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
90
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
The average modified mouse lived
A:3 years.
B:753 days.
C:More than 3 years.
D:887 days.
答案
D
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/kMMQKKKQ
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
不属于温里剂的方剂是 A.温脾汤 B.四逆汤 C.温胆汤 D.通脉四逆汤
在教育过程中,教师对突发事件作出迅速、恰当的处理被称为教育机智,这反映了教师劳动
代际公平:是可持续发展原则的一个重要内容,主要指当代人为后代人类的利益保存自然资
市场环境因素是影响保险供给的三大因素之一。下列因素中,不属于市场环境因素的是(
占山格
根据《药品经营质量管理规范实施细则》,某药品经营批发企业,有少量的售后退回药品,
某患者,发热39℃,脾肝肿大,颈部淋巴结可触及,血液WBC增多,异型淋巴细胞可检
男,25岁,饭后劳动时突然上腹部持续性剧痛,向背部放射,频繁呕吐,起病后12小时急诊入院。体查:体温37.8℃,脉博120次/分,血压11/8kPa(86...
消化性溃疡最常见的并发症为A.穿孔B.出血C.幽门梗阻D.癌变E.瘘管形成
参与互联网药品交易的医疗机构()。A:可以购买药品,可以上网销售药品B:不能购买药品,可以上网销售药品C:不能购买药品,不得上网销售药品D:只能购买药品,