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
2023-10-15
51
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【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] 【R4】
选项
答案
the honey-bush
解析
(由文章But when the honey-bush is in bloom.…the rest of the flower.They chew them toextract the nectar and spit out what is left可知。Them指的是the honey-bush。)
转载请注明原文地址:http://tihaiku.com/zcyy/3101325.html
相关试题推荐
-WhatamIgoingtodoaboutapresentforCarol?-You______someflowers.A、mig
Mygardenhaslargetrees.Mygardenhasflowerswhichsmelllovelywheninbloo
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
随机试题
Duringastateofdeeprelaxation,severalphysiologicalchangestakeplace
Therelianceoncreditreportsinhiringisbecomingwidespread.Asurveyb
某试验室开展一条公路路基上的CBR试验,试料最大粒径为40mm.请结合试验内容完
45岁,女性,进行性消瘦5个月,下腹部坠胀1个月。月经正常,无痛经。GPAL,
A.四日极量 B.七日常用量 C.二日极量 D.三日常用量 E.一次常用
A.外阴炎 B.滴虫性阴道炎 C.外阴阴道假丝酵母菌病 D.前庭大腺囊肿
集合资产管理合同由()三方签署。A:证券公司 B:证券登记结算机构 C:资产
案例四: 一般资料:求助者,女性,32岁,公务员。 案例介绍:求助者两年前离
甲公司2018年税前会计利润为130万元,所得税税率为25%,当年发生
下列不符合挖孔灌注桩施工的安全要求的是( )。A.施工前应制订专项安全技术方案
最新回复
(
0
)