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
Birds that are literally half-asleep—with one brain hemisphere alert and the other sleeping—control which side of the brain rema
Birds that are literally half-asleep—with one brain hemisphere alert and the other sleeping—control which side of the brain rema
admin
2019-06-23
72
问题
Birds that are literally half-asleep—with one brain hemisphere alert and the other sleeping—control which side of the brain remains awake, according to a new study of sleeping ducks.
Earlier studies have documented half-brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere’s eye stays open and alert. Birds also can sleep with both hemispheres resting at once.
Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable, end-of-the-row sleepers. Sure enough, the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction.
Also, birds doping(打盹)at the end of the line resorted to single-hemisphere sleep, rather than total relaxation, more often than inner ducks did. Rotating 16 birds through the positions in a four-duck row, the researchers found outer birds half-asleep during some 32 percent of dozing time versus about 12 percent for birds in internal spots.
"We believe this is the first evidence for an animal behaviorally controlling sleep and wakefulness simultaneously in different regions of the brain," the researchers say.
The results provide the best evidence for a long-standing supposition that single-hemisphere sleep evolved as creatures scanned for enemies. The preference for opening an eye on the lookout side could be widespread, he predicts. He’s seen it in a pair of birds dozing side-by-side in the zoo and in a single pet bird sleeping by a mirror. The mirror-side eye closed as if the reflection were a companion and the other eye stayed open.
Useful as half-sleeping might be, it’s only been found in birds and such water mammals(哺乳动物)as dolphins, whales, and seals. Perhaps keeping one side of the brain awake allows a sleeping animal to surface occasionally to avoid drowning.
Studies of birds may offer unique insights into sleep. Jerome M. Siegel of the UCLA says he wonders if birds’ half-brain sleep "is just the tip of the iceberg(冰山)." He speculates that more examples may turn up when we take a closer look at other species.
A new study on birds’ sleep has revealed that_____.
选项
A、half-brain sleep is found in a wide variety of birds
B、half-brain sleep is characterized by slow brain waves
C、birds can control their half-brain sleep consciously
D、birds seldom sleep with the whole of their brain at rest
答案
C
解析
第1段提到“根据对睡鸭的一项新研究,那些真正进行半脑睡眠的鸟类——它们半个大脑警醒,半个大脑沉睡——控制着让哪一半大脑保持清醒”,也就是说能自觉地控制大脑的状况,C正确。A和B是早期研究的结果:D与文章的意思不符。
转载请注明原文地址:https://kaotiyun.com/show/83X7777K
0
大学英语六级
相关试题推荐
Inthepushtocuttheamountofcarbonwereleaseintotheatmosphere,solutionsusuallyfocusonhowtoreduceourpoweruseo
DoBritain’sEnergyFirmsServethePublicInterest?[A]Capitalismisthebestandworstofsystems.Lefttoitself,itwillem
A、Finishatextbookassignment.B、Reviewforthefinalexamination.C、Chooseproperresearchtopics.D、Prepareanoutlinefora
A、Heisawell-knowncomicmoviestar.B、Heisafamoustechnicianofmobiletechnology.C、HeisoneofHollywood’srenownedfil
A、Hemustexploithistalent.B、Hemustimprovehisperformance.C、Hemustdefeathisnervousness.D、Hemustwintheaudience’s
Theincreaseinglobaltrademeansthatinternationalcompaniescannotaffordtomakecostlyadvertisingmistakesiftheywantt
KyleMaguirewantedtoattendtheUniversityofNebraskaassoonashegraduatedfromhighschoolyearsago.AnaspiringWebdev
Everyotherweekitseemsanewstudycomesoutthataddstoouralready-formidablestoreofparentalworries.Butevenbythose
A、Sleepinginanopenenvironment.B、Usingfuelinsteadofelectricity.C、Usingsmallandmovablegasgenerators.D、Short-termc
A、ItwasadesignschoollocatedinGermany.B、ItwasanAmericanartmovement.C、ItwasascenicspotinGermany.D、Itwasthe
随机试题
不是混凝土入仓铺料的方法有()。
检验感受性大小的基本指标是【】
设f(x)=求f(x)dx.
肠鸣音减弱指至少多少分钟才听到1次肠鸣音
乙为水泥厂,甲为水泥销售公司。甲、乙订立一购销合同,约定乙于6月1日前送水泥1000吨给甲;甲支付定金10万元给乙。后乙于6月2日将1000吨水泥运至甲处。甲以乙违约(迟延履行1天)为由,要求乙双倍返还定金20万元。以下说法错误的是:
建设工程项目投资决策完成后,控制工程造价的关键在于()。
下列有关培训制度的推行与完善说法错误的是()
根据皮亚杰的道德发展阶段理论,处于()阶段的儿童对外在权威表现出绝对尊敬和顺从的愿望,他们认为服从、听话就是好孩子,否则就是错的,是坏孩子。
《麦秸垛》《玫瑰门》和《笨花》的作者都是铁凝。()
小张将新买的手机开机密码设为由1、3,6、9组成的四位数,第二天,小张开机时忘了四位数的具体排序,只记得数字3和9相邻且1不在最后。问:小张要试多少次才能确保打开手机?
最新回复
(
0
)