Question

    Researchers around the world interested in uncovering complex human disorders, such as Alzheimer’s disease, could soon have access to cloned monkeys with genomes that have been edited to display these conditions in China.

On 24 January, scientists at the Institute of Neuroscience (ION) in Shanghai reported that they had used gene-editing to disable a gene in monkeys that is crucial to their sleep- wake cycle. The scientists then cloned one of those monkeys to produce five primates (灵 长目动物)with almost identical (相同的) genes. It is the first time that researchers have cloned a gene-edited monkey.

Primates are the best animal model for studying higher cognitive (认知的)functions and brain disorders in humans, says neuroscientist Mu-ming Poo, ION’S director and co-founder of the new 720 million yuan (US$106 million) centre. The advantage of creating cloned monkeys is that it reduces the number of animals needed for certain types of experiments, such as testing whether a drug works.

But some scientists think that experiments using monkeys should be a last approach because of their higher levels of cognition. Mitchell Lazar, who studies metabolic disease at the University of Pennsylvania, says that some experiments in mice—for example, research into the genes behind human diseases—are equally appropriate scientifically as in primates. Research in mice is also more accepted by the public, and the animals are cheaper and quicker to produce. Lazar worries that if scientists have ready access to populations of gene-edited monkeys, they might use them for experiments when rodents (啮齿动物)would do.

Poo says that mice are not a good substitute for studying higher cognitive functions and brain disorders in humans. He argues that cloning will reduce the burden on monkeys by cutting the number used in labs. The ION follows strict international guidelines for animal research, he says.

Poo’s team will continue to study the effect of gene editing on their five cloned monkeys. The group disabled a gene, BMAL1, that has a crucial role in maintaining circadian rhythm (生理节奏)，the internal clock that helps a healthy sleep-wake cycle. In people, BMAL1 mutations have been linked to diabetes, hypertension and depression.

The monkeys with the disabled BMAL1 genes move more at night and sleep less overall. They also display psychosis-related symptoms, such as fear and anxiety, when put in unfamiliar environments.

The team ’ s next step is to look in detail at the neural (神经的)mechanisms that might create these problems. It will also take advantage of the genetically identical monkeys to hunt for diagnostic markers of circadian rhythm-related disorders and possible treatments.

1.Why were the genetically identical monkeys cloned?

A. To prove scientists’ innovation in cloning animals.

B. To study the rare characteristics of cloned monkeys.

C. To explore many possibilities for monkeys’ cognition.

D. To provide improved animal models of human diseases.

2.What does Mitchell Lazar think of cloning monkeys?

A. It is of little value.

B. It is of much practice.

C. It is hardly acceptable.

D. It is completely illegal.

3.From the passage we can know that Poo’s team will .

A. continue to disable a gene on the monkeys

B. try to clone more monkeys and edit their genes

C. find the similarities between humans and monkeys

D. determine the cause of sleep disorders and find cures

4.What’s the main idea of the passage?

A. Chinese effort to clone gene-edited monkeys kicks off.

B. Chinese dream to clone monkeys has finally come true.

C. Cloning monkeys is an important breakthrough in science.

D. Cloning gene-edited monkeys has caused some moral risks.

Answer

1.D

2.C

3.D

4.A

【解析】

本文是一篇科普说明文。文章讲述中国开始克隆基因编辑的猴子。

1.推理判断题。本题通过阅读第一段和第二段可以知道答案，第一段中human disorders… could have access..和第二段都表达了人们想通过研究cloned monkey 来解决人类的disorder。故选D。

2.推理判断题。本题答案在文章第四段，第一句some scientists think that…higher levels of cognition. MitchellLazar…这里提到了题干中的人名，他说到老鼠起到的效果和灵长类是一样的，而且更容易被大众接受。故选C。

3.推理判断题。第六段说了他会继续在物质克隆猴子上做实验，但是没说会不会克隆更多，所以可以排除AB。倒数第一段说到了Poo 团队的下一步是发现神经机制可能产生的问题，和possible treatments和D项是同义替换。故选D。

4.主旨大意题。B/C显然不是文章要表达的意思可以排除。D选项说到用猴子做实验引起了一些道德风险，这是文章中提到的，但并不是main idea，因此排除。文章是围绕开始的基因改变克隆而写的。故选A。