首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
As every schoolboy knows, insects pollinate flowers, while birds and mammals disperse seeds by eating fruits or transporting bur
As every schoolboy knows, insects pollinate flowers, while birds and mammals disperse seeds by eating fruits or transporting bur
admin
2013-01-10
65
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.
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 to extract 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:https://kaotiyun.com/show/uVAK777K
本试题收录于:
B类竞赛(英语专业本科专科)题库大学生英语竞赛(NECCS)分类
0
B类竞赛(英语专业本科专科)
大学生英语竞赛(NECCS)
相关试题推荐
"Home,sweethome"isaphrasethatexpressesanessentialattitudeintheUnitedStates.Whethertherealityoflifeinthefami
"Home,sweethome"isaphrasethatexpressesanessentialattitudeintheUnitedStates.Whethertherealityoflifeinthefami
Livinginaforeigncountryisfun,butitisn’talwayseasy.Therearemanydifferencesbetweenculturesandalthoughsomeofth
教师被人们称为“园丁”、“人类灵魂的工程师”,是受到全社会尊重的一种职业。每年的10月5日为世界教师日。【T1】该节日旨在赞扬和感谢全世界教师为教育事业和人类作出的贡献(contribution)。同时希望引起对教师的世界性关注,帮助教师维护自身权益。
Changesinthewaypeoplelivebringaboutchangesinthejobsthattheydo.Moreandmorepeopleliveintownsandcitiesinste
Heisoneofthosemenwho,Iamsure,alwaysdo________besteveninmosttryingcircumstances.
ThefollowingitemshavebeendestroyedEXCEPT________.
Youseethefollowingadvertisementinaninternationalmagazine.Writealetterofapplicationin120words.Donotincludeany
Mr.Jones’daughterwasborntwomonthsafterthemonthwhichbeginswiththesecondletterafterthethirteenthletterofthea
______informationprovidedbymembersofthepublic,thepolicewouldhaveamuchmoredifficultjob.
随机试题
Whatwastheoriginoftheoilwhichnowdrivesourmotorcarsandaircraft?Scientistsare【C1】______aboutthe【C2】______ofcoal,
某产妇,产后第6天发热达40℃,恶露多而浑浊,有臭味,子宫复旧不佳,有压痛。下述哪一项护理不妥
临床用简便方法测定能量代谢,必须测定的数据是
质监总站负责公路工程综合类甲级、乙级,公路工程专项类及水运工程材料类及结构类甲级、乙级的等级评定工作。()
下列关于用地规划高程应高干地下水位的说法中,错误的是()。
信号弹在白天发射的时候一般用()。
材料一:2010年甲伪造了其他单位的合同章和公章后,假冒该公司的经理对乙说:“我聘你做业务员。”甲和一个乡镇企业签订合同购买衬衣5000件,金额15万元,约定定金3万元。甲找到乙说明自己的真实身份,让乙借3万元钱,乙对甲说:“要钱没有,但可以帮你联系销路。
中华传统美德和中国革命道德是一脉相承的。其一脉相承性主要体现在
以下关于MsgBox的叙述中,错误的是
A、Itwastheworld’sworstearthquakein80years.B、Itcreatedgreatpanicamongtheresidents.C、Mostresidentsspentthenigh
最新回复
(
0
)