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
2023-07-01
21
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/2798307.html
相关试题推荐
Nextmonth,NewYorkstudentsingradesthreethrougheightwilltakethest
Nextmonth,NewYorkstudentsingradesthreethrougheightwilltakethest
Nextmonth,NewYorkstudentsingradesthreethrougheightwilltakethest
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
HenryIIIdidn’tknowmuchaboutbiology.Hewentthroughsixwivesbackin
HenryIIIdidn’tknowmuchaboutbiology.Hewentthroughsixwivesbackin
随机试题
Therateatwhichsoilcanabsorbwater(i)_______withcontinuouswetting,sot
Speech-acttheory*vasfirstdevelopedby______.A、J.L.Austin,B、N.Chomsky.C、
WhenIdecidedtoquitmyfulltimeemploymentitneveroccurredtomethat
下列二叉排序树中,满足平衡二叉树定义的是()。O
根尖周肉芽肿X线片上的表现特点是A.根尖部有一圆形透射影像,边界清晰 B.根尖
学前儿童心理发展的不均衡性表现在哪些方面?
截至2014年12月底,全国实有各类市场主体6932.22万户,比上年增长14.
16周岁以上不满18周岁的公民,以自己的劳动收入为主要生活来源的,视为( )。
广藿香的药理作用有A.促进胃液分泌 B.抗病毒 C.抗螺旋体 D.抗菌
下列与存货相关的会计处理的表述中,正确的有()。A.因台风造成的净损失,计入营
最新回复
(
0
)