首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Dolly the clone (克隆羊多利) was born a lamb, but her chromosomes (染色体) tell a differen story. They say she was already a few years o
Dolly the clone (克隆羊多利) was born a lamb, but her chromosomes (染色体) tell a differen story. They say she was already a few years o
admin
2012-07-18
38
问题
Dolly the clone (克隆羊多利) was born a lamb, but her chromosomes (染色体) tell a differen story. They say she was already a few years old by the time she left her mother’s womb.
Scientists at the Roslin Institute in Scotland finally took a close look at Dolly’s chromosomes and found that their ends, or telomeres(端粒—染色体端位上的着色点), are shorter than those of normal sheep of Dolly’s age. Telomeres, scientists think, are a major factor in aging—the shorter they are, the closer the cell is to dying.
The scientists also looked at the telomere length of two other sheep, one cloned from a 9-day-old embryonic cell(受孕的胚胎细胞) and the other from a 25-day -old fetal cell. The sheep cloned from the 9-day -old cell had the longest telomeres of the three, suggesting that the key factor in determining telomere length seems to be the number of divisions the cell undergoes before being cloned.
All three clones appear to be healthy, and whether the animals will have a shorter life span as a result of their shorter telomeres remains an open question. But the shortened telomeres do suggest that genetic blueprints may wear out over time, making it impossible to clone an animal endlessly.
Dolly is exactly the same as an ordinary lamb.
选项
A、Right.
B、Wrong.
C、Doesn’t say.
答案
B
解析
克隆羊多利尽管是一只羊,但出生时已经有好几岁了,因此与普通羊并不完全相同。
转载请注明原文地址:https://kaotiyun.com/show/92ld777K
本试题收录于:
公共英语一级笔试题库公共英语(PETS)分类
0
公共英语一级笔试
公共英语(PETS)
相关试题推荐
I’moldenoughtowash______clothesbymyself.Youcanjustwash______.
Whatarethetwopersonstalkingabout?
Arabbitcantellotherssomethingby______.Somebirdscanmakeseveraldifferentsounds,eachwithmeaning______.
[A]stamp[B]zoo[C]blackboard[D]train[E]postoffice[F]park[G]bank
Theplacewherepeoplegotoseethefilm.Theplacewherepeoplegotoseethedoctor.
Heforgot______thebottlefirstbefore______themedicine.
Mr.Wangdoesn’tworkinthatfactoryanylonger.Mr.Wang______workinthatfactory.
Whenthestudentscameintotheclassroom,theteacher______ontheblackboard.
LastSundayIsawtheworststorm.Itcamesuddenlyandwentonformorethanthreehours.Afterlunch,Iwentintomyroom
Sallywasfourteen.Shestudiedinamiddleschool.Shelikeddancingandsingingandspentalotoftimeonthem,butshehated
随机试题
制定《期货从业人员管理办法》的目的是( )。
Therewasatimeintheearlyhistoryofmanwhenthedayshadnonames!Thereasonwasquitesimple:Menhadnotinventedthew
下列国际直接投资的形式中,可以不建立具有法人地位的经济实体的是
确诊菌痢最可靠的依据是:()
A.急性重型肝炎B.亚急性重型肝炎C.胆道阻塞D.寄生虫感染E.慢性酒精中毒坏死后性肝硬化的原因
解除尿潴留时,护理措施不当的是
一个Rh溶血症患儿,出现嗜睡、尖声哭叫、肌张力下降,胆红素上升至342μmol/L,该患儿可能发生了
中国文字著作权协会的性质描述正确的是()。
某食品公司工会向公司提出了签订集体合同的要求,公司表示同意。随后,工会与公司拟订了集体合同草案,工会还组织职工对集体合同草案进行了讨论。在工会与公司举行了合同签订仪式后,工会将集体合同报送了劳动行政部门。根据国家有关规定,集体合同()。
下列各项中,不会引起资产负债表中负债金额增加的是()。
最新回复
(
0
)