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
2023-07-17
69
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/2843679.html
相关试题推荐
Japanisgoingthroughacomplexnationalidentitycrisis.Thatmaybenoba
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
Throughouthistorythebasicunitofalmosteveryhumansocietyhasbeenthe
随机试题
[originaltext]W:Ifyoucanhelpmewiththisjob,Iwouldfinishitbefore5o’
Throughoutevolution,humanshavebeenactive.Ourancestorschasedpreyas
根据中文提示,把对话中缺少的内容写在线上。这些句子必须符合英语表达习惯。打句号的
与国内承包工程相比,国际工程投标报价时,施工机械台班单价的计算通常不考虑()。
含有味蕾的舌乳头有A.叶状乳头 B.菌状乳头 C.丝状乳头 D.以上均含有
中国古代建筑的柱色中等级最高的是( )A.红色 B.金色 C.绿色 D.蓝
心脏骤停元阳暴脱证的中医治法是A.益气复脉 B.开窍醒神 C.回阳固脱 D
下列说法正确的有()。 A.对某一组织而言,质量管理体系是惟一的B-文件控
当财政购买性支出增加时,给社会经济带来的影响有()。A.价格上升,利润提高
编制工程建设监理规划的依据不包括()。A.监理大纲 B.建设工程委托监理合同
最新回复
(
0
)