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
54
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
(16-17题共用备选答案) A.化湿法 B.补肾法 C.化瘀法 D.建
功能性月经失调促进排卵的最好方法有 A、人工周期疗法 B、雌激素周期治疗
某工程单元控制室采用控制和动力直流系统分设的方式,动力采用关端电池220V直流系
1985年7月成立的()是勘察设计咨询行业全国性社会团体组织。
管道和设备工程 在城市给水系统中,设置贮水池、水泵的给水方式时,选用恒速水泵的
从内容上看,政府预算是()。
患者,男性,25岁,左侧后牙自发痛。夜间剧痛为主诉就诊,检查:左下8前倾阻生,牙冠与左下7远中牙颈部形成的间隙有较多的食物嵌塞,远中冠周轻度充血,冠周袋无...
问题解决的特点有()。A.目的性B.认知性C.序列性D.独创性
根据企业所得税法律制度的规定,由于技术进步,产品更新换代较快的固定资产,可以缩短折旧年限,但最低折旧年限不得低于法定折旧年限的()。A.50%B.6
下列各项中,应计算缴纳环境保护税的有()。A.依法设立的城乡污水集中处理.生活垃圾集中处理场所超过国家和地方规定的排放标准向环境排放应税污染物的B.其他生产