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
Henry III didn’t know much about biology. He went through six wives back in the 1500s, looking for one who could bear him a son.
Henry III didn’t know much about biology. He went through six wives back in the 1500s, looking for one who could bear him a son.
admin
2017-11-17
28
问题
Henry III didn’t know much about biology. He went through six wives back in the 1500s, looking for one who could bear him a son. Scientists now know that it’s the father’s sperm, not the mother’s egg, which determines whether a baby is a boy or a girl. And last week researchers at the Genetics and IVF Institute, a private fertility (生育能力) center in Virginia, announced a new technique that will allow parents to choose the sex of their baby-to-be, before it has even been conceived. The scientist used a tiny laser detector to measure the DNA in millions of sperm cells as they pass single file through a narrow tube, like cattle being herded through a corral (牲口栏). In a study published last week, "girl sperm," which has more DNA—the genetic material—in each cell, was collected, while "boy sperm" was discarded. And when purified girl sperm was used to impregnate (使受孕) a group of mothers, 15 of 17 resulting babies turned out to be girls.
The researchers say that "sex selection" can also double a mother’s chance of having a son and can be used to avoid genetic diseases that affect only one gender, such as hemophilia (血友病). But some experts, like New York University fertility specialist Dr. Jamie Grifo, worry that sex selection could lead to a kind of in uteri (子宫) discrimination, especially in cultures where sons are considered superior to daughters. "It’s valuing one gender over another," Grifo says. "I don’t think that’s something we should be doing." So far, patients at the institute have been asking for both boys and girls, in order to "balance" their families. And some ethics experts say that’s fine, as long as parents are just looking for a little gender variety. "If you have three boys, and you want a girl," says University of Texas reproductive-law professor John Robertson, "that’s not gender bias at all."
The DNAin the sperm cells can be measured _____.
选项
A、in the same way how the cattle are herded
B、when they pass through a tube one behind the other
C、after they pass through a laser tube
D、when they are scanned by a laser detector all at a time
答案
B
解析
推理判断题。解答本题的关键在于堆断single file的意思。该句把精子通过试管的情形与牛群被赶入牲口圈的情形作对比,结合single一词本身的意思,可以推断single file是“一个接一个”的意思,只有选项B能表达这个意思,由此也可否定选项D。选项A最具干扰性,原句是把精子通过试管的情形比作牛群被赶入牲口圈的情形,而选项A说的是测定精子内DNA的方法与放牧的方法相同,显然选项A只是引用了原文的某些词语,但表达的意思与原文却截然不同。
转载请注明原文地址:https://jikaoti.com/ti/PaUFFFFM
0
大学英语四级
相关试题推荐
WhenfamiliesgatherforChristmasdinner,somewillsticktoformaltraditionsdatingbacktoGrandma’sgeneration.Theirtable
ArtificialIntelligence(AI)A)Weoftendon’tnoticeit,butartificialintelligence(AI)isallaroundus.Itispresentinco
ThingsYouCan’tSayinCanadaA)Attackingoursacredcows(thingsorpeoplethatcannotbecriticized)mayturnyouintoo
ThoughtsofsuicidehauntedAnitaRutnamlongbeforeshearrivedatSyracuseUniversity.Shehadahistoryofmentalillnessand
低碳经济(low—carboneconomy)是在保护环境的基础上实现可持续发展(sustainabledevelopment)的经济模式。目前,越来越多国家正向低碳经济转型。中国也不例外。中国过去的发展模式是由高能耗、低成本制造业拉动经济增长。近年来
Ifyouhaveheartproblems,youmightwanttopluginthatiPodorpopinaCDofmellowsongs.Hospitalpatientswithcoronary
SHOPPINGforsaladinsupermarketsistooeasy.Abagofready-washedvegetablescostsonly$3atWalmart,andtakesnotimeto
Domesticviolenceisaseriouscrimecausingserioussocialproblems.Itisviolenceathome,usuallythehusbandbeatinghiswi
A、ItstartsonJune1standlaststhroughtheendofNovember.B、Stormsusuallyforminwinter.C、ItstartsonJune1standla
A、Americanliterature.B、Elementaryeducation.C、Developmentalpsychology.D、Children’sliterature.B女士发现男士也上儿童文学课,感到惊讶,便问男士“你的专
随机试题
兰陵笑笑生所作的《______》是中国第一部文人独创的长篇小说,又是第一部以家庭生活为题材的长篇小说。
A.破裂孔B.卵圆孔C.眶上裂D.圆孔E.颈动脉孔上颌神经出颅于
新生儿低血糖的诊断标准为
限制进出口技术实行目录管理,对于目录范围内的限制进出口技术,实行许可证管理,未经国家许可,不得进出口。
销售的500台计算机的销项税额为( )万元。当月的全部进项税额为( )万元。
某企业为增值税一般纳税人,适用的增值税税率为17%。该企业2016年购入一台需要安装的生产用设备,取得的增值税专用发票上注明的设备买价为50000元,增值税额为8500元,支付的运杂费和保险费为3500元,设备安装时领用工程用材料价值1000元(不含增值税
2009年,某省第二产业增长20%。其中,工业增长21.2%,建筑业增长11.2%。请问2009年该省建筑业占第二产业的比重为多少?()
【C1】______London’sHeathrowAirportisthebusiestinternationalairportinEurope,Amsterdam’sSchipholAirporthasalwayscl
Thegreatchariotofsociety,whichforsolonghadrundownthegentleslopeoftradition,nowfounditselfpoweredbyaninter
A、Byaskinghisfriend.B、Bycallingthetelephoneoperator.C、Byreferringtothereceptionist.D、Byfindingitinthephonebo
最新回复
(
0
)