Electronic Waste It has been
known since ancient times that certain plants regularly open their leaves in
daytime and close them at night. It was assumed which this
62. ______ periodic change was triggered by the alternating sunlight
and darkness. Such leaves stick to their daily routine even when keeping in
constant darkness. 63. ______ What is
circadian rhythm Many biological processes follow a 24-hours
64. ______ schedule. These cycles are called circadian
rhythms. These innate rhythms are governed by sophisticated chemical
mechanisms can be described as biological 65.
______ clocks. Such rhythms are important for humans too! We sleep through
most of the hours of darkness and are awaken through most of the hours of
66. ______ daylight. Body
temperature increases during the day and decreases during the night. The
secretion of various hormones that controls life’s processes rises
67. ______ and falls to a circadian rhythm. How does
this relate to health Circadian rhythms are important for desirable
functioning of the processes vital to health. This is most
effectively illustrated and the normal circadian rhythms are disrupted by
lack of sleep or 68. ______ by crossing time miles. It may take
days or even hours for all the bodies 69.
______ circadian rhythms to read just appropriately. The turmoil (混乱) that
results from the readjustment process when time zones are crossed experienced
as the 70. ______ phenomenon of jet lag. This is also
experienced by people who do shift work. Understanding circadian rhythms may
be irrelevant to the understanding and 71.
______ treatment of disease. Therapy can be more effective and toxic effects
reduced when drugs are administered at carefully selected times of the
day.