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新东方网为大家带来2020托福听力练习：蛋白质测试补充DNA分析（下载），希望对大家有所帮助!更多内容请随时关注新东方网!
DNA analysis is a staple of crime scenes—and crime shows, like HBO's The Night of or the old standby, CSI:
"We just need to get this to the DNA lab, confirm it's the victim's blood. And then, case closed."
And it's not just for crime: DNA sequencing also helps determine our relationship to Neandertals, and our primate cousins.
Problem is, DNA's a relatively fragile molecule—it doesn't last forever. What's more sturdy is protein. So now researchers have come up with a way to use protein in a similar way to DNA: to link an individual to a piece of evidence or to determine ethnic background.
The protein source these scientists studied was human hair, from 76 individuals of European-American, African-American and Kenyan descent. And they determined that the variation of a couple hundred proteins in a person's hair could be enough to single her out from a group of one million individuals.
The way it works is that proteins are made according to the instructions in DNA. So one individual's genetic variations can result in slightly different proteins being made, compared to another individual. And by determining the protein composition, the scientists can then extrapolate info about the DNA. The results are in the journal PLoS ONE.
The researchers say the technique still is not ready for prime-time—ideally the process needs to be more sensitive, to avoid consuming valuable crime scene or archaeological samples in the analysis. And the statistics behind the technique need to be validated, too. But someday, they say, it could come within a hair of DNA analysis.
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DNA分析是犯罪现场和犯罪片采用的主要方法，就像家庭影院频道(HBO)的电视剧《罪恶之夜》和老牌美剧《犯罪现场调查》中经常出现的场面。
“我们只需要将这个送到DNA实验室，确认这是受害者的血迹。然后就可以结案了。”
但是，DNA分析不仅仅只是用于犯罪调查，DNA序列还可以帮助确定我们与尼恩特人以及与灵长类动物的关系。
问题是，DNA是一个相对脆弱的分子，其并不会永远存在。更加坚固的是蛋白质。所以现在研究人员提出了一种利用蛋白质的新方法，该种方法与DNA的使用方法非常相似：将个体同证据联系起来，或是确定种族背景。
这些科学家研究的蛋白质来自人类的头发，这些头发采集自欧裔美国人、非洲裔美国人以及肯尼亚的76个个体。科学家发现，一个人头发中数百个蛋白质的变化足以将该个体与其他100百万个个体相区分。
这种方法就是根据DNA的指令来操作蛋白质。所以，与其他个体相比较，一个个体的基因变异会产生略有不同的蛋白质。通过确定蛋白质的组成，科学家可以推断出DNA的信息。这项研究结果发表在《公共科学图书馆·综合》杂志上。
研究人员表示，这项技术尚未成熟，在理想情况下，该过程需要更加的谨慎，以避免在分析中浪费宝贵的犯现场或其他考古样本。另外，该技术的支持数据也还需要验证。但是，科学家表示，有朝一日可以实现通过头发来验证DNA。
重点讲解：
1. come up with 想出，提出(计划、想法等);
例句：I had a hard time trying to come up with an idea.
为了想出主意我苦思了半天。
2. single out 单独挑出;特别选出;
例句：He was singled out for special training.
他被选拨出来接受专门训练。
3. according to 依据，根据，依照 (原则等);
例句：He ranged the books according to size.
他照大小顺序排列这些书。
4. result in 导致;引起;造成;
例句：It resulted in a diminished output.
这导致了减产。
5. compared to 与…相比;和…比起来;
例句：The cost is just peanuts compared to what you get from the money.
和你投资所获得的利益相比，这点成本就不算什么。
以上是新东方网为大家带来的2020托福听力练习：蛋白质测试补充DNA分析（下载），希望认真积极的备考，早日取得优异的成绩。更多内容请随时关注新东方网!
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