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
2024-08-13
15
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【51】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.【52】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【53】to both species. In Tasmania, the skink lizards chew the red petals of【54】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【55】never did. [br]
选项
答案
intact
解析
(第四段指出87% off lowers 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/3717528.html
相关试题推荐
-WhatamIgoingtodoaboutapresentforCarol?-You______someflowers.A、mig
Mygardenhaslargetrees.Mygardenhasflowerswhichsmelllovelywheninbloo
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
随机试题
Mostworthwhilecareersrequiresomekindofspecializedtraining.Ideally,
Therearesuperstitionsattachedtonumbers;eventhoseancientGreeksbelie
在高层建筑中,燃油燃气锅炉房应该布置在()。A.建筑的地下三层靠外墙部分
A.表情淡漠无欲 B.蝶形红斑 C.面部潮红 D.面色发黄,巩膜黄染 E
急腹症病人腹腔内穿刺液为带臭味的血性液,最可能为()A.肠套叠 B.胆囊
对任何内幕消息的价值都持否定态度的是()。A.弱式有效市场假设 B.半强式有
A.纯水B.液氨C.冰醋酸D.甲苯E.甲醇非质子性溶剂应选择的溶剂为
在人机系统设计过程中,减少操作者的紧张和体力消耗来提高安全性,并以此改善机器的操
建设项目竣工环境保护验收监测时,采用的验收标准是()。A.初步设计时确定的设计指
反射镜和跟踪设备属于( )的组成。A.火力发电设备 B.塔式太阳能光热发电设备
最新回复
(
0
)