[不定项选择题]共用题干 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." What problems must be solves before this technology is applied to human? A:Gene must be conceivably manipulated.
A.Genetic engineering will have to make some extraordinary advances first and some thorny ethical issues will have to be resolved.
B.NMDA receptor is teamed with the gene NR2
C.
D.The smart nice must be locked up in a lab.

[不定项选择题]共用题干 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." What problems must be solves before this technology is applied to human? A:Gene must be conceivably manipulated.
A.Genetic engineering will have to make some extraordinary advances first and some thorny ethical issues will have to be resolved.
B.NMDA receptor is teamed with the gene NR2
C.
D.The smart nice must be locked up in a lab.

[不定项选择题]共用题干 第一篇

Human Heart can Make New Cells

Solving a longstanding（为时甚久的）mystery, scientists have found that the human heart continues to
generate new cardiac（心脏的）cells throughout the life span, although the rate of new cell production slows
with age.
The finding,published in the April 3rd issue of Science,could open a new path for the treatment of heart
diseases such as heart failure and heart attack,experts say.
"We find that the beating cells in the heart, cardiomyocytes（心肌细胞）,are renewed," said lead
researcher Dr. Jonas Frisen,a professor of stem cell research at the Karolinska Institute in Stockholm,
Sweden."It has previously not been known whether we were limited to the cardiomyocytes we were born with
or whether they could be renewed,"he said.
"The process of renewing these cells changes over time,"Frisen added. In a 20-year-old,about 1
percent of cardiomyocytes are exchanged each year , but the turnover（更替）rate decreases with age to only
0.45 percent by age 75.
"If we can understand how the generation of new cardiomyocytes is regulated,it may be potentially
possible to develop pharmaceuticals（药物）that promote this process to stimulate regeneration after , for
example,a heart attack,"Frisen said.
That could lead to treatment that helps restore damaged hearts.
"A lot of people suffer from chronic heart failure,."noted co-author Dr. Ratan Bhardwaj,also from the
Karolinska Institute."Chronic heart failure arises from heart cells dying," he said.
"With this finding,scientists are opening the door to potential therapies（疗法）,to having ourselves heal
ourselves,"Bhardwaj said."Maybe one could devise a pharmaceutical agent that would make heart cells
make new and more cells to overcome the problem they are facing."
But barriers remain.According to Bhardwaj,scientists do not yet know how to increase heart cell
production to a rate that would replace cells faster than they are dying off,especially in older patients with
heart failure.In addition,the number of new cells the heart produces was estimated using healthy hearts一
whether the rate of cell turnover in diseased hearts is the same remains unknown. It is not known yet if the rate of cell turnover in diseased hearts_________.
A.is high enough to replace cells faster than they're dying off
B.is of any use to researchers
C.is the same as that in healthy hearts
D.changes over time

[不定项选择题]共用题干 第一篇

Can Buildings Be Designed to Resist Terrorist Attack?

In the aftermath of the terrorist attack on the World Trade Center,structural engineers are trying hard to
solve a question that a month ago would have been completely unthinkable:Can buildings be designed to
withstand catastrophic blasts inflicted by terrorists?
Ten days after the terrorist attacks on the twin towers,structural engineers from the University at Buffalo
and the Multidisciplinary Center for Earthquake Engineering Research(MCEER)headquartered at UB
traveled to ground zero as part of a project funded by the National Science Foundation.Visiting the site as
part of an MCEER reconnaissance visit,they spent two days beginning the task of formulating ideas about
how to design such structures arid to search for clues on how to do so in buildings that were damaged but still
are standing.
"Our objective in visiting ground zero was to go and look at the buildings surrounding the World Trade
Center,those buildings that are still standing,but that sustained damage,"said M.Bruneau,Ph. D."Our im-
mediate hope is that we can develop a better understanding as to why those buildings remain standing,while
our long-term goal is to see whether earthquake engineering technologies can be married to existing technolo-
gies to achieve enhanced performance of buildings in the event of terrorist attacks,"he added.
Photographs taken by the investigators demonstrate in startling detail the monumental damage inflicteed
on the World Trade Center towers and buildings in the vicinity.One building a block away from the towers
remains standing,but was badly damaged."This building is many meters away from the World Trade Center
and yet we see a column there that used to be part of that building,"explained A.Whittaker,Ph. D."The
column became a missile that shot across the road,through the window arid through the floor."
The visit to the area also revealed some surprises,according to the engineers.For example,the floor
framing system in one of the adjacent buildings was quite rugged,allowing floors that were pierced by tons of
falling debris to remain intact. " Highly redundant ductile（有延展性的）framing systems may provide a sim-
pie,but robust strategy for blast resistance,"he added.Other strategies may include providing alternate paths
for gravity loads in the event that a load一bearing column fails."We also need a better understanding of the
mechanism of collapse,"said A.Whittaker."We need to find out what causes a building to collapse and how
you can predict it."
A.Reinhorn,Ph. D.noted that"Earthquake shaking has led to the collapse of many buildings in the
past.It induces dynamic response and extremely high stresses and deformations in structural components.So-
lutions developed for earthquake-resistant design may be directly applicable to blast engineering and
terrorist-resistant design.Part of our mission now at UB is to transfer these solutions and to develop new ones
where none exist at present." What Dr. Reinhorn said in the last paragraph may imply all the following EXCEFT that ________.
A.blast engineers should develop new solutions for terrorist-resistant design
B.blast engineering can borrow technologies developed for terrorist-resistant design
C.solutions developed for earthquake-resistant design may apply to terrorist-resistant design
D.blast engineering emerges as a new branch of science