logo - 刷刷题
下载APP
【单选题】

Passage Five
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 choose a place to set up home, it pokes its tongue-shaped foot out of its shell and presses it against a solid suce. 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 suce, 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 enered. 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 suce. Molecular biologist Frank Roberto has asked admiringly: "How are you ever going to imitate that"
The waterproof super glue originates in ______

A.
the mussel’s tongue-shaped foot
B.
the channel of the mussel’s foot
C.
the thread given off by the mussel
D.
some glands in the mussel’s body
题目标签:贻贝
举报
参考答案:
参考解析:
.
刷刷题刷刷变学霸
举一反三

【单选题】贻贝的出产旺季为()。

A.
1~4月
B.
5~9月
C.
6~10月
D.
10~12月

【单选题】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...

A.
seal itself from being eroded by sea water
B.
produce the waterproof super glue
C.
protect itself from being blown away by strong wind
D.
protect itself from being the food of other animals

【单选题】贻贝隶属于双壳类,其发育经历了变态期,属于其经历时期的是()

A.
担轮幼虫和面盘幼虫
B.
面盘幼虫和钩介幼虫
C.
担轮幼虫和钩介幼虫
D.
上述均不是