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
Eat More, Weigh Less, Live Longer Clever genetic detective work may have found out. the reason why a near-starvation diet pr
Eat More, Weigh Less, Live Longer Clever genetic detective work may have found out. the reason why a near-starvation diet pr
admin
2013-10-24
29
问题
Eat More, Weigh Less, Live Longer
Clever genetic detective work may have found out. the reason why a near-starvation diet prolongs the life of many animals.
Ronald Kahn at Harvard Medical School in Boston, US, and his colleagues have been able to extend the lifespan(寿命)of mice by 18 per cent by blocking the. rodent’s(啮齿动物)increase of fat in specific cells. This suggests that thinness-and not necessarily diet-promotes long life in "calorie(热量卡)restricted" animals.
"It’s very cool work, "says aging researcher Cynthia Kenyon of the University of California, San Francisco. "These mice eat all they want, lose weight and live longer. It’s like heaven. "
Calorie restriction dramatically extends the lifespan of organisms as different as worms and rodents. Whether this works in humans is still unknown, partly because few people are willing to submit to such a strict diet.
But many researchers hope they will be able to trigger the same effect with a drug once they understand how less food leads to a longer life. One theory is that eating less reduces the increase of harmful things that can damage cells. But Kahn’s team wondered whether the animals simply benefit by becoming thin.
To find out, they used biology tricks to disrupt the insulin(胰岛素)receptor(受体)gene in lab mice—but only in their fat cells. "Since insulin is needed to help fat cells store fat, these animals were protected against becoming fat, " explains Kahn.
This slight genetic change in a single tissue had dramatic effects. By three months of age, Kahn’s modified mice had up to 70 per cent less body fat than normal control mice, despite the fact that they ate 55 per cent more food per gram of body weight.
In addition, their lifespan increased. The average control mouse lived 753 days, while the thin rodents averaged a lifespan of 887 days. After three years, all the control mica had died, but one-quarter of the modified rodents were still alive.
"That they get these effects by just manipulating the fat cells is controversial, " says Leonard Guarente of the Massachusetts Institute of Technology, who studies calorie restriction and aging.
But Guarente says Kahn has yet to prove that the same effect is responsible for increased lifespan in calorie-restricted animals. "It might be the same effect or there might be two routes to long life, " he points out, "and that would be very interesting. "
The average modified mouse lived
选项
A、3 years.
B、753 days.
C、More than 3 years.
D、887 days.
答案
D
解析
细节题,关键词是average modified mouse,在原文倒数第三段第二句找到“The aver—age control mouse lived 753 days,while the thin rodents averaged a lifespan of 887 days.”这里的改良的mouse就是指比较瘦的,所以这里选D项887 days
转载请注明原文地址:https://kaotiyun.com/show/KdFd777K
本试题收录于:
职称英语综合类B级题库职称英语分类
0
职称英语综合类B级
职称英语
相关试题推荐
HowDidSheConquertheAmericans?African-AmericantalkshowqueenOprahWinfreyistheworld’smostpowerfulcelebrity,acc
Almostalleconomistsagreethatnationsgainbytradingwithoneanother.
Heenduredgreatpainbeforehefinallyexpired.
TheprofoundchangeintheeconomicrelationshipbetweenAmericansandtheirpetshasbeencausedbythefactthat______.The
TheprofoundchangeintheeconomicrelationshipbetweenAmericansandtheirpetshasbeencausedbythefactthat______.Para
A.ReasonsforHIVresistanceB.ImplicationsofchimpanzeeextinctionforhumansC.EffectiveAidstreatmentD.Geneticsimilar
TheNewsIndustryinUSWhydosomanyAmericansdistrustwhattheyreadintheirnewspapers?TheAmericanSocietyofNewspa
"Hidden"SpeciesMayBeSurprisinglyCommonCryptic(隐蔽的;隐藏的)species--animalsthatappearidenticalbutaregeneticallyqui
ComputerMouseThebasiccomputermouseisanamazinglycleverinventionwitharelativelysimpledesignthatallowsustop
随机试题
血清铁蛋白在缺铁的ID期即已降低,是诊断缺铁ID期的敏感指标。
妊娠最早、最重要的症状是()
头围与胸围大致相等的年龄是()
我国B公司以CFR价出口货物一批,装运后即以电报形式向买方发出装船通知,但对方没有收到通知,因而未及时投保,结果船在运输途中沉没,货物全部损失.买方向我方提出索赔,我方应如何处理?如果此事系我方未及时发出装船通知引起的,又该如何处理?
甲公司从事房地产开发经营业务,对投资性房地产采用成本模式进行后续计量。甲公司的财务经理在复核2017年度财务报表时,对以下交易或事项会计处理的正确性难以作出判断:(1)1月1日,因商品房滞销,董事会决定将两栋商品房用于对外出租。1月20日,甲公司与乙公司
社区的基本要素应包括()。
在中国教育制度发展史上,中学阶段最早兼顾升学和就业双重需要的学制是()。
面对大剧院热闹的歌剧景象和观众热烈欢呼的场面,最近,《纽约时报》发表评论,对中国歌剧发展大加赞扬,对此,歌剧理论家、南京艺术学院教授居其宏持不同观点。他认为,衡量一个国家歌剧艺术的发展状况,原创作品质量更具根本性,而当下中国歌剧的原创作品质量普遍较低,戏不
Undercurrentfederallaw,employersareallowedtooffertheiremployeesfreeparkingspacesasatax-freebenefit,buttheyca
Ifyou’vebeenoncampusforverylong,I’mcertainthatyou’vealreadyheardaboutthiscourse.Youmayknowthatlasttermabo
最新回复
(
0
)