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
专升本
For many years, scientists couldn’t figure out how atoms and molecules(分子)on the Earth combined to make living things. Plants, f
For many years, scientists couldn’t figure out how atoms and molecules(分子)on the Earth combined to make living things. Plants, f
admin
2019-11-21
17
问题
For many years, scientists couldn’t figure out how atoms and molecules(分子)on the Earth combined to make living things. Plants, fishes, dinosaurs(恐龙), and people are made of atoms and molecules, but they are put together in a more complicated way than the molecules in the primitive ocean. What’s more, living things, that have energy and can reproduce on the Earth four billion years ago were lifeless.
After years of study, scientists figured out that living things, including human bodies, are basically made of amino acids and nucleotide(氨基酸与核苷酸)bases. These are molecules with millions of hydrogen(氢), carbon(碳), nitrogen(氮), and oxygen atom. How could such complicated molecules have been formed in the primitive soup? Scientists were stumped(难住).
Then, in 1953, two scientists named Harold Urey and Stanley L. Miller did a very simple experiment to find out what had happened on the primitive Earth. They set up some tubes and bottles in a closed loop(线圈), and put in some of the same gases that were present in the atmosphere four billion years ago: water vapor, carbon dioxide(二氧化碳), methane(甲烷), and hydrogen.
Then they shot an electric spark through the gases to simulate(模拟)bolts(闪电)of lightning on the ancient Earth, circulated the gases through some water, sent them back for more sparks, and so on. After seven days, the water that the gases had been bubbling(起跑)through had turned brown. Some new chemicals were dissolved in it . When Miller and Urey analyzed the liquid, they found that it contained amino acids—the very kind of molecules found in all living things.
Scientists figured out that human bodies are basically made of______.
选项
A、amino acids
B、hydrogen, carbon, nitrogen and oxygen atoms
C、molecules
D、water vapor, ammonia, carbon dioxide, methane and hydrogen
答案
A
解析
文章第二段第一句:…scientists figured out that living things,including human bodies,are basically made of amino acids and nucleotide bases,科学家断定包括人在内的人物都是由氨基酸和核苷酸为基础构成的。
转载请注明原文地址:https://kaotiyun.com/show/wbxC777K
本试题收录于:
英语题库普高专升本分类
0
英语
普高专升本
相关试题推荐
Ifourself-examinationhasbroughtanycausesofstresstolight,letusconsiderwhatwecandoaboutthem.
A、Doctorandpatient.B、Passengerandticketcollector.C、Shopassistantandcustomer.D、Bossandclerk.D
A.Weshouldenhanceculturaldevelopmentandnotablypromotethecivilizationcharacterofthewholenation.B."Harmonygenera
Upto85percentofyoursusceptibility(敏感性)tomosquitobiteshasnothingtodowithwhatyou’redrinking,wearingorhowmuchhe
A.We’rewritingyouinordertoestablishbusinessrelationship.B.Thearrangementwillcontributetocementourpleasantrel
Fallsarethenumberonecauseofdeathtooldpeopleathome.Mostoldpeoplecanlivesafelyathomeiftheymakeafewchange
Therewassomuchnoisethatthespeakercouldn’tmakehimself______.
(74)AlotofrealbusinessesarefocusingontheInternetasawayofbuildingsales,butsomepeoplewithnothingtosellarec
Peter,whohadbeendrivingallday,suggested______atthenexttown.
Dadhadablackcomb.HeboughtitwhenhemarriedMum.Everynight,hewould【C1】______mehiscombandsay,"Goodgirl,helpDad
随机试题
计算
下列不属于物流成本的特性的是()
脊髓末端终止于()
A.牙间隙刷B.水平颤动法刷牙C.牙线D.牙签E.电动牙刷刷牙适合牙周患者者清除龈沟附近菌斑的方法是
"寸口脉动而弱,动则为惊,弱则为悸",此语出自何书
票据最原始、最简单的功能是()。
甲公司有关投资业务资料如下,假定各方盈余公积计提的比例均为10%,不考虑所得税影响。资料一:2015年7月1日,甲公司以银行存款15000万元从其他股东处购买了乙公司10%的股权。甲公司与乙公司的原股东在交易前不存在任何关联方关系,当日乙公司可辨认净资
【斯多噶派】(stoicism)
ManypeopleinvestinthestockmarkethopingtofindthenextMicrosoftandDell.However,Iknow【1】personalexperiencehowdif
原型化方法的基本思想是通过“试用—反馈—______”的多次反复,最终开发出真正符合用户需要的应用系统。
最新回复
(
0
)