单选题 DNA fingerprinting is used to determine where particular genetic material came from, that is what person or group of people's material is mostly likely to come from. Only 1% of our DNA differs from other individuals since 99% of human DNA is identical. That 1% though can allow scientists to differentiate its origin.
DNA fingerprinting is most commonly used to determine our heredity. When used alongside more traditional sociological methodologies, DNA fingerprinting can be used to find out exactly where we came from, in some cases, which tribe. However, DNA fingerprinting cannot discriminate between identical twins.
Most people are aware of the use of DNA fingerprinting in forensic medicine. Samples gathered at a crime scene can be compared with the DNA of a suspect to prove his or her presence at or involvement with the crime. The problem is that DNA bases only hold the DNA of people who have already been convicted of a crime. They do not contain the DNA of whole populations so it impossible to use this technique to track down suspects that are nor present in the database. However this might change. If governments replace photograph ID cards to that of DNA fingerprint ID cards, then it will be far easier to track down anyone within a nation's population.
DNA fingerprinting can also help us to predict our future health. It is often used to track down the genetic basis of inherited diseases. If there is a particular, recurring pattern in different patients, scientists can narrow down which gene or genes might be involved. It can also be used to screen parents and fetuses for the presence of inherited abnormalities, such as Huntington's disease or muscular dystrophy, so appropriate advice can be given and precautions taken as needed.
The use of DNA fingerprinting and genetic screening is fast in changing society and the way we treat illnesses, track down criminals and soon, identify the public. It is a science that has dramatically changed society and continues to make great contributions to health and science in all fields.

单选题 What is the main purpose of DNA fingerprinting?

【正确答案】 D

【答案解析】细节题。题干问DNA指纹识别法的主要目的是什么?原文首段第一句，“DNA fingerprinting is used to determine where particular genetic material came from, that is what person or group of people's material is mostly likely to come from.”意为DNA指纹识别法被用来判断特定遗传物质的来源，即这个物质最有可能来自哪个人或哪群人。选项D，用来辨认谁拥有某一特定的基因，为近义替换。选项A，区别不同国家的人，不是主要用途。选项B，分析人类的进化；选项C，观察基因的发展。均未在文中提及。

单选题 Which one of the following is TRUE according to the passage?

【正确答案】 B

【答案解析】细节题。根据首段第二句，意为人类DNA的99%是一样的，只有1%有个体差异。可知选项A有误。第二段第二句When used alongside more traditional sociological methodologies...，意为“当DNA指纹识别法和更传统的社会学方法论相结合时，才能确切查明我们的来历。”由此可知选项C错误。原文第二段第一句，DNA指纹识别法被常常用于遗传的鉴定。并不是仅仅用于遗传鉴定，所以选项D错误。DNA指纹识别法不能鉴别双胞胎，与原文第二段最后一句意思相符。因此，B为正确答案。

单选题 Why is it more convenient for government to replace photograph ID cards with DNA fingerprint ID cards?

【正确答案】 A

【答案解析】细节题。题干问为什么政府将有照片的身份证换成有指纹的身份证会更方便?根据关键词photograph ID cards定位于原文第三段。第三段开始讲，指纹识别法只能够识别出那些有过犯罪记录的人，而无法识别所有人。解决这一问题的方法便是，将身份证上的照片换成指纹，政府便容易追捕罪犯了。因此，正确答案是选项A。