Biological clock (Biological clock) or a clock "that controls the operation of the various systems in the body, caused by a 24-hour response to solar temperatures and darkness.
The biological clock (Biological clock) or clock "that controls the functions of the various systems in the body over 24 hours by the response to sunlight, temperature and darkness.
Biological Biological clock) or the clock of life "that control the operation of various systems in the body throughout the 24 hours. Caused by the response to sunlight, temperature, and the darkness.