首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
What produces a waterproof super glue, acts like a vacuum cleaner, and even teaches scientists about gene repair? The humble lit
What produces a waterproof super glue, acts like a vacuum cleaner, and even teaches scientists about gene repair? The humble lit
admin
2005-07-06
82
问题
What produces a waterproof super glue, acts like a vacuum cleaner, and even teaches scientists about gene repair? The humble little shellfish known as the mussel (贻贝)。
Mussels are found worldwide. Some live in the sea. Others inhabit freshwater streams and lakes. When you try to move a mussel from a rock, you will discover what an incredibly firm grip it has a necessity if the mussel is to resist the sharp grab of a hungry seabird or the pounding waves of the sea. How does it manage to cling so tight? When it chooses a place to set up home, it pokes its tongue-shaped foot out of its shell and presses it against a solid surface. Special glands give off a fluid mixture of proteins into a channel that runs the length of the foot. The liquid quickly hardens into a fine, elastic thread about an inch long. Then a tiny pad-like structure at the end of this thread gives off some natural glue-like substance, the mussel lifts its foot, and anchor line number one is complete. These strategically placed threads form a bundle, which ties the mussel to its new home in much the same way that ropes hold down a tent. The whole procedure takes only three or four minutes.
Imagine having a very strong glue that is non-toxic and so flexible that it can penetrate the tiniest holes and corners, sticking to any surface, even under water. Shipbuilders would welcome it for repairing vessels without the expense of dry-docking them. Auto-body workers would like a really waterproof paint that keeps the rust out. Surgeons would value a safe glue to join broken bones and to close wounds... The list of possible uses appears endless.
However, scientists are not thinking of using the mussels themselves to produce this super glue. It would take some l0.000 shellfish to make just one gram of glue. So collection enough mussels to supply the world’s demand for super glue would wipe out the mussel population, many species of which are already endangered. Instead, American researchers have isolated and cloned the genes for five mussel glue proteins, and they are about to mass-produce them in the laboratory. However, the mussel is still one jump ahead. Only the mussel instinctively knows the exact blend of proteins needed for each kind of surface. Molecular biologist Frank Roberto has asked admiringly: "How are you ever going to imitate that?"
选项
A、seal itself from being damaged by sea water
B、protect itself from being the food of other animals
C、protect itself from being blown away by strong wind
D、produce the waterproof super glue
答案
B
解析
第二段第三句提到,贻贝抓紧岩石主要是为了避免被海鸟抓走或海浪带走。
转载请注明原文地址:https://kaotiyun.com/show/wxmi777K
0
在职申硕(同等学力)英语
相关试题推荐
腰椎间盘突出症所致典型下肢痛位于
Thefactthattheearth’ssurfaceheats______providesaconvenientwaytodivideitintotemperatureregions.
Someinternationalstudents(use)acassetterecorder(tomake)tapesoftheirclasses(sothat)theycanrepeatthelectures(a
TheElNinohas______affectedtheregionalweatherandtemperatureovermuchofthetropics,sub-tropicsandsomemid-latitude
ShouldEnglishclassesbecompulsoryattheelementaryorprimaryschoollevelincountrieswhereitisnotthenativelangue?
Factorsleadingtothecrisisincludedpoorregulation,mismanagementanddeceptionintheindustry,andcompetitionfromother
(Unable)toseetheirbusinessasaseparateentity,manypeoplefailtomake(a)distinction(between)theircompanyand(them)
Whatismostremarkableabouttheproposalmadebythetwoscientists?Whichofthefollowingcanbestdescribetheattitudeof
Fordecades,researchershavegrappledwiththeproblemofcreatingamachinethatcantell,definitively,whetherapersonisl
随机试题
金融远期合约主要包括()。Ⅰ.远期货币期货Ⅱ.远期利率协议Ⅲ.远期外汇合约Ⅳ.远期股票合约
TheKiltWheneverpeoplefromScotlandliveinforeigncountries,theyarealwaysasked:“IsScotlandthatplacewheremenw
决定病变虚实的病机是
索赔意向通知包括的主要工作有()。
高级会计资格的取得实行()。
会计制度包括对会计工作、会计核算、会计监督、会计人员、会计档案等方面的规范性文件。()
党的十八届五中全会指出,我国仍处于并将长期处于社会主义初级阶段,基本国情和社会主要矛盾没有变,这是谋划发展的基本依据,必须坚持以经济建设为中心,从实际出发,把握发展新特征,加大结构性改革力度,加快转变经济发展方式,实现更高质量、更有效率、更加公平、更可持续
怀特认为,教育应该增进受教育者的幸福感,这种观点可能比教育应该以追求知识本身为目的的观点更有市场。大多数人认为,教育应主要考虑学生的利益。你怎样看待这一观点?这种观点对基础教育改革有什么意义?
AThoughmanydistinctculturesareprevalentaroundtheworldtoday,thosethatarethemostdominanthaveoriginsinoneofa
VisualFoxPro应用程序在显示初始界面后需要建立一个事件循环来等待用户的操作,控制事件循环的命令是
最新回复
(
0
)