首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
共用题干 第三篇Eat More, Weigh Less, Live LongerClever genetic detective work may h...
共用题干 第三篇Eat More, Weigh Less, Live LongerClever genetic detective work may h...
admin
2020-12-24
78
问题
共用题干
第三篇
Eat More, Weigh Less, Live Longer
Clever genetic detective work may have found out the reason why a near-starvation diet
prolonas the life of many animals.
Ronald Kahn at Harvard Medical School in Boston,U.S.,and his colleagues nave
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一and not necessarily
diet一Iromotes lonq life in"calorie(热量卡)restricted" animals.
"It's very cool work",says aging researche:Cynthia Kenyon of the University ot
California, San Francisc."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
willina 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一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 mice had
died.but one-quarter of the modified rodents were still alive.
"That they ciet 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."
选项
What does the last sentence in the third paragraph imply?
A:People like to lose weight,but they do not like to eat less.
B:People want to go to heaven,but they do not want to die.
C:Mice will go to heaven if they lose weight.
D:Mice enjoy losing weight.
答案
A
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/RMMQKKKQ
相关试题推荐
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 EconomicReforminChinaMoreUSsinologistshaveexpressedconfidencei...
共用题干 TheJoyofLivingAloneMoreandmoreAmericansarelivingalone.Someli...
随机试题
有些情况下激发冲突是有建设性作用的,以下不是激发冲突方法的是: A、权威性命令
“境内”是指一国政府有效控制和管理的政治领土和主权领土。( )
4岁时应加强的免疫接种是 A.乙肝疫苗 B.麻疹疫苗 C.风疹疫苗 D.
体液总量约占体重的 A.10% B.20% C.40% D.60% E
下列关于计划成本法的描述,正确的有()。
右归丸组成中含有的药物()
社区照顾模式的不足包括( )。 ?
永久性岩层锚杆采用三根热处理钢筋,每根钢筋直径d=10mm,抗拉强度设计值为fy=1000N/mm2,锚固体直径D=100mm,锚固段长度为4.0m,锚固...
为什么有的单位能“三个臭皮匠顶个诸葛亮”,而有的单位则是“三个和尚没水喝”?对待后一种情况,如果你去上任,该怎样处理?
甲公司与银行订立了标的额为8000万元的贷款合同,甲公司董事长美国人汤姆用自己位于W市的三套别墅为甲公司提供抵押担保。贷款到期后甲公司无力归还,银行向法院...