首页
登录
职称英语
Humans and nearly all other animals vary their level of activity according t
Humans and nearly all other animals vary their level of activity according t
游客
2024-03-05
48
管理
问题
Humans and nearly all other animals vary their level of activity according to the time of day. Daily rhythms are not simply responses to daylight and darkness or to other signs of the time of day. They are generated by the animals themselves. This is shown by experiments in which animals live in artificial surroundings that do not vary with time of day. They experience no daylight, no darkness, no day-night swings of temperature, and no contact with other animals that "know" the time of day. Under such conditions, the animals continue to exhibit near-daily rhythms of activity and rest. These rhythms must be generated by the animals’ own inner "clock". Such a biological clock is normally reset every day, mainly by the cycle of daylight and darkness. An animal’s activity and rest periods are thereby kept "in step" with the environment and with the activity cycles of other animals.
Daily periods of reduced activity serve at least two purposes. First, they allow the animal to save its resources for the time of day at which it is best suited to compete for food. Second, they make the animal less conspicuous to its enemies. The resting condition is reversible. Animals can become active at unusual times of day if they detect risks or if opportunities for feeding develop at times of shortage.
Whether the resting state of an animal qualifies as "sleep", however, depends on the complexity of its nervous system. Mammals and birds are the animals in which true sleep, of the nature indicated above, has been observed. Other animals exhibit resting periods.
选项
答案
animals have their own inner clock
解析
由题干experiments可定位至首段第四句:在人工环境下,动物仍然表现出平常的作息习惯,第七句做出推断说动物们一定有自己的内部时钟。
转载请注明原文地址:https://tihaiku.com/zcyy/3508393.html
相关试题推荐
C根据Accordingtothestatisticalstudy和supercentenarians定位到C段。该段说,许多百岁老人不但没有行动不便等
[originaltext]Accordingtolatestpsychologicalresearch,appearancedoesa
[originaltext]Timeflieswhenyou’rehavingfun.[16]Enrolmentisnearlyo
[originaltext]Wethinkofaerobicsasbeingahighimpactactivitybutactu
AccordingtoascientificstudypublishedinApril,2015,birdshaveshownt
AccordingtoascientificstudypublishedinApril,2015,birdshaveshownt
AccordingtoascientificstudypublishedinApril,2015,birdshaveshownt
AccordingtoascientificstudypublishedinApril,2015,birdshaveshownt
AccordingtoascientificstudypublishedinApril,2015,birdshaveshownt
AccordingtoascientificstudypublishedinApril,2015,birdshaveshownt
随机试题
A、Hehadalreadyfoundajob.B、Hedidn’tliketheconstructionwork.C、Hethoug
Secondhandsmokeisaccountablefor42,000deathsannuallytononsmokersin
[originaltext]ScottDunnrecentlyawokefromamedically-inducedsleephe’d
[originaltext]W:ProfessorMarnes,Iwonderifyoucanfillmeinonyourlectu
哲学上的一元论就是承认()A.世界是物质 B.世界在本质上是精神 C.世界是
对个人投资者买卖基金单位获得的差价收入,在对个人买卖股票的差价收入未恢复征收个人
面部危险三角区感染时禁用热疗的主要原因是()。A.热疗可促进血液循环,加重皮下
下列选项中不属于资源开发方案中内容的有( )。A.项目需要占用的重要资源品种B.
(2020年真题)根据《全国海洋主体功能区规划》,关于海洋特别保护区管理要求的说
某城市综合管线与道路工程,该工程管线包括给水、污水、雨水、热力和燃气管道工程。除
最新回复
(
0
)