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
We tend to think of plants as the furniture of the natural world. They don’t move, they don’t make sounds, they don’t seem to re
We tend to think of plants as the furniture of the natural world. They don’t move, they don’t make sounds, they don’t seem to re
admin
2015-11-11
44
问题
We tend to think of plants as the furniture of the natural world. They don’t move, they don’t make sounds, they don’t seem to respond to nothing—at least not very quickly. But as is often the case, our human view of the world misses quite a lot. Plants talk to each other all the time. And the language is chemical.
Over the years, scientists have reported that different types of plants, from trees to tomatoes, release compounds into the air to help neighboring plants. These chemical warnings all have the same purpose—to spread information about one plant’s disease so other plants can defend themselves. But exactly how plants receive and act on many of these signals is still mysterious.
In this week’s Proceedings of the National Academy of Sciences, researchers in Japan offer some explanations. They have identified one chemical message and traced it all the way from release to action.
The scientists looked at tomato plants infested(侵害)by common pest, the cutworm caterpillar(毛虫). To start out, they grew plants in two plastic compartments connected by a tube. One plant was infested and placed upwind and the others were uninfested and placed downwind. The downwind plants were later exposed to the cutworm caterpillar. The results showed that plants that had previously been near sick neighbors were able to defend themselves better against the caterpillar.
The researchers also studied leaves from exposed and unexposed plants. They found one compound showed up more often in the exposed plants. The substance is called HexVic. When the scientists fed HexVic to cutworms, it knocked down their survival rate by 17%. The scientists identified the source of Hex Vic, and sprayed it lightly over healthy plants. Those plants were then able to start producing the caterpillar-killing Hex Vic. Researchers confirmed that uninfested plants have to build their own weapon to fight off bugs and diseases. How do they know when to play defense? They are warned first by their friendly plant neighbors.
It is a complex tale, and it may be happening in more plant species than tomatoes. It may also be happening with more chemical signals that are still unknown to us. For now though, we know that plants not only communicate, they look out for one another.
The experiment shows that the infested plant helps its neighbors by______.
选项
A、making more HexVic to attract the pest
B、releasing HexVic into the air to warn them
C、letting them know how to produce HexVic
D、producing enough HexVic to kill the pest
答案
D
解析
细节题。定位到倒数第二段,暴露在pest之下的植物更多地产生了一种叫HexVic的化学物质,这种化学物质会使得害虫的存活率下降17%。因此本题的最佳答案为D。
转载请注明原文地址:https://kaotiyun.com/show/lwQi777K
0
在职申硕(同等学力)英语
相关试题推荐
Learningdisabilitiesareverycommon.Theyaffectperhaps10percentofallchildren.Fourtimesasmanyboysasgirlshavelea
Aninternationaltreatysignedseveralyearsagobanstradeinplantsandanimalofendangeredspecies.
AfricanAmericanwomen’ssearchforsocietalacceptanceoftenencompassesstrugglebetweennaturalandsociallyconstructedidea
AfricanAmericanwomen’ssearchforsocietalacceptanceoftenencompassesstrugglebetweennaturalandsociallyconstructedidea
AfricanAmericanwomen’ssearchforsocietalacceptanceoftenencompassesstrugglebetweennaturalandsociallyconstructedidea
AfricanAmericanwomen’ssearchforsocietalacceptanceoftenencompassesstrugglebetweennaturalandsociallyconstructedidea
Thebadanddampweatherinthehotareawouldenabletheplantstoget_____quickly.
随机试题
中国公民同外国人在中国内地自愿离婚的()
临床上局麻时在麻药中加入,肾上腺素的作用如下,其中哪项可以除外
滑石粉
有效边界上的点对应的证券组合称为有效组合。()
根据《刑法》规定,下列有关逃税罪的表述中错误的是()。
当企业拥有反诉或向第三方索赔的权利而涉及补偿金额时,该补偿金额单独作为一项资产确认的条件之一是()。
根据《导游人员管理条例》规定,对下列()人员不得颁发导游证。
工作中你难以和同事、上司相处,你该怎么办?
TheHeadlandHypothesisarguesthatforagingornon-agriculturaltribeshavebeenunabletocollectadequatecarbohydrate
Bicyclesharinghasbeenahotlydebatedtopicoverthepasttwoyears.BicyclesarenothingexotictoChinesepeople.Inthe19
最新回复
(
0
)