您好,欢迎来到教培网!请登录免费注册选课学习指南
广州
教培网
外语/小语种电脑/IT/设计职业技能学历教育
深圳海龙教育轮播1深圳海龙教育轮播2深圳海龙教育轮播3深圳海龙教育轮播4深圳海龙教育轮播5
学校环境校区与课堂实景
查看学校相册

深圳海龙教育

V2
4.95人评价
雅思18门课程3个校区3人预约
正规学校助学补贴优质服务多校区资质认证
校区
深圳总校、海龙教育龙岗校区、海龙教育南山校区
地址
深圳市福田区深南大道NEO企业大厦B座20楼
电话
18347319277
简介
深圳市海龙教育服务有限公司自2003年成立伊始,一直致力于TOEFL、SSAT、SAT、AP等出国留学考试培训、研究及面向北美地区的名校留学申请。作为珠三角地区 详情
当前位置:教培网>深圳海龙教育>学校动态>托福阅读机经背景科学类:吃虫植物猪笼草

托福阅读机经背景科学类:吃虫植物猪笼草

作者:教培网来源:教培网地区:深圳

2013-12-07 吃动物的植物,全世界有500多种,其中,以猪笼草的捕虫器精巧和复杂。猪笼草大多数生长在印度洋群岛、马达加斯加、斯里兰卡、印度尼西亚等潮湿热带森林里,我国广东、云南等省也有这种植物。猪笼草吃虫,全靠它奇特的叶子 它的叶片中脉伸出去变成卷须,可以攀附着别的东西向上升。卷的顶部生出一个囊状物,好象奶瓶子一样,口上有一个盖,能开也能关。瓶口边缘向内卷,瓶内有半瓶子水液。瓶口内壁能分泌又甜又香的蜜汁,贪吃的小昆虫闻到香味就会爬过去吃蜜。也许就在它们吃得正得意的时候,脚下突然一滑,一头栽到瓶中,被水液粘住了,再也无法逃命。于是猪笼草得到了一顿美餐。其它吃虫植物如茅膏菜、毛毡苔、捕蝇草等,虽然也能捕捉昆虫,但它们的捕虫工具,远不及猪笼草的精巧复杂。

Pitcher plants are carnivorous plants whose prey-trapping mechanism features a deep cavity filled with liquid known as a pitfall trap. It has been widely assumed that the various sorts of pitfall trap evolved from rolled leaves, with selection pressure favouring more deeply cupped leaves over evolutionary time. However, some pitcher plant genera (such as Nepenthes) are placed within clades consisting mostly of flypaper traps: this indicates that this view may be too simplistic, and some pitchers may have evolved from flypaper traps by loss of mucilage. Whatever their evolutionary origins, foraging, flying or crawling insects such as flies are attracted to the cavity formed by the cupped leaf, often by visual lures such as anthocyanin pigments, and nectar bribes. The sides of the pitcher are slippery and may be grooved in such a way so as to ensure that the insects cannot climb out. The small bodies of liquid contained within the pitcher traps are called phytotelmata. They drown the insect, and the body of it is gradually dissolved. This may occur by bacterial action (the bacteria being washed into the pitcher by rainfall) or by enzymes secreted by the plant itself. Furthermore, some pitcher plants contain mutualistic insect larvae, which feed on trapped prey, and whose excreta the plant absorbs.[1] Whatever the mechanism of digestion, the prey items are converted into a solution of amino acids, peptides, phosphates, ammonium and urea, from which the plant obtains its mineral nutrition (particularly nitrogen and phosphorus)。

Like all carnivorous plants, they occur in locations where the soil is too poor in minerals and/or too acidic for most plants to be able to grow. 本篇关键词: Pitcher plants carnivorous plants mucilage cupped leaf slippery grooved phytotelmata amino acids peptides phosphates ammonium and urea nitrogen and phosphorus 以上即为关于托福阅读机经背景科学类:会吃虫子的植物的详细内容,对于同学们积累托福阅读机经的背景知识有一定帮助,也希望同学们在日常复习中自己也有意识地积累一些托福阅读背景素材。

分享到:

相关课程

官方授权声明

尊敬的平台会员您好,[深圳海龙教育]资料由平台整理展示,资质、课程、校区、图片和文案均可在后台维护。如需了解[深圳海龙教育]服务明细或申请试听服务,请点击。

公开资料整理 | 待机构认领确认