes.¹ With the exception of identical siblings (as in identical twins)²，the complete DNA of each individual is unique.

    DNA fingerprinting is sometimes called DNA typing.³ It is a method of identification that compares bits of DNA. A DNA fingerprint is constructed by first drawing out a DNA sample from body tissue or fluid such as hair, blood, or saliva. The sample is then segmented using enzymes, and the segments are arranged by size. The segments are marked with probes and exposed on X-ray film，where they form a pattern of black bars — the DNA fingerprint.⁴ If the DNA fingerprints produced from two different samples match，the two samples probably came from the same person.

    DNA fingerprinting was first developed as an identification technique in 1985. Originally used to detect the presence of genetic diseases⁵，it soon came to be used in criminal investigations and legal affairs. The first criminal conviction based on DNA evidence⁶ in the United Statesoccurred in 1988. In criminal investigations, DNA fingerprints derived from evidence collected at the crime scene are compared to the DNA fingerprints of suspects. Generally, courts have accepted the reliability of DNA testing and admitted DNA test results into evidence. However, DNA fingerprinting is controversial in a number of areas： the accuracy of the results, the cost of testing, and the possible misuse of the technique.   

    The accuracy of DNA fingerprinting has been challenged for several reasons. First, because DNA segments rather than complete DNA strands are "fingerprinted" ； a DNA fingerprint may not be unique ； large-scale research to confirm the uniqueness of DNA fingerprinting test results has not been conducted. In addition，DNA fingerprinting is often done in private laboratories that may not follow uniform testing standards and quality controls. Also, since human beings must interpret the test, human error could lead to false results.

    DNA fingerprinting is expensive. Suspects who are unable to provide their own DNA to experts may not be able to successfully defend themselves against charges based on DNA evidence.

    Widespread use of DNA testing for identification purposes may lead to the establishment of a DNA fingerprint database.

词汇：

figerprinting /ˈfɪŋgəprɪnt/ n. 指纹法，指纹术 

nucleus /"nju:klɪəs/ n. 核，中心
genetic / dʒəˈnetɪk / adj. 遗传的 

mammal /ˈmæml/ n. 哺乳动物
chromosome /ˈkrəʊməˌsəʊm/ n. 染色体 

identification /"aɪˌdentɪfɪˈkeɪʃn/ n. 识别，鉴定，证明
enzyme /"enzaɪm/ n. 酶 

suspect /səˈspekt/ n. 嫌疑犯
fingerprint / ˈfɪŋgəprɪnt / n. 指纹 

saliva /səˈlaɪvə/ n. 唾液
segment /ˈsegmənt/ vt.  分割，分裂；切片，不笨
controversial / ˌkɒntrəˈvɜ:ʃl / adj. 有争议的 

uniform /"ju:nɪfɔ:ml/ adj. 一致的，相同的

注释：

1.In mammals the strands of DNA are grouped into structures called chromosomes.哺乳L动物的 DNA线被组合为称作染色体的各种结构。
2.With the exception of identical siblings (as in identical twins)：生物姊妹体除外（如完全相同的双胞胎）
3.DNA fingerprinting is sometimes called DNA typing. DNA 指纹检查法有时也称 DNA 印记法。
4.The segments are marked with probes and exposed on X-ray film, where they form a pattern of black bars - the DNA fingerprint.切片先用探针做标记，然后在X光片上曝光。胶片上形成 由黑色条纹组成的图案，这就是DNA指纹。
5.Originally used to detect the presence of genetic diseases ： (DNA 指纹法）开始是用来探测遗传病的存在
6.The first criminal conviction based on DNA evidence：基于 DNA 提供证据的首例定罪

This essay talks about DNA fingerprinting concerning the following aspects EXCEPT____

A:legal application of the method B:the way to obtain a DNA sample C:work yet to be done about DNA fingerprinting D:possible danger in drawing a DNA sample from the human body

DNA在染色体的常染色质区压缩多少倍？（）

A:6倍 B:10倍 C:40倍 D:240倍 E:1000倍 F:10000倍

DNA在中期染色体中压缩多少倍？（）

A:6倍 B:10倍 C:40倍 D:240倍 E:1000倍 F:10000倍