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
考研
A nocturnal(夜间活动的)moth has become the first animal known to see colours in the dead of night. The moth uses this visual talent t
A nocturnal(夜间活动的)moth has become the first animal known to see colours in the dead of night. The moth uses this visual talent t
admin
2010-01-13
97
问题
A nocturnal(夜间活动的)moth has become the first animal known to see colours in the dead of night. The moth uses this visual talent to find yellow, nectar-packed flowers in the dark, but the finding suggests that other, species also use colour vision at night.
Nocturnal moths were thought to find flowers by looking for bright petals against a darker, leafy background. This difference in brightness explains why a yellow flower stands out from green leaves on a black and white photo.
To test this idea, researchers at Lund University in Sweden trained nocturnal elephant hawkmoths(豆天蛾)to pick out yellow or blue artificial flowers from eight other flowers of varying shades of grey. They then made moths perform the trick in conditions as dark as a starry but moonless night.
The researchers expected the moths to do badly, but to their surprise the insects picked the correct flower 90 per cent of the time. But the moths could not distinguish between lighter and darker shades of a coloured flower, even though they could still tell both from grey. "This tells us it’s not a brightness-related cue,” says Almut Kelber, the sensory biologist leading the Lund team. "They could only have used the spectral(光谱的)composition of the signals—which we call colour."
The moths use three separate colour receptors: blue, green and ultraviolet. At night, that leaves so little light per receptor that the insects should be almost blind. But hawkmoths have a host of adaptations to compensate. One is a mirror-like structure at the base of the eye, which reflects the light across the photoreceptors for a second time. The structure of the compound eye also allows each facet to supplement the light that strikes it with light from as many as 600 others.
Kelber suspects that many other insects, and some higher animals, also use colour vision at night. She plans to look for the ability in nocturnal frogs and toads that use colour to choose their mate. "Why not? she asks. "At night there are just as many colours as during the day."
Which of the following might be the most appropriate title for this passage?
选项
A、How animals see things at night.
B、Moth—the only creature to see things at night.
C、Moths use color to see flowers at night.
D、How many colors can moths see at night.
答案
C
解析
主旨大意题。综合各段的主题句可以看出本文主要是在阐述蛾可以在夜间利用颜色看到花朵,而不是依靠亮度。
转载请注明原文地址:https://kaotiyun.com/show/ocmi777K
0
在职申硕(同等学力)英语
相关试题推荐
组织代谢活动增强时,毛细血管床因代谢产物堆积而开放,这种调节属于
AItisveryhardtobelieveBthatwhenLincolnwasborn,communicationswereCalittlefasterthanDinthedaysofJuliusCaesar
We(cannothardly)expectadolescents(tohaverespect)forthepossessionsofothers(if)theyhavenohopeofattaininganyof
"Businesscasual"wasprevalentseveralyearsagobecause______Whenthe"businesscasual"prevailed,______
Man:Ididn’tknowyougotapromotion.Whydidn’tyoutellmeearliersothatwecouldhavecelebratedit?Woman:Iguessitsl
Man:IfIdon’tfindmywalletprettysoon,Ihavetoreportitstolen.Woman:Holdon!Beforeyoucallthecampussecurityo
Duringthepastyearsthe______ofautomobileaccidentsinNewYorkCityhasdecreased.
Laundryis,afterall,justlaundry.Exceptwhenit’snot.AndProcter&GambleCo.recentlyrealizedthatTide,itssegment-dom
Attitudesofrespect,modestyandfairplaycangrowonlyoutofslowlyacquiredskillsthatparentsteachtheirchildrenoverm
Americansnolongerexpectpublicfigures,whetherinspeechorinwriting,tocommandtheEnglishlanguagewithskillandgift.
随机试题
按有关规定,目前资产评估报告书正文及相关附件的基本内容包括( )。
银行开展银信理财合作,应当有清晰的战略规划,制定符合本行实际的合作战略并经董事会或理事会通过,同时遵守的规定包括()。
针对审计工作底稿的归档或保存,下列表述中,正确的有()。
哲学曾经是一种生活方式。所谓苏格拉底的哲学,不只是他和别人对话的方法,以及他在对话中提出的种种理论,更是他不立文字、浪迹街头、四处与人闲聊的生活方式。哲学从一开始就不是一种书面的研究,而是一种过日子的办法。只不过我们后来都忘了这点,把它变成远离日常的艰深游
伪证罪只能发生在()。
简述梁漱溟乡村建设理论与乡村教育实践。【2015年-云南师大】【2019年-华南师大】
Whenamedicalprocedureortechnologyfirstcomesontothescene,itisalmostinvariablymetwithcontroversyfromallsidesr
TherecentsocialandeconomicchangesintheU.S.havegreatimpactonalltheAmericanhousingsystem.
WheredoesJanework?
Shouldwecareifover150knownspeciesofanimalshave【C1】______fromtheearthinthelastfiftyyears?Shouldwebeconcerned
最新回复
(
0
)