共用题干 第一篇Can Gene Technology Make Human Smarter?Almost everyone wants to get smarter. To achieve that...
第一篇
Can Gene Technology Make Human Smarter?
Almost everyone wants to get smarter. To achieve that,some choose to do exercise,others choose to take in more nutritions good for brains.Princeton neurobiologist Joseph Z.Tsien possibly found a different way to make it. In September he announced that he'd built a better mouse by altering a gene that affects learning and memory.A similar process of gene manipulation might conceivably be used one day to boost intelligence in humans.
The key of this technology lies in a feature of brain cells called the NMDA receptor,which Tsien likens to a cylindrical tube or window that mediates the flow of information.When the window is open,chemicals called neurotransmitters flow through easily and memory is registered and stored. But as organisms mature,the window begins to close.(This may explain why children lose their facility for learning new languages when they reach sexual maturity and why some people suffer memory loss as they age.)
Tsien also found out that the receptor worked more efficiently if it is teamed with the gene NR2B,so he introduced extra NR2B genes into a batch of fertilized mouse eggs.In a normal mouse,the memory window is open for just 150-thousandths of a second.In Tsien's specially engineered mice,the window opens for 250-thousandths of a second,long enough to make a remarkable difference in memory retention.When he pitted his mice against common mice,they won paws down.Ordinary mice could recognize a Lego block for 12 hours,but smart mice could remember the block for up to three days."That's a profound enhancement,"Tsien says.
Can this technology be applied to humans?Maybe,but genetic engineering will have to make some extraordinary advances first. And some thorny ethical issues will have to be resolved. Mean-while,Tsien promises to keep his furry little geniuses locked up in a lab,far from your larder. "Otherwise,"he says,"you might need a smart cat or a smart mousetrap to catch them."
参考答案: B
参考解析: 本题是细节考查题。题干是：根据这篇文章，Tsien发现的培养更聪明老鼠的特另，l方法是什么？ 第一段第四句提到："In September he announced that he'd built a better mouse by altering a gene that affects learning and memory.”他于9月宣布，通过改变影响学习和记忆能力的基因培养出了一只聪明的老鼠。选项B，通过改动能影响学习和记忆的基因的方法，与原文意思相符，所以选B。
本题是细节考查题。题干是：这项技术最重要的部分是______。在原文第二段第一句提到："The key of this technology lies in a feature of brain cells called the NMDA receptor”该技术的关健就在于名为N-甲基-D-天冬氨酸受体的脑细胞的特点。选项D，名为 N-甲基-D-天冬氨酸受体的脑细胞的特点，与原文意思相符，所以选D。
本题是细节考查题。题干是：为什么一些老人容易失忆？选A的依据是第二段的最后两句："But as organisms mature, the window begins to close.This may explain...why some people suffer memory loss as they age.”然而，当器官成熟时，这扇窗口就开始关闭。这也能解释……为何某些人年老时会患失忆。选项A，当人的器官成熟，记忆之窗就很可能关闭。
本题是细节推理题。题干是：当Tsien提到“这可是一个意义深远的进步”时，所指的是什么？ 选择A的依据是第三段的第四和第五句："When he pitted his mice against common mice,they won paws down .Ordinary mice could recognize a Lego block for 12 hours, but smart mice could remember the block for up to three days.”当他让自己的老鼠与普通老鼠互斗时，它们竟能轻而易举地取胜。普通老鼠能够保留关于Lego block的记忆12小时，而聪明的老鼠居然能将记忆保持三天。选项A，他的聪明老鼠比普通老鼠记忆时间更长，概括说明了信息句的意思，所以选A。
本题考查概括能力。题干是：在这项技术应于人类之前，必须解决哪些问题？选B的依据是全文最后一段的第二、三句："Maybe, but genetic engineering will have to make some extraordinary advances first.And some thorny ethical issues will have to be resolved." 或许可以，但前提是基因工程得首先做出非凡的进步，还必须解决一系列棘手的伦理问题。所以选项B，基因工程做出非凡进步，一系列棘手的伦理问题得以解决，是正确答案。
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