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
32
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/3100653.html
相关试题推荐
Mygardenhaslargetrees.Mygardenhasflowerswhichsmelllovelywheninbloo
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
随机试题
【S1】[br]【S5】C此处需要一个原形动词,因为整篇文章的时态都是一般现在时,而且所填入的词作定语从句的谓语。基于以上分析,无疑generate为正确选
1.题目:选择性必修中册《记念刘和珍君》片段教学 2.内容: 但是,我还有要
A.闭合面内的电荷代数和为零时,闭合面上各点电场强度一定为零 B.闭合面内的电
网络硬件系统包括()。A.计算机系统 B.终端 C.通信设备 D.网络通信
空气幕由空气处理设备、风机、风管系统及空气分布器组成,其中上送式空气幕的特点有(
黄山三大主峰是( )。A.玉京峰 B.莲花峰 C.光明顶 D.天都峰 E
下列不属于教学设计工作一般步骤的是()。A.设计教学目标 B.设计教学媒体
A.缺铁性贫血 B.急性失血性贫血 C.新生儿溶血病 D.真性红细胞增多症
大数法则要求承保的风险具有(),保险公司只有通过广泛开展业务才可以实现集合风险、
从事建筑活动的经济组织应当具备的条件是符合国家规定的() A.注册资本、专
最新回复
(
0
)