Every electronic gadget (小玩意) needs good memory. A music player stores songs, albums and playlists. A puter holds schoolwork and programs and remembers how far a player has advanced in his or her favorite game. Mobile phones store names, numbers and hundreds of texts.
Now, scientists in California say they have e up with a way to turn a living cell into a memory device.
It can store only one tiny bit of information, but it’s a start. In the future, a cell-based gadget might travel through the body and record measurements. The benefit to human health could be big: the right tool, for example, might record the earliest signs of disease.
Doctors, scientists and other curious people want to know what is happening inside the body, even at levels that can’t be seen by the naked eye. So far, there is no device small enough to travel through the bloodstream.
If normal machines won’t do the trick, perhaps biology will. Scientists who work in the field of synthetic (合成的) biology are trying to find ways to turn living things into human tools. In the case of the new memory device, bioengineers from Stanford University used the genetic material inside living cells to record information.
This genetic material consists of DNA. Found in nearly every cell, DNA carries all of the information that keeps a living thing alive.
In the new experiment, the researchers turned DNA from bacteria(细菌) into a switch. They “flip (翻转)” a small section of DNA. Then, using the same procedure (过程) , the scientists flip the section again—returning it into its normal structure.
Using these DNA switches, “We can write and erase DNA in a living cell,” bioengineer, Jerome Bonnet, explained to Science News.
It might take years before his team or others identity whether a DNA-based memory device might be practical. Right now, it takes one hour to plete a flip. That is far too long to be useful. Plus, a flipped section has a very small little memory—less than what a puter uses to remember a single letter.
“This was an important proof that it was doable,” Bonnet told Science News. “Now we want to build a more plex system, something that other people can use.”
【小题1】What is the aim of listing the electronic things in the first paragraph?A．To make the passage more fashionable.B．To show how electronic things have memory.C．To discuss things in detail.D．To make the subject of the text more understandable.【小题2】What is possible future benefit of the cell-based gadget for people? A．To detect disease at the earliest point.B．To help improve the memory.C．To help people build a body.D．To replace many electronic gadgets.【小题3】What is the object being researched?
A. The cells of bacteria.
B. The DNA of bacteria.
C. A section of bacteria.
C. The nucleus of bacteria.
【小题4】What do we know about a flipped section of DNA?A．It has a very small memoryB．It can function as a puter. C．It has one letter in it. D．It takes a day to plete it.D
网友回答
(答案→)D
解析：本文主要介绍了科学家已经成功把活细胞植入了记忆装置以及现在科学家正在研究细菌的DNA。
【小题1】推断题。第一自然段列举电子事物的目的是使得这篇文章的主题更容易理解，故选D。
【小题2】 细节题。根据It can store only one tiny bit of information, but it’s a start. In the future, a cell-based gadget might travel through the body and record measurements. The benefit to human health could be big: the right tool, for example, might record the earliest signs of disease.可知它的好处在于可以早期发现疾病，故选A。
【小题3】细节题。根据In the new experiment, the researchers turned DNA from bacteria(细菌) into a switch. They “flip (翻转)” a small section of DNA. Then, using the same procedure (过程) , the scientists flip the section again—returning it into its normal structure.可知正在被研究的物体是细菌的DNA，故选B。
【小题4】 细节题。根据That is far too long to be useful. Plus, a flipped section has a very small little memory—less than what a puter uses to remember a single letter.故选A。