2. 职称英语
  3. A new type of organism discovered in an Arctic tunnel came to life in the l

A new type of organism discovered in an Arctic tunnel came to life in the l

游客2023-11-07  31
问题      A new type of organism discovered in an Arctic tunnel came to life in the lab after being frozen for 32,000 years. The deep-freeze bacteria could point to new methods of cryogenics, and they are the sort of biology scientists say might exist on Mars and other planets and moons. "The existence of microorganisms in these harsh environments suggests——but does not promise——that we might one day discover similar life forms in the glaciers or permafrost of Mars or in the ice crust and oceans of Jupiter’s moon Europa," said Richard Hoover, an astrobiologist at NASA’s Marshall Space Flight Center. Other microbes have been discovered in similar frigid environments, sometimes clinging to pockets of liquid water in ice packs. And some microbes survive in ice as spores, but they need to be cultured to bring them to life.
     The announcement of the discovery Wednesday comes just a day after a team of European re- searchers said they found blocks of ice just under the surface of Mars near the equator. The Europeans said the ice, between 2 million and 5 million years old, could serve as storehouses for life. The new bacterium thrives under a microscope despite having been thawed from ice dating back some 32,000 years, to the Pleistocene era. Living bacteria are stained green.
     Hoover said the creatures he has found might be able to survive in their suspended state for millions of years. The discovery opens up a whole new possibility that a future mission to Mars might be able to retrieve any life that’s there. "Ice samples from this [Martian ice] sea could con-rain cryopreserved microorganisms if life ever flourished on the surface of Mars," Hoover said in a telephone interview. He is particularly excited about the instant revival qualities of the creatures found in Alaska. "You might actually get them growing in pure culture," he said of the potential Martian cousins. It would be a "wonderful way of retrieving intact, viable Martian organisms, if they are there."
     Water does not guarantee life, but it is a crucial ingredient. Hoover said the Martian ice blocks are so near the surface that they might partly melt in summer, creating underground pools of water that would allow any microorganisms to grow and reproduce. (Life above ground is considered unlikely due to Mars’ dry surface conditions and intense radiation. ) [br] In the third paragraph, the word "flourish" in line four probably means _________.
选项 A、to grow and thrive
B、to make showy motions
C、to pour out
D、to strike noisily.
答案 A
解析 词汇题。文章第三段中“Ice samples from this [Martian ice] sea could contain cryopreserved microorganisms if life ever flourished on the surface of Mars，”这句话中的意思是：如果火星表面的确有生命迹象存在过，那么从火星上的海水中得到的冰标本就有可能存有低温保存的微生物)。flourish的意思是“grow and thrive”(生长、繁荣)，选项B“卖弄的动作”、选项C“倾诉”
转载请注明原文地址:https://tihaiku.com/zcyy/3166336.html
相关试题推荐
随机试题
最新回复(0)