首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
(1)That smoking causes lung cancer is well established. But what causes smoking? This is the question at the heart of a study pu
(1)That smoking causes lung cancer is well established. But what causes smoking? This is the question at the heart of a study pu
admin
2019-05-24
59
问题
(1)That smoking causes lung cancer is well established. But what causes smoking? This is the question at the heart of a study published in Nature by a group of researchers who work at deCODE, an Icelandic genomics company. They do not, quite, answer it. But they do think they have the answer to the related question of why some smokers smoke in moderation whereas others are rarely found without a fag in their hands—and thus why some people are, genetically speaking, more susceptible to lung cancer than others.
(2)That answer lies in part of human chromosome 15, and depends on what is known as allele T of SNP rsl051730. A SNP, or single-nucleotide polymorphism, to give its full name(the short version is pronounced "snip"), is a place where genomes routinely differ from one another by a single genetic letter.
(3)In this case, the variation happens inside a gene for one of the receptor molecules that nicotine attaches itself to when it produces its buzz. Based on a study of 13,945 Icelandic smokers, deCODE’s researchers showed that having a T in the appropriate part of the gene correlates very strongly indeed with being a heavy smoker. The team estimates that the chance of their being wrong is less than one in a thousand trillion.
(4)Not surprisingly, having the T variant also correlates with the chance of a smoker getting lung cancer. Each copy(there may be none, one or two, since one can come from a person’s father and one from his mother)increases that chance by 30%. The T variant does not, however, increase the likelihood that someone will take up smoking in the first place. That is either a matter of free will or, if it is genetic, is controlled by genes somewhere else. It all looks neat and simple—and extremely plausible. Genes promote smoking; smoking promotes cancer. However, it might be wrong, for another paper in Nature, and a third in its sister journal Nature Genetics, report similar studies that have drawn rather different conclusions.
(5)Paul Brennan and Christopher Amos both agree mat something significant is going on in the part of chromosome 15 studied by deCODE. But they have concluded that genetic variation there acts directly on a person’s susceptibility to lung cancer, rather than acting indirectly by modifying his smoking behavior. That does not mean the gene or genes in question actually cause lung cancer. Rather, it means that they amplify the effects of smoking instead of the amount of smoking.
(6)Like deCODE, both Dr. Brennan(who works at the International Agency for Research on Cancer, in France)and Dr. Amos(who works at the University of Texas)identified rsl051730 as an important SNP. Unlike deCODE, though, both think a second SNP, rs8034191, is involved as well. That, and the fact that the region of chromosome 15 under scrutiny has two other nicotine-receptor genes in it, suggests the situation may indeed be more complex.
(7)On top of this, Dr. Brennan and Dr. Amos both used a different method from deCODE’s. They compared lung-cancer patients directly with otherwise similar cancer-free smokers, in what is known as a case controlled study, and concluded that genetic variants in the nicotine-receptor-rich part of chromosome 15 are changing not smokers’ behavior, but their susceptibility to cancer. Moreover, Dr. Brennan also claims to have discovered an increased susceptibility to lung cancer in non-smokers with the relevant SNPs, though his sample size is small and his result is not supported by Dr. Amos’s work.
(8)These contradictory conclusions are both puzzling and intriguing. DeCODE has one further piece of evidence in its favor. Besides the correlation with lung cancer, the T variant also seemed to correlate with peripheral arterial disease, another common side-effect of smoking. On the other hand, the firm also acknowledges that the link it thinks it has discovered does not account for the whole of the risk of smoking-induced lung cancer. What is not in doubt, however, is that there is some sort of a link between genetics and lung cancer.
(9)That raises interesting issues, particularly as genetic testing becomes easier. DeCODE has already announced it will add rsl051730 to the standard screen it offers to those who wish to know their susceptibility to diseases. The day is not far off, therefore, when those who take the essentially irrational decision to start smoking tobacco will be able to find out in advance exactly how foolish they are being.
Which of the following is INCORRECT about the study of genetics?
选项
A、The different methods adopted have led to the different conclusions that researchers drew.
B、The two groups of researchers have provided evidence in their favor respectively.
C、The role of genetics in smoking and lung cancer has yet to be studied and confirmed.
D、The development of genetic testing has made studies on genetics and lung cancer easier.
答案
A
解析
第7段首句确实提到了布伦南和阿莫斯教授均采用了和deCODE公司不同的研究方法,但第6段首句提到他们均确定rs1051730是一个重要的单核苷酸多态性结构,这一点与deCODE公司观点一致,说明两个研究也存在相同之处,故A中的第二个different表述不对,因此选A。
转载请注明原文地址:https://kaotiyun.com/show/KzbK777K
0
专业英语八级
相关试题推荐
Wehaveseenthatthemerephoneticframeworkofspeechdoesnotconstitutetheinnerfactoflanguageandthatsinglesoundof
Peopleineveryworkplacetalkaboutorganizationalculture,themysteriouswordthatcharacterizesaworkenvironment.Oneof
Dopupilsinschoollearntoreadtheirmothertongueeffectively?Yesandno.Upatthefifthandsixthgrade,reading,onthe
PASSAGETHREEWheredidthesiteoftheoldcoachinginnslocate?
PASSAGETHREEWhyisitrecommendedtostartthetourofLondonfromDickensHouseMuseum?
PASSAGETHREEWhatdoesthefirstclassicexchangeshow?
PASSAGETHREEAccordingtoPlato,whatisthecoreofSocrates’sphilosophy?
QuestionnaireDesignI.Clarifyyourstudygoal—Writedownyourstudygoalbefore【T1】_____【T1】______—Askquestionsthatdire
ChoosingaForeignLanguagetoStudyItisnoteasytochooseaforeignlanguagetostudy,buttherearesomequestionsyoucan
A、Consideration.B、Courage.C、Fairness.D、Awareness.D根据句(6)可知,当主持人问苏珊对于那些要来美国但是并不知道她所说的那些讨论风格的人有什么实际的建议时,苏珊认为意识到讨论风格的不同是最重要的,因此
随机试题
以下不属于新时期德育发展的新主题的是()。
A、剪切应力与剪切速度成正比的流动B、存在屈服值,当剪切应力增加至屈服值时液体才开始流动C、液体黏度随剪切应力增加而增大的流动D、液体黏度随剪切应力增加而下降的流动E、流动曲线表现为环状滞后曲线的流动胀性流
患者,男性,79岁。主诉右下胸部起水疱,剧烈疼痛6天。现病史6天前,右侧下胸部开始疼痛,而后相继起红斑及水疱,沿肋间分布,从前胸蔓延及后胸,未超过正中线,皮损破溃、糜烂,局部脓性分泌物。剧烈疼痛,夜不能寐。患者除作血、尿常规检查,还应该必须完善下列哪项
环境影响按影响的来源分为()。
每张会计凭证的后面至少要附有一张原始凭证。()
下列()集装箱应实施动植物检疫。
约翰逊和施乐斯在1989年提出了战略选择过程的组成部分。下列属于该战略选择过程组成部分的有()。
材料1 统筹是夺取疫情防控和实现今年经济社会发展目标双胜利的科学方法。 这次新冠肺炎疫情,是新中国成立以来在我国发生的传播速度最快、感染范围最广、防控难度最大的一次重大突发公共卫生事件。尽管疫情防控已见成效并呈向好之势,但“行百里者半九十”,不获全
阅读下面的程序段,执行上面的三重循环后,a的值为______。Fori=1To3Forj=1ToiFork=jTo4a=a+1NextkNe
A、 B、 C、 A
最新回复
(
0
)