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
2024-02-18
1
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. Seientists 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 deteetor to measure the DNA in millions of sperm ceils 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 eaeh 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 gender of the baby is decided by ________.
选项
A、the father’s DNA
B、the mother’s DNA
C、the father’s sperm
D、the mother’s egg
答案
C
解析
该句是一个强调句,明确表明选项c正确。
转载请注明原文地址:https://tihaiku.com/zcyy/3461669.html
相关试题推荐
Afterlookingthroughthestudents’homework,he______tohavethegeographycl
Itisthroughlearningthattheindividual______manyhabitualwaysofreacting
______(正如预料的那样),thenewsaboutthestrikefilteredthrough.Aswasexpected由句中的
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Itisoftenthroughgooddinnersthatonemakesfriends.InJapan,thereare
Itisoftenthroughgooddinnersthatonemakesfriends.InJapan,thereare
随机试题
Itisstability______destroyspeople’sambitionandbarricadespeople’ssteps.A、
[originaltext]W:MikeandIarehavingapartynextweek.Wewonderifyouand
TheU.S.governmentisaskingAmericanstoeatlessandexercisemoreinan
设随机变量X服从参数为2的指数分布,证明:Y=1-在区间(0,1)上服从均匀分布
学而不厌,诲人不倦,从古到今老师的职业道德,这说明职业道德具有()。A.普遍性
架空煤气管道与其他管道共架敷设时的注意事项,下列说法错误的是()。A.煤气管道
下列选项中属于结构良好任务的有()A.写命题作文 B.求边长2厘米的正方形
学堂乐歌《体操一兵操》的曲作者是() A.黄自 B.曾志态 C
关于360度考评法说法正确的是( )。A.360度考评具有全方位、多角度的特点
某工程网络控制室110V直流系统,设计采用51只GFM2型阀控铅酸蓄电池,事故
最新回复
(
0
)