生物钟又称生理钟。它是生物体内的一种无形的“时钟”，实际上是生物体生命活动的内在节律性，它是由生物体内的时间结构序所决定-Also known physiological circadian clock. It is an invisible vivo " clock" is actually inherent biological rhythm of life activities, it is by the time structure of in vivo determi