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
Perhaps the most familiar plant movement belongs to one species of mimosa called the sensitive plant. Within seconds, it can low
Perhaps the most familiar plant movement belongs to one species of mimosa called the sensitive plant. Within seconds, it can low
admin
2011-01-17
74
问题
Perhaps the most familiar plant movement belongs to one species of mimosa called the sensitive plant. Within seconds, it can lower its leaves and make its tiny leaflets close up like folding chairs. This movement is thought to be initiated by electrical impulses remarkably similar to nerve signals in animals. But without the animals’ sophisticated motion machinery, the mimosa has had to be creative in devising a way to move.
For motion, the plant depends on tiny, bulb-shaped organs located at the base of each leaf stalk and leaflet. Called pulvini, these organs hold the plant parts in place. When the mimosa is stimulated—say, by a crawling insect or a sudden change in temperature—an electrical impulse sweeps through the plant. This causes potassium and then water to be shifted from certain cells in the pulvini to others, quickly turning one side of the organs flaccid. Because the pulvini can no longer support the leaves and leaflets, this shift results in a corresponding change in their position.
The passage is mainly concerned with the ______.
选项
A、geographical distribution of plant and animal species
B、location and purpose of the pulvini
C、appearance of the mimosa
D、process that causes movement in the mimosa
答案
D
解析
本文讲述的是含羞草植物枝叶运动的过程。
转载请注明原文地址:https://www.kaotiyun.com/show/q0Yi777K
本试题收录于:
GCT工程硕士(英语)题库专业硕士分类
0
GCT工程硕士(英语)
专业硕士
相关试题推荐
法的指引作用的对象是()。
下列选项中,属于唐朝“六赃”犯罪的情形有()。
Ingeneral,theamountthatastudentspendsforhousingshouldbeheldtoone-fifthofthetotal______forlivingexpenses.
PromptnessisimportantinAmericanbusiness,academic,andsocialsettings.Theimportanceofpunctualityistaughttoyoungch
Mother:Danny!Don’tmakeanysoundwhenyouhaveyoursoup.Danny:Yes,Mum.Father:______.He’sonlyachild.
Therealestatecorporationislookingfor______.Whichofthefollowingdotheynotprefer?
Tom:Youareplayingguitarwell.Canyoureadmusic?Charles:No,Idon’t.Ijustlistentosongsontheradioandthenplayth
Roger:Hurryup!Wedon’thavemuchtimeleft.Dick:______.Westillhavetwohours.Roger:Comeon!Thisismyfirsttimeever
Manufacturingcompaniesspendmillionsofpoundstryingtoconvincecustomersthattheftproductsare______tothoseofothers.
Mary:(afterwork)ShallIpunchoutforyou,Juliet?I’mleavingnow.Juliet:__________.I’vetoworkovertime.
随机试题
Heaskedusifwewould______tosharearoom.
下列有关膈的说法,错误的是()
关于芳香水剂的叙述不正确的是
在建设工程标底的编制过程中,必须考虑的因素有()。
背景A公司参与远离所在地炼钢厂的机电安装工程总承包的投标,投标前做了如下工作:(1)分析了招标文件工程范围,本工程含机械设备安装、电气及自动化系统安装、钢结构及非标准件制作安装、工业给水排水施工、防腐及保温工程、筑炉工程。并分析了本公司
股票回购的方式有()。
《旅游法》规定,景区应当在()公示门票价格、另行收费的价格及团体收费价格。
由于宪法是国家的根本大法,统治阶级如果不是有意着眼于改革,一般不会轻易地修改宪法,加之宪法自身都做了严格修改程序的宣告,使得宪法的修改不会轻易发生。鉴于此,宪法规范在形式上具有()。
Whatistrueaccordingtothepassage?
Whoneedsapublisher?BobYoung,CEOofprint-on-demandserviceLulu.com,saysthatthepublishingand【1】ofbooksonlinewilln
最新回复
(
0
)