首页
登录
职称英语
Henry III didn’t know much about biology. He went through six wives back in
Henry III didn’t know much about biology. He went through six wives back in
游客
2023-06-24
50
管理
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." [br] 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://tihaiku.com/zcyy/2780025.html
相关试题推荐
HenryIIIdidn’tknowmuchaboutbiology.Hewentthroughsixwivesbackin
HenryIIIdidn’tknowmuchaboutbiology.Hewentthroughsixwivesbackin
Accordingtoarecentstudy,theideaofagingmightlookdifferentthrought
Accordingtoarecentstudy,theideaofagingmightlookdifferentthrought
Accordingtoarecentstudy,theideaofagingmightlookdifferentthrought
Accordingtoarecentstudy,theideaofagingmightlookdifferentthrought
Accordingtoarecentstudy,theideaofagingmightlookdifferentthrought
Accordingtoarecentstudy,theideaofagingmightlookdifferentthrought
TopicLearningThroughTheoryorPractice?Forthispart,youareallowed
【B1】[br]【B12】A、withB、underC、onD、throughAproducemenandwomenwithjudgmen
随机试题
Ihada【16】d______timelastyearwithmyhealth.ForseveralmonthsI【17】su
发生火灾时由火灾自动报警系统或传动管控制,自动开启雨淋报警阀组和启动消防水泵,与
患者,男,45岁。以“间断巩膜黄染伴腹胀2年,加重1周”之主诉入院。患者2年前无
下列哪项属于治则的范畴A.补益 B.解表 C.扶正 D.清热 E.攻下
脾统血的主要作用机制是A.控制血液的流速 B.控制血液的流量 C.控制血液向
不属于临床诊疗道德原则的是( )。A.生命价值原则 B.最优化原则 C.身
红外热像检测待测设备要求中精确测温时,待测设备连续通电时间不小于(____)h,
变电站运行专工负责事故、异常运行的分析报告,提出防止事故对策。
马克思指出:“人是最名副其实的政治动物,不仅是一种合群的动物,而且是只有在社会中
以脏腑病机论杂病的著作是A.《黄帝内经》 B.《难经》 C.《伤寒论》 D
最新回复
(
0
)