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
2011-01-02
20
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, ac cording 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 hemi sphere 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, cud-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 dozing at the end of the line resorted to single-hemi sphere sleep, rather than total relaxation, more often than inner ducks did. Rotating 16 birds through the positions in a four-duck row, the re searchers 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 wide spread, 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 as dolphins, whales, and seals. Perhaps keeping one side of the brain awake allows a sleeping animal to surface occasion ally 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." 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、halt-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
根据文章第一段以及第三至第六段可知,对最新的鸟类睡眠研究表明,鸟儿可以有意识地控制自己的半脑睡眠。这几段举例说明了对这个问题实验的情况。尽管在文章第二段中也提到了[A]、[B]和[D],但那是文献上记载的以前研究的情况(Earlier studies have document ed.)。故均不是正确答案。
转载请注明原文地址:https://kaotiyun.com/show/VheO777K
0
专业英语八级
相关试题推荐
ThediscoveryoftheAntarcticnotonlyprovedoneofthemostinterestingofallgeographicaladventures,butcreatedwhatmigh
Whichofthefollowingstatementsisnottrue?
HenryFielding,thefamousnovelistwhowasalsoaLondonmagistrate,oncemadeanightraidto【M1】_
AustralianTherearetwocommonsetimagesoftheAustralianmale:a)the【1】______andNeanderthalmale--greatforabi
Sciencehaslonghadanuneasyrelationshipwithotheraspectsofculture.ThinkofGallileo’s17thcenturytrialforhisrebell
Theroleofandtreatmentofthehousewife,whichisreallythemajorboneofcontentioninsocialsecurityreform,has,ofcour
SANTEE,CALIF--WhennewsbrokeaboutthemayhemandkillingatSantanaHighSchool,CharlesWilliamsfranticallydashedtothe
Anumberoffactorsrelatedtothevoicerevealthepersonalityofthespeaker.Thefirstisthebroadareaofcommunication,wh
A、ManydetaineesinGuantanamoBayhavebeenheldformorethan2years.B、U.Sgovernmentdoesn’tpermitWilnertodiscusstheir
SincejoiningtheEuropeanEconomicCommunityin______,BritainhasadoptedtheCommunitysystemofagriculturalsupport.
随机试题
在蒸馏生产中,液泛是容易产生的操作事故,其表现形式是()。
关于十二指肠溃疡的治疗,最佳措施是
A、普鲁卡因B、利多卡因C、地卡因D、可卡因E、氯乙烷比较理想的冷冻麻醉药是
下列哪项不属于儿科抢救室需配备的设备
通信电源直流供电系统包括()等部分。
春节的节日活动有()。
我国()是世界上种类最多的国家。
甲男将女同事汪某骗至宾馆,要求与之发生性关系,否则在网上散布汪某的不雅照。汪某对甲破口大骂,甲觉得无趣,遂打消奸淫念头离去。甲的行为属于()(2015年非法学基础课单选第12题)
Formostofhumanhistoryrichpeoplehadthemostleisure.Ontheotherhand,thepoorhavetypicallyworkedpersistently.Hans
下列程序的执行结果为()。publicclassc3{publicstaticvoidmain(Stringargs[]){inti=13,j=10;
最新回复
(
0
)