Question

    Chinese scientists recently have produced two monkeys with the same gene, Zhong Zhong and Hua Hua, using the same technique that gave us Dolly the sheep. These monkeys are not actually the first primates(灵长类)to be cloned. Another one named Tetra was produced in the late 1990s by embryo(胚胎)splitting, the division of an early-stage embryo into two or four separate cells to make clones. By contrast, they were each made by replacing an egg cell nucleus(卵原子核)with DNA from a differentiated body cell. This Dolly method, known as somatic(躯体的) cell nuclear transfer(SCNT), can create more clones and allows researchers greater control over the edits they make to the DNA.

Success came from adopting several new techniques. These included a new type of microscopy(显微术) to better view the cells during handling or using several materials that encourage cell reprogramming, which hadn’t been tried before on primates. Still, the research process proved difficult, and many attempts by the team failed. Just two healthy baby monkeys born from more than 60 tested mothers. This leads to many researchers’ pouring water on the idea that the team’s results bring scientists closer to cloning humans. They thought this work is not a stepping stone to establishing methods for obtaining live born human clones. Instead, this clearly remains a very foolish thing to attempt, and it would be far too inefficient, far too unsafe, and it is also pointless.

But the scientists involved emphasize that this is not their goal. There is now no barrier for cloning primate species, thus cloning humans is closer to reality. However, their research purpose is entirely for producing non-human primate models for human diseases; they absolutely have no intention, and society will not permit this work to be extended to humans. Despite limitations, they treat this breakthrough as a novel model system for scientists studying human biology and disease.

1.What do we know about the technology called SCNT?

A. It created the first primates.

B. It may contribute to editing the DNA.

C. It can divide an early-stage embryo into several cells.

D. It produced two cloned monkeys with different genes.

2.What does the author mean by “pouring water on the idea” in paragraph 2?

A. Keeping a hot topic of it. B. Paying no attention to it.

C. Having a low opinion of it. D. Adding supportive evidence to it.

3.What is the scientists’ purpose to clone these monkeys?

A. To prepare for their research on human cloning.

B. To serve as a stepping stone to their reputation.

C. To help with the study of human diseases.

D. To clone other animals for scientific use.

4.What can we infer from the passage?

A. Cloning humans is already on its way.

B. New techniques seem to be pointless.

C. Society won’t agree to clone another monkey.

D. The success rate of this cloning of monkey was not high.

Answer

1.B

2.C

3.C

4.D

【解析】

这是一篇说明文。最近，中国科学家用制造多利羊的技术生产了两只基因相同的猴子。这种被称之为SCNT的方法可以使研究人员能够更好地控制他们对DNA的编辑。科学家们克隆这些猴子的目的是为了更好的研究人类疾病。

1.细节理解题。根据第一段中的“This Dolly method, known as somatic(躯体的) cell nuclear transfer(SCNT), can create more clones and allows researchers greater control over the edits they make to the DNA.”可知，这种被称为SCNT的方法可以创造更多的克隆，并使研究人员能够更好地控制他们对DNA的编辑。由此可知，SCNT有助于DNA的编辑。故B选项正确。

2.词义猜测题。画线部分前文提到：研究过程被证明是困难的，而且小组的许多尝试都失败了。60多名接受测试的母猴子只生了两只健康的小猴子。这导致许多研究人员认为，该小组的研究结果使科学家更接近于克隆人类。画线部分后文提到：研究人员认为这项工作是一个非常愚蠢的尝试，它效率太低，太不安全，毫无意义。由此可以推知，研究人员认为，这个团队的研究结果并没有使克隆人更进一步。结合选项可知，研究人员对这个研究结果评价不高，故C选项正确。

3.推理判断题。根据最后一段中的“However, their research purpose is entirely for producing non-human primate models for human diseases; they absolutely have no intention, and society will not permit this work to be extended to humans.”可知，他们的研究目的完全是为了制造针对人类疾病的非人类灵长类动物模型。由此可以推知，他们这么做是为了研究人类疾病。故C选项正确。

4.推理判断题。根据倒数第二段中的“Still, the research process proved difficult, and many attempts by the team failed. Just two healthy baby monkeys born from more than 60 tested mothers.”可知，研究过程被证明是困难的，而且小组的许多尝试都失败了。60多名接受测试的母亲只生了两只健康的小猴子。由此可知，克隆猴子的成功率并不高。故D选项正确。