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
2023-06-28
63
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/2789005.html
相关试题推荐
Sixyearsago,aMiamiwomanwalkingthroughthehallofanofficebuilding
Sixyearsago,aMiamiwomanwalkingthroughthehallofanofficebuilding
Sixyearsago,aMiamiwomanwalkingthroughthehallofanofficebuilding
HenryIIIdidn’tknowmuchaboutbiology.Hewentthroughsixwivesbackin
HenryIIIdidn’tknowmuchaboutbiology.Hewentthroughsixwivesbackin
OlderAmericansareheadingintoandthroughretirementwithaboatload(船的载货
OlderAmericansareheadingintoandthroughretirementwithaboatload(船的载货
OlderAmericansareheadingintoandthroughretirementwithaboatload(船的载货
[originaltext]Literatureprovidesalensthroughwhichreaderslookatthe
Whenyourunyourhandsthroughyourlover’shair,you’reprobablynotthink
随机试题
Aperson’shomeisasmuchareflectionofhispersonalityastheclotheshe
[originaltext]W:Justimagine!Wehavetofinishreading300pagesbeforeMonda
Forthispart,youareallowed30minutestowriteashortessay.Youshouldsta
如图所示的结构,截面K的剪力影响线是( )。 A、曲线 B、向右上方
以下对居住区绿地规划基本要求的叙述中,哪一条是不正确的?( )A.集中与分散相
结构化设计(StructuredDesign,SD)是一种面向(请作答此
肺根不包括肺动脉。()
慢性胃体胃炎的病因是A.过量饮酒 B.十二指肠反流 C.免疫因素 D.幽门
不寐
甲企业与乙企业相邻,甲企业发生火灾后乙企业立即给予支援,最终在公安消防队的带领下
最新回复
(
0
)