首页
登录
职称英语
[originaltext] Today, we are going to talk about a special way some plants r
[originaltext] Today, we are going to talk about a special way some plants r
游客
2025-02-09
30
管理
问题
Today, we are going to talk about a special way some plants respond to being invaded by pests. The plants react by emitting a chemical signal, which acts like a call for help. Let’s take corn plants for example. Sometimes, caterpillars chew on the corn leaves. When the caterpillar saliva mixes with the chew portion of a leave, the plant releases a chemical scream that attracts wasps. The wasps respond to the signal by flying to the chewed on leave, and laying their eggs on the caterpillars. The caterpillars die in the next few days as the wasp offspring nourish themselves by feeding of them. Thus the corn plant prevents all its leaves from being eaten by the caterpillars. This chemical scream is specific. It’s only released after the plant has detected the caterpillar saliva. A plant that is cut by in the other means does not give off the same signal, nor doesn’t undamaged plants. This also explains how a wasp can find a caterpillar in a huge field of corn. Soybean, cotton and probably many other plants use similar type of defense against pests. By enhancing this natural response in plants, researchers might reduce, some day even eliminate, the need for chemical pesticide, which can cause ecological damage. For example, scientists might breed plants for this screaming trait, or they might transplant specific genes to increase the release of the chemical signals.
选项
A、To describe ways pests can damage plants
B、To examine the life cycle of caterpillars
C、To explain how com plants develop
D、To describe how a natural pesticide works
答案
D
解析
What’s the main purpose of the talk?
转载请注明原文地址:https://www.tihaiku.com/zcyy/3949105.html
相关试题推荐
[originaltext]Today,wearegoingtocontinueourdiscussionofBuddhism.I
[originaltext]Today,wearegoingtocontinueourdiscussionofBuddhism.I
[originaltext]Today,wearegoingtotalkaboutaspecialwaysomeplantsr
[originaltext]Today,wearegoingtotalkaboutaspecialwaysomeplantsr
[originaltext]M:IamsorelievedIjustfinishedthestoryIwasworkingonfo
[originaltext]M:IamsorelievedIjustfinishedthestoryIwasworkingonfo
[originaltext]M:IamsorelievedIjustfinishedthestoryIwasworkingonfo
[originaltext]W:DrManning,doyouhaveafewminuets.I’dliketoaskyouabo
[originaltext]W:DrManning,doyouhaveafewminuets.I’dliketoaskyouabo
[originaltext]W:DrManning,doyouhaveafewminuets.I’dliketoaskyouabo
随机试题
WhenPh.D.candidates______theirimpendingprofessorships,theyconsiderhousin
He______the8:20busbecausehedidn’tleavehometill8:25.A、couldn’thaveca
Toseeifhaircoloraffectsaperson’schancesofgettingajob,researcher
[originaltext]W:Wellhithere.Whatareyoulookingfortoday?M:Uh,I’mjust
[originaltext]Today’slecturewillcenteronprehistoricpeopleoftheNeva
面部疖痈的主要病原菌是A.链球菌 B.金黄色或白色葡萄球菌 C.肺炎球菌
基金监管中,( )是经营活动的出发点和价值归宿。A.基金监管机构 B.基金监
关于补体的描述错误的是A.补体是存在于人和脊椎动物血清与组织液中一组经活化后有酶
下列关于审计取证基本方法的表述中,错误的是:A:顺查法是指从检查原始凭证入手的审
A.甲、乙组合 B.乙、丙组合 C.甲、丙组合 D.甲、乙、丙组合
最新回复
(
0
)