人教版（新课程标准） 选修8 Unit 2 Cloning习题含解析（4份打包）.zip

Unit 2 Cloning
Ⅰ.阅读理解
Have you seen Jurassic Park? In this film, scientists use DNA kept for tens of millions of years to clone dinosaurs. They find trouble，however，when they realize that the cloned creatures are smarter and more dangerous than expected. That's nothing more than a fiction.
But could we really clone endangered animals?
To date, the most successful attempt to do so was the cloning of a gaur，a rare ox­like animal from southeast Asia. Scientists used a cow to bring the cloned baby gaur, named Noah. Two days after birth，however，Noah died from a common bacterial infection.Other endangered species that may be cloned include the African bongo antelope(羚羊), the Sumatran tiger, the cheetah(猎豹), and the giant panda.
Next，could we really clone extinct animals?
In theory？Yes.To do this, you need a well­kept source of DNA from the extinct animals such as wool mammoth(毛象)，Tasmanian tiger，or even dinosaur, and a closely related species, still living，which could serve as a_surrogate_mother.
In reality? Probably not. On the one hand, it's not likely that extinct animals' DNA could survive undamaged for such a long time. Cloning such extinct animals as wool mammoth, Tasmanian tiger，or dinosaur is much more difficult due to the lack of properly well­preserved DNA. On the other hand, for example, a gaur can have a cow as a surrogate mother, definitely not a monkey.