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
53
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. "
Ronald Kahn and his colleagues can make mice live longer by
选项
A、offering them less food.
B、giving them a balanced diet.
C、disrupting the specific genes in their fat cells.
D、preventing them growing larger.
答案
C
解析
细节题,这里的定位词可以是Ronald Kahn and his colleagues和mice,在原文第二段中找到“Ronald Kahn at Harvard Medical School in Boston,US,and his colleagues have been able toextend the lifespan(寿命)of mice by 18 per cent by blocking the rodent’s(啮齿动物)increase of fat inspecific cells.”其中“extend the lifespan(寿命)of mice”是挺长老鼠寿命的意思。这里的“by blockingthe rodent’s…”是by引导的方式状语从句。答案就在此。这里的“fat in specific cells”恰好对应了选项C的“specific genes in their fat cells”。故选C。
转载请注明原文地址:https://kaotiyun.com/show/sOFd777K
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
TechnologyTransferinGermanyWhenitcomestotranslatingbasicresearchintoindustrialsuccess,fewnationscanmatchGer
Almostalleconomistsagreethatnationsgainbytradingwithoneanother.
ElectromagneticEnergy1.Whitelightseemstobeacombinationofallcolors.Theenergythatcomesfromasourceoflighti
TheprofoundchangeintheeconomicrelationshipbetweenAmericansandtheirpetshasbeencausedbythefactthat______.The
TheNewsIndustryinUSWhydosomanyAmericansdistrustwhattheyreadintheirnewspapers?TheAmericanSocietyofNewspa
TheNewsIndustryinUSWhydosomanyAmericansdistrustwhattheyreadintheirnewspapers?TheAmericanSocietyofNewspa
TheNewsIndustryinUSWhydosomanyAmericansdistrustwhattheyreadintheirnewspapers?TheAmericanSocietyofNewspa
TheNewsIndustryinUSWhydosomanyAmericansdistrustwhattheyreadintheirnewspapers?TheAmericanSocietyofNewspa
"Hidden"SpeciesMayBeSurprisinglyCommonCryptic(隐蔽的;隐藏的)species--animalsthatappearidenticalbutaregeneticallyqui
ComputerMouseThebasiccomputermouseisanamazinglycleverinventionwitharelativelysimpledesignthatallowsustop
随机试题
矩形牙嵌离合器的齿侧通过工件轴线的切向平面。()
男,65岁。排尿困难2年,尿线细,射程短,排尿时间延长。1天前因感冒后突发不能自行排尿,下腹区胀痛难忍。应先行
【2019年真题】在喷漆厂房内,硝基物质的漆料和稀释剂喷成雾状扩散后能与空气形成爆炸性混合物,遇火源便会发生燃烧爆炸。下列关于喷漆作业及场所安全要求的说法中,错误的是()。
灌溉分水闸招标时共有甲、乙、丙、丁四家单位购买了招标文件,其中甲、乙、丙参加了由招标人组织的现场踏勘和标前会,现场踏勘中甲单位提出了招标文件中的疑问,招标人现场进行了答复,根据有关规定,招标人应将解答以书面方式通知()。
下列非关税壁垒的特点说法错误的是()。
某商厦有一辆客货两用汽车,为顾客送货,乘客座位4人,排量1.0升,整备质量2.1吨。当地省政府规定,该排量乘用车车船税年税额为200元/辆,相同整备质量的货车车船税年税额为40元/吨,商厦每年应缴纳车船税()元。
加法的学习影响着乘法的学习,而乘法的学习反过来也影响着对加法的重新理解,这在心理学中叫——。
ToMissDoughty16September1962,SundayMydear,Well,hereweare-butnothere.YouareinPrinceton,andmeinQuogu
Microsoftemployeesdonotrecognizethemselvesinthegovernment’ssuitsintheMicrosoftcafeteriainRedmond,Washington.The
Reebokexecutivesdonotliketoheartheirstylishathleticshoescalled"footwearforyuppies(雅皮士•少壮高薪职业人士)".Theycontendth
最新回复
(
0
)