首页
登录
职称英语
As every schoolboy knows, insects pollinate flowers, while birds and mammals
As every schoolboy knows, insects pollinate flowers, while birds and mammals
游客
2024-08-11
40
管理
问题
As every schoolboy knows, insects pollinate flowers, while birds and mammals disperse seeds by eating fruits or transporting burs on their feathers and fur. These are examples of co-evolution, a phenomenon first described by Charles Darwin in The Descent of Man, and Selection in Relation to Sex, published in 1871.
Co-evolution, in which two species have evolved together in response to adaptations that each has imposed on the other, can be extremely subtle. For instance, some animals may help to transfer pollen from one plant to another without acting directly as the carrier themselves. Instead, they make it easier for the pollen to be dispersed by other creatures. Mats Olsson and Richard Shine, of the University of Sydney, and Elisabeth Bak-Olsson, of the University of Gothenburg in Sweden, have discovered, apparently for the first time, such a mutually beneficial arrangement between a reptile and a plant.
For most of the year the Tasmanian snow skink lizard confined to mountain tops in that island is catholic in what it eats. But when the honey-bush is in bloom, the skinks make a point of tearing off the tough, red petals that enclose the rest of the flower. They chew them to extract the nectar and spit out what is left. At first sight, this skink-savaging may not seem all that helpful to the honey-bush. But it is. It exposes the reproductive parts of the flowers, thereby allowing pollinating insects to get at them. Dr. Olsson and his colleagues found that flowers with the petals left intact never produced seed. But, according to their paper in the Biological Journal of the Linnean Society, 87% of flowers with the petals torn off did so.
To check that it was the skinks alone that were the plants’ little helpers, the researchers placed cages around some honey-bushes. Virtually all of the petals were removed from the flowers on bushes without cages. Only 16% of the caged bushes had their petals ripped off, possibly by high winds battering them.
Dr. Olsson found no evidence of pollen being carried on a skink and so concluded that the lizards play no role in transporting honey-bush pollen from one flower to another. But he did see a range of insects: wasps, flies, bumble-bees and others feeding from honey-bush flowers that had no petals covering them. Without the petals removed, it was impossible for insects to do any pollinating.
Question 71 to 75
Complete the summary below with information from the passage, using three words or fewer for each blank.
Co-evolution is【R1】______described by Charles Darwin in The Descent of Man. In the process of co-evolution, two species may have to respond to adaptations they have imposed on each other.
For example, some animals may not carry【R2】______from one plant to another. They may help by making it easier for other creatures to disperse the pollen from one plant to another. Such an arrangement seems【R3】______to both species. In Tasmania, the skink lizards chew the red petals of【R4】______and spit out what is left. In doing so, they expose the reproductive parts of the flower and enable pollinating insects to reach them. It was discovered that 87% of these flowers produced seeds. Conversely, flowers with petals remaining【R5】______never did. [br] 【R2】
选项
答案
Pollen
解析
(由some animals may help to…directly as the carrier themselves“它们会传递花粉,但是自己却不是直接的传递者”可知答案。)
转载请注明原文地址:https://tihaiku.com/zcyy/3715636.html
相关试题推荐
Jimmy:Ithinkhoneybeesareveryusefulinsects.Theymakehoneyforus.Amy:_
Mygardenhaslargetrees.Mygardenhasflowerswhichsmelllovelywheninbloo
-WhatamIgoingtodoaboutapresentforCarol?-You______someflowers.A、mig
Mygardenhaslargetrees.Mygardenhasflowerswhichsmelllovelywheninbloo
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
随机试题
Oneday,Ihappenedto(碰巧)talktoastranger(陌生人,异乡人)onthebus.Whenhefou
WhatbothersNancyaboutherneighbor’sson?[br][originaltext]W:Howareyour
开关柜操作应平稳无卡涩,禁止强行操作。
根据我国有关法规确定保护的城市历史文化遗产的三个层次是()。A.历史文化名城、
如果从一个正态分布中,将上端的少数极端值去掉,以下统计量不会受到影响的是( )
发行人申请股票在深圳证券交易所创业板上市,应当符合()条件。 A.股票已公开
临床实践验证,一些毒物有相应的特效拮抗剂。因此,在进行排出毒物的同时,应积极使用
既要考虑劳动者维持原来本人及其家庭基本生活,进行劳动生产力生产和再生产的最直接、
下列不属于水利水电工程项目按级划分等级的是( )。A.单位工程 B.单元工程
下列个人所得,属于居民综合所得并按纳税年度合并计算个人所得税的包括()。A.工
最新回复
(
0
)