It is a wise father that knows his own c

练习题库2022-08-02  20

问题 It is a wise father that knows his own child,but today a man can boost his paternal(fatherly)wisdom–or at least confirm that he's the kid's dad.All he needs to do is shell our$30 for paternity testing kit(PTK)at his local drugstore–and another$120 to get the results.More than 60,000 people have purchased the PTKs since they first become available without prescriptions last years,according to Doug Fog,chief operating officer of Identigene,which makes the over-the-counter kits.More than two dozen companies sell DNA tests Directly to the public,ranging in price from a few hundred dollars to more than$2,500.Among the most popular:paternity and kinship testing,which adopted children can use to find their biological relatives and families can use to track down kids put up for adoption.DNA testing is also the latest rage among passionate genealogists—and supports businesses that offer to search for a family's geographic roots.Most tests require collecting cells by swabbing saliva in the mouth and sending it to the company for testing.All tests require a potential candidate with whom to compare DNA.But some observers are skeptical,"There is a kind of false precision being hawked by people claiming they are doing ancestry testing,"says Trey Duster,a New York University sociologist.He notes that each individual has many ancestors-numbering in the hundreds just a few centuries back.Yet most ancestry testing only considers a single lineage,either the Y chromosome inherited through men in a father's line or mitochondrial DNA,which is passed down only from mothers.This DNA can reveal genetic information about only one or two ancestors,even though,for example,just three generations back people also have six other great-grandparents or,four generations back,14 other great-great-grandparents.Critics also argue that commercial genetic testing is only as good as the reference collections to which a sample is compared.Databases used by some companies don't rely on data collected systematically but rather lump together information from different research projects.This means that a DNA database may have a lot of data from some regions and not others,so a person’s test results may differ depending on the company that processes the results.In addition,the computer programs a company uses to estimate relationships may be patented and not subject to peer review or outside evaluation.28.Skeptical observers believe that ancestry testing fails to__________A.trace distant ancestorsB.rebuild reliable bloodlinesC.fully use genetic informationD.achieve the claimed accuracy

选项 A.trace distant ancestors
B.rebuild reliable bloodlines
C.fully use genetic information
D.achieve the claimed accuracy

答案 D

解析 本题回到文章找到题目涉及到的怀疑观察者对测试的看法,文章在第五段首句谈到“他们在做先祖血缘测试时兜售一种错误的信息”,后文对这一具体信息做出了解释,这种测试只是检测y染色体或mitochondrial DNA,而这种基因往往只来自父亲或母亲,而这些基因仅仅只能揭示一两代人的情况,而3代以后可能会出现6个其他的曾祖父。由此我们可以判断出测试的结果应该是达不到其声称的准确性,故答案为D。
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