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
2024-02-02
16
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] Girl sperm was preferred to boy sperm in the research most probably because _____.
选项
A、girl sperm contains more genetic material
B、more mothers want to have girl babies
C、girl sperm is healthier and more active
D、girl sperm is more easily purified
答案
A
解析
事实细节题。第1段倒数第2句中的由which引导的定语从句表明选项A的叙述正确。
转载请注明原文地址:https://tihaiku.com/zcyy/3414576.html
相关试题推荐
Nextmonth,NewYorkstudentsingradesthreethrougheightwilltakethest
Nextmonth,NewYorkstudentsingradesthreethrougheightwilltakethest
Nextmonth,NewYorkstudentsingradesthreethrougheightwilltakethest
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
HenryIIIdidn’tknowmuchaboutbiology.Hewentthroughsixwivesbackin
HenryIIIdidn’tknowmuchaboutbiology.Hewentthroughsixwivesbackin
HenryIIIdidn’tknowmuchaboutbiology.Hewentthroughsixwivesbackin
随机试题
假定你是李明,根据下面的内容写一封投诉信。1.昨天在超市买的空调不能正常运作;2.要求超市及时提供解决方案,如果不能修理好该空调,将要求退款;3.写信日期
Ifhe(come)________yesterday,Iwouldhavetoldhimallthedetailsregardingt
Spaceisfilledwithradiantenergyandbeyondearth’satmospherethisenerg
X线具有的二象性系指A.穿透性、波动性 B.微粒性、波动性 C.穿透性、感光
室间隔缺损出现青紫时,肺血管的改变为()A.肺小动脉痉挛 B.肺小静脉
通过基金管理人指定的营业网点和承销商的指定账户,向机构或个人投资者发售基金份额的
下列界桩号中,表示同号三立的界桩有()。A:3132001BB:3233001
下列哪些检查项目属于熄灯巡视的内容()(A)检查接地引线是否完好(B)检查表
《建设工程质量管理条例》规定,在正常使用条件下,建设工程的屋面防水工程最低保修期
高桩码头工程施工组织设计编制中,“沉桩施工方案”包括障碍物的探摸清除,(),锤
最新回复
(
0
)