首页
登录
职称英语
For many years, scientists couldn’t figure out how atoms and molecules combi
For many years, scientists couldn’t figure out how atoms and molecules combi
游客
2024-07-08
7
管理
问题
For many years, scientists couldn’t figure out how atoms and molecules combined to make living things. Plants, fish, dinosaurs, 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 have energy and can reproduce, while the chemicals on the Earth 4 billion years ago were lifeless.
After years of study, scientists figured out that living things, including human bodies, are basically made of amino acids, nucleotide bases, lipids and water. How could such complicated molecules have been formed and have started to interact in the primitive soup? Scientists were stumped.
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, and put in some of the same gases that were present in the atmosphere 4 billion years ago—water vapour, ammonia, carbon dioxide, methane, and hydrogen.
Then they shot an electric spark through the gases to simulate bolts of lightning on the ancient Earth, circulated the gases through some water, sent them back for more sparks, and so on. After several days, the water that the gases had been bubbling through 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.
选项
A、4 billion years ago.
B、After seven days.
C、Many years ago.
D、In 1953.
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3667718.html
相关试题推荐
_______enoughtime,butIcouldn’tdoitbetter.A、IwasgivenB、GivenC、Tobeg
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
[originaltext]M:Theadvertisementsonthesubwaysareboring.W:Icouldn’tag
Ifyoucouldn’tkeepthe(appoint)________,pleaseinformusasearlyaspossib
(watch)______byacrowdofpeople,Charlesfeltembarrassedandcouldn’tsay
随机试题
血管造影时引入对比剂的方法属于A.口服法 B.灌注法 C.直接引入法 D.
2020年度某企业通过市政府向灾区捐款100万元,直接向受灾小学捐款20万元,两
患者35周妊娠,食欲不振,伴恶心呕吐一周。查体:T:36.6℃,P:96次/分
协定账户属于非存款性负债业务创新。()
定金合同是当事人双方为了保证债务的履行,按照合同规定向对方预先给付一定数额的货币
下列属于传染性非典型肺炎糖皮质激素治疗指征的是A:有严重中毒症状,经对症治疗高热
Thechangeinthatvillagewasmiraculou
在下列权益中,不属于《妇女权益保障法》明确规定的妇女依法享有的权益是()。A:婚
从网络购买的以下商品,消费者有权自收到商品7日内退货的是( )。A.订做的西服
在下列太阳系行星中,距太阳最近的是()。 A.水星B.地球C.火星D.
最新回复
(
0
)