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
81
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
Ronald Kahn and his colleagues can make mice live longer by
A:offering them less food.
B:giving them a balanced diet.
C:disrupting the specific genes in their fat cells.
D:Dreventina them qrowinq larger.
答案
C
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/BMMQKKKQ
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
大量出血时,最好及时输入 A、红细胞混悬液 B、血浆增量剂 C、血浆
患者男性,60岁,慢性支气管炎,鼻导管吸氧后病情好转。停用氧时首先应 A、关闭
相对于结构性理财产品,债券型理财产品的优点有()。
主要用于吗啡过量的解救药
关于构造地裂缝,下列说法不正确的是()。 A.是断裂活动的直接产物 B.有
我国《证券法》规定,收购要约的期限不得()。 A.少于30日,并不得超过45
下列叙述中不属于合理用药临床基础的是 A.根据患者的病情检查做出正确诊
有关滴虫性阴道炎,以下哪项错误A.可经性交直接传播,也可经污染的衣物等间接传播B.分泌物灰黄稀薄,有泡沫,阴道黏膜可见散在红色斑点C.常伴有外阴瘙痒,性交痛
共用题干 某银行2010年3月21日向某客户发放汽车贷款20万元,并于当日全部划转指定汽车经销商。该笔贷款期限为6个月,贷款利率5.76%。同年9月11...
下列不是企业的弱势的是()。A:官僚内耗现象产生B:维护成本增加C:减少机会主义行为D:激励机制效力减弱E:信息传递易缺失