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
2023-10-16
65
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.
SUMMARY:
Co-evolution is【61】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【62】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【63】to both species. In Tasmania, the skink lizards chew the red petals of【64】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【65】never did. [br]
选项
答案
intact
解析
(第四段指出87%of flowers with the petals torn off did so,did so指上文提到的left intact。)
转载请注明原文地址:https://tihaiku.com/zcyy/3102408.html
相关试题推荐
Pickingflowersintheparkisabsolutely______.A、avoidedB、rejectedC、prohibit
Jimmy:Ithinkhoneybeesareveryusefulinsects.Theymakehoneyforus.Amy:_
-WhatamIgoingtodoaboutapresentforCarol?-You______someflowers.A、mig
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
随机试题
[originaltext]W:Whatareyoulaughingabout?M:Ijustsawtheseriousadverti
(1)Theymakesomeoftheworld’sbest-lovedproducts.Theirlogosareinstan
社区获得性肺炎,青壮年和无基础疾病的CAP患者选用()A:氧氟沙星 B:红霉
A.下肢静脉顺行造影 B.动脉造影 C.Buerger试验 D.深浅静脉功
患者,女,30岁。烦热干渴,头痛,牙痛,牙龈出血,舌红苔黄而干。治疗应首选A.龙
财务趋势分析的主要方法有:A.比率分析法 B.杜邦分析法 C.比较财务报表法
评估睡眠障碍最重要的检查方法是()。A.头颅CT B.脑电图 C.头颅DSA
根据下列资料回答问题。 2010年,我国进出口贸易总额为29727.6亿美元
基于认知的选择性,当消费者面对众多营销刺激时,一般更容易选择( )的外部刺激。
A.左移寄存器 B.右移寄存器 C.具有取数功能的数据存储器 D.具有存数
最新回复
(
0
)