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
46
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
A、AbilitytocombinetechnologyandentertainmentB、Abilitytomakeeverystoryaslongaspossible.C、Abilitytofindfamousac
A、Sheearnedalotofmoney.B、Shelearnedmanythings.C、Shewasacquaintedwithmanypeople.D、Shebecameanartmajor.B①选项都是
EatingOurYoung[A]AtFeltonvilleSchoolofArtsandSciences,amiddleschoolinapoorneighborhoodofPhiladelphia,thesch
A、Enhancethecontestsofforce.B、Changepeople’soldmentalhabits.C、Changepeople’sideologies.D、Persuademankindtolivew
KyleMaguirewantedtoattendtheUniversityofNebraskaassoonashegraduatedfromhighschoolyearsago.AnaspiringWebdev
Afterdecadesofdecline,theshareofmotherswhostayhomewiththeirchildrenhas【C1】______risenoverthelastseveralyears
A、Treescanprotectcropsfromwind.B、Cropsgrowingontreeshelpfeedpeople.C、Cropsandtreescannotgrowinonefield.D、Tr
A、Thepopulationwillincreaseuncontrollably.B、Peoplewillsufferfrommoreseriouslackoffood.C、800millionpeoplewilldi
Ofallthe【C1】______ofagoodnight’ssleep,dreamsseemtobeleastwithinourcontrol.Indreams,awindowopensintoaworld
随机试题
避免在300~500℃时矫正,主要是为了防止___________。
氯霉素的最严重不良反应是
技术方案的偿债能力是指分析和判断财务主体的偿债能力,其不包括()。
下列选项中属于我国银行担保类业务的有()。
下列法律事实中,属于法律事件的是()。
开门和关门是人生中含意最深的动作。没有人知道,当他打开一扇门时,有什么在等待着他。门的意义就是把隐藏在它内部的事物加以掩盖,给心儿造成悬念。门是隐秘、回避的象征,是心灵躲进极乐的静谧或悲伤的秘密搏斗的象征。无论一个人在哪儿,只要他在一扇关着的门的后面,他就
①即是说,要使知(对象)变成力量(主体),还需要某种科学的选择、组织、建构、融化的工夫②创造必须有学问。在一定意义上,创造是建立在知识的基础之上的③这样才能使知识纳入你的智力结构,成为你的能力,符合你的需要,而为你自由驾驭,而不只是像机
政协提案:是政协委员以个人、联名或本党派、团体的名义向人民政协组织,并通过政协组织向人民代表大会或人民政府就有关国家或地方大政方针、社会生产等重大问题提出意见和建议的形式。据此定义,下列属于政协提案的是()。
Ofthethreebrothers,theyoungestruns______.
Readthefollowingparagraphandthen"writearesponsepaperofabout250to300words.WriteitneatlyonANSWERSHEET(2).
最新回复
(
0
)