首页
登录
职称英语
Birds that are literally half asleep — with one brain hemisphere alert and t
Birds that are literally half asleep — with one brain hemisphere alert and t
游客
2024-04-20
1
管理
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 dozing 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. [br] By "just the tip of the iceberg"(Line 2, Para. 8), Siegel suggests that_____.
选项
A、half brain sleep has something to do with icy weather
B、the mystery of half brain sleep is close to being solved
C、most birds living in cold regions tend to be half sleepers
D、half brain sleep is a phenomenon that could exist among other species
答案
D
解析
推理题。本题定位到最后一段:对鸟类的研究可以提供对睡眠的独特认识。他推测当我们对其他物种仔细观察时,就会发现更多的例证。因此选项D说“半脑睡眠这种现象可能存在于其他物种身上”正是“justthe tip of iceberg”所表达的意思。故选D。
转载请注明原文地址:https://www.tihaiku.com/zcyy/3563639.html
相关试题推荐
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnoon
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnoon
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnoon
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnoon
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnoon
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnoon
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnoon
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnoon
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnoon
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnoon
随机试题
[originaltext]Interviewer:It’salmost...uh...thattherehasbeenafeelingor
Peoplethinkingabouttheoriginoflanguageforthefirsttimeusuallyarri
Atlasthewas(please)______withoneofhispictureofthemouse.pleased本题测试的
原发性婴儿痉挛症首选的药物是A.苯巴比妥 B.氯硝西泮 C.ACTH或泼尼松
甲和乙签订了一份合同,约定同时履行。甲在自己还没有履行的情况下,请求乙履行,乙予
下列可以鉴别心绞痛和心肌梗死的是( )。A.舌下含服硝酸甘油是否缓解 B.疼
某患者单次静脉注射某药物10mg,已知t1/2=4h,V=60L,请问给药30m
根据下列资料回答问题。 以下为某省的人口失业率图表。其中,黑色部分表示该省全省
下列凝血因子中,最不稳定的是( )。A.因子Ⅴ B.因子Ⅶ C.因子Ⅹ
在数字有线电视传输网络中,系统管理部分的内容包括()。A.对传输码流进行检查或监
最新回复
(
0
)