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
17
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
Lastnight,itwasstilllightoutwhenIreturnedhomefromwork.Mynewnei
Accordingtothepassage,thecreditcardenablesitsownerto______.[br]The
[originaltext]WinningrecognitionintheannualMichelinGuideisoneofth
地板刨平机和地板磨光机操作中应平缓、稳定,防止尘屑飞扬。连续工作()h后,应停
Theoncebarrenhillsidesarenowgoodf
计算机辅助面访调查所用的软件系统一般包括( )四个子系统。A.问卷设计系统
人在每一瞬间,将心理活动选择了某些对象而忽略了另一些对象。这一特点指的是注意的(
期货投机者,按交易主体划分,可以分为( )。A.机构投机者 B.公共部门投资者
有限责任公司某股东欲转让出资,于2012年12月15日向其他股东发出书面转让通知
根据现行规定,因病假、停工学习等原因,按计时工资标准或计时工资标准的一定比例支付
最新回复
(
0
)