首页
登录
职称英语
[originaltext] Thefiddler crab ( 招潮蟹) is a living clock. It indicates the ti
[originaltext] Thefiddler crab ( 招潮蟹) is a living clock. It indicates the ti
游客
2023-09-12
88
管理
问题
Thefiddler crab ( 招潮蟹) is a living clock. It indicates the time of day by the color of its skin, which is dark by day and pale by night. The crab’s changing skin color follows a regular 24-hour cycle that exactly matches the daily rhythm of the sun.
Does the crab actually keep time, or does its skin simply respond to the sun’s rays, changing color according to the amount of light that strikes it? To find out, biologists kept crabs in a dark room for two months. Even without daylight, the crabs’skin color continued to change precisely on schedule.
This characteristic probably evolved in response to the rhythm of the sun, to help protect the crab from sunlight and enemies. After millions of years it has become completely regulated inside the living body of the crab.
The biologists noticed that once each day the color of the fiddler crab is especially dark, and that each day this occurs 50 minutes later than on the day before. From this they discovered that each crab follows not only the rhythm of the sun but also that of the tides. The crab’s period of greatest darkening is precisely the time of low tide on the beach where it is caught.
选项
A、The Rhythmic Cycle of the Sun and the Tide
B、Discoveries in Biology
C、A Scientific Study
D、A Living Clock
答案
D
解析
概括归纳题 文章的关键词是fiddler crab,文章主要讲述了其肤色的规律性变化。
转载请注明原文地址:http://tihaiku.com/zcyy/3008745.html
相关试题推荐
【B1】______[br]【B10】______[originaltext]Thedog,calledPrince,wasan(
【B1】______[br]【B7】______[originaltext]Thedog,calledPrince,wasan(2
【B1】______[br]【B5】______[originaltext]Thedog,calledPrince,wasan(2
【B1】______[br]【B4】______[originaltext]Thedog,calledPrince,wasan(2
【B1】______[br]【B2】______[originaltext]Thedog,calledPrince,wasan(2
[originaltext]OnecrossingoftheAtlanticisverymuchlikeanother;andpe
[originaltext]Ifyou’vebeenoncampusforverylong,I’mcertainthatyo
[originaltext]Ifyou’vebeenoncampusforverylong,I’mcertainthatyo
[originaltext]Livingthingstakefromtheirenvironmentandgivebacktothe
[originaltext]Livingthingstakefromtheirenvironmentandgivebacktothe
随机试题
Recoveryfromjetlagcantakeaslongasadayforeverytimezonecrossed.
IsitanywonderthatAmericaisalsoacountryofdangerouslyoverweightpe
[originaltext]W:Didyouturnoffthelightsandcheckthelocksonallthedoo
下列不是锥体束病变时的病理反射的是( )。A.巴宾斯基征 B.查多克征 C
如果概念B所表达的对象均在概念A所表达的范围之内;概念A所表达的对象有些在概念B
信念和态度一旦形成就很难改变,会引导消费者习惯地购买某些商品。( )
战略性衡量项目主要有()。A.团队建设 B.队伍建设 C.制度建设 D.企
人类社会是在矛盾运动中发展进步的,构建社会主义和谐社会是一个不断化解社会矛盾的持
泡沫塑料制服装垫肩
运输企业将客车安排在营运区域内多条线路上顺序轮流运行的组织方式是()。A:小循
最新回复
(
0
)