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
34
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
AlthoughthepoliceAaregivenconsiderableauthoritybysocietytoenforceBitslaws,theygetarelativelylowsalaryascompa
TodayblackchildreninsouthAfricaarestillreluctanttostudysubjectsfromwhichtheywereeffectivelybarredforsolong.
Thisbookisa______ofradioscripts,inwhichweseektoexplainhowthewordsandexpressionsbecomeapartofourlanguage.
A:Youseemtohavealotofworktodoinyouroffice.You’vealwaysbeenworkingovertime.B:______
Whatpartdoesthefemaleseahorseplayinhavingbabies?Theauthorsuggeststhatwhenseahorsebabiesarereadytobeborn
Averyimportantworldproblemistheincreasingnumberofpeoplewhoactuallyinhabitthisplanet.Thelimitedamountoflanda
ThePrimeMinisterexplainedthenewpolicyofhisgovernmentingreatdetailsoastowinthesupportofhispeople.
Attitudesofrespect,modestyandfairplaycangrowonlyoutofslowlyacquiredskillsthatparentsteachtheirchildrenoverm
Thelocalresidentswereunhappyaboutthecurfewinthisregionanddecidedto_____it.
WithbutprotectionA.Itusuallygivesinadequate(62)______fromtheweatherB.notonlyinsomedevelopingcountrieswherebic
随机试题
中国是一个社会主义国家,因此在处理国际事务中,应以社会制度的异同来作为判断是非的标准。
A.普通片B.舌下片C.糖衣片D.可溶片E.肠溶衣片要求在15分钟内崩解或溶化的片剂是
正常血乳酸波动范围是
静力触探适用于()。
属于公文眉首部分的要素有()。
课堂教学是教学的()。
一个人的行为对旁观者福利的影响,被称为()。
新形势下,既要看到我国发展面临的重要战略机遇期,又要看到我国面临的挑战;既要看到国内因素,也要看到国际因素。其中,我国发展面临的国内困难和挑战,主要体现在
Sub过程与Function过程最根本的区别是()。
ConversationalSkillsPeoplewhousuallymakeusfeelcomfortableinconversationsaregoodtalkers.Andtheyhavesomething
最新回复
(
0
)