You are looking at 1-20 of 321 entries for:
- All: biological clock x
Did you mean Biological clocks, biological clock Biological clocks, biological clock
biological clock
1. any mechanism that allows expression of specific genes at periodic intervals. 2. any physiological factor that regulates body rhythms. See clock mutants.
biological clock Quick reference
A Dictionary of Genetics (8 ed.)
... clock 1. any mechanism that allows expression of specific genes at periodic intervals. 2. any physiological factor that regulates body rhythms. See clock mutants...
biological clock n. Quick reference
A Dictionary of Psychology (4 ed.)
... clock n. Any mechanism or process responsible for a biological rhythm . See also pacemaker neuron , suprachiasmatic nucleus , telomere , Zeitgeber...
biological clock Reference library
Oxford Dictionary of Biochemistry and Molecular Biology (2 ed.)
... clock any biological mechanism that allows the expression of a certain biological structure (e.g. a gene) or a biological function (e.g. sleep) at periodic intervals. The term is also used colloquially to describe ageing, e.g. in respect to a woman's ability to bear a...
biological clock Quick reference
World Encyclopedia
... clock Internal system in organisms that relates behaviour to natural rhythms. Functions, such as growth, feeding, or reproduction, coincide with certain external events, including day and night, tides, and seasons. These ‘clocks’ seem to be set by environmental conditions, but if organisms are isolated from these conditions, they still function according to the usual...
biological clock Quick reference
A Dictionary of Biology (8 ed.)
...light and are degraded during the day. Hence, the biological clock is entrained to the day-night cycle. Although the clock proteins differ in different organisms, similar mechanisms have evolved independently in diverse organisms. In humans the central oscillator of the biological clock resides in the paired suprachiasmatic nuclei (SCN), lying above the optic chiasma deep within the brain. They receive input from the retina of the eyes to synchronize the ‘clock’ with the day-night cycle. Genes of the human ‘clock’ are also expressed cyclically in other tissues,...
biological clock Quick reference
A Dictionary of Zoology (5 ed.)
... clock An endogenous, physiological mechanism, whose exact nature has not been determined, that keeps time independently of external events, enabling organisms to determine and to respond to daily, lunar, seasonal, and other periodicities. Its existence has been inferred from the observation of organisms which retain rhythmic activity under constant conditions. See also circadian rhythm ....
biological clock Quick reference
A Dictionary of Ecology (5 ed.)
... clock An endogenous, physiological mechanism, whose exact nature has not been determined, that keeps time independently of external events, enabling organisms to determine and to respond to daily, lunar, seasonal, and other periodicities. Its existence has been inferred from the observation of organisms which retain rhythmic activity under constant conditions. US scientists Jeffrey Hall, Michael Rosbash and Michael Young won the 2017 Nobel Prize for physiology or medicine for their work on the body clock. See also circadian rhythm...
biological clock Reference library
Martin John Wells
The Oxford Companion to the Mind (2 ed.)
... clock . Anybody who has crossed the Atlantic in an aeroplane knows about ‘ jet lag ’. After a journey from London to New York it is difficult to stay awake, while after the return journey one tends to wake up late. Man's body is intolerant of changes in clock time and it takes several days to readjust to a new local time. The same is true of practically all other animals, not very surprisingly, because we all live on the same planet and experience the same 24-hour cycle as the earth rotates. Mice, birds, and men eat and sleep at particular times of...
biological clock Quick reference
A Dictionary of Animal Behaviour (2 ed.)
... clock A mechanism, internal to the animal, that has a rhythmic influence upon its physiology and behaviour, synchronizing them to cyclic changes in the environment. This is done in three main ways: (1) there may be a direct response to various changes in external (exogenous) geophysical stimuli; (2) there may be an internal (endogenous) rhythm that programs the animal's behaviour in synchrony with the exogenous temporal period, particularly a 24-hour or a 365-day period; or (3) the synchronization mechanism may be a combination of (1) and (2). An...
Biological clock Reference library
Brewer's Dictionary of Modern Phrase & Fable (2 ed.)
... clock . A supposed natural mechanism inside the body that controls the rhythm of the body's functions, whether they occur on a daily basis, such as sleeping, monthly, such as the menstrual cycle, or seasonally, such as the growth rate of children. The term is popularly misunderstood to denote the inexorable ‘ticking away’ of a woman's fertile years. See also Circadian rhythms . My biological clock is ticking so loud I'm nearly deafened by it. They search me going into planes. marian keyes : ‘Late Opening in the Last Chance Saloon’ ( 1997...
biological clock
Biological clocks Reference library
Magic Universe: A Grand Tour of Modern Science
...light levels their clocks run fast. They feel sleepy, wakeful or hungry prematurely, and their body temperatures vary with a faster cadence. The uncorrected biological clock gains by about an hour each day, ahead of events in the outside world. That is a sign that human beings evolved as creatures of the day. Getting up late was riskier than rising too soon. In mammals active at night, the clocks run slow when light levels don't vary, as if to avoid being spotted in the evening twilight. If you want to reset your clock, after working night shifts or travelling...
pacemaker neuron
circannual rhythm
