( ( Circadian rhythms ) ( ( ( ( ( are , ) ( in part ) ) , ) ( tied ( to ( ( the ( 24-hour cycle ) ) ( of ( ( ( ( ( the ( Earth 's ) ) rotation ) and ) ( ( the amount ) ( of daylight ) ) ) ( ( to which ) ( you ( 're exposed ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NN Circadian) (NNS rhythms)) (VP (VBP are) (, ,) (PP (IN in) (NP (NN part))) (, ,) (S (VP (VBN tied) (PP (TO to) (NP (NP (DT the) (JJ 24-hour) (NN cycle)) (PP (IN of) (NP (NP (NP (DT the) (NN Earth) (POS 's)) (NN rotation)) (CC and) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NN daylight)))) (SBAR (WHPP (TO to) (WHNP (WDT which))) (S (NP (PRP you)) (VP (VBP 're) (VP (VBN exposed)))))))))))) (. .)))
Circadian rhythms are, in part, tied to the 24-hour cycle of the Earth's rotation and the amount of daylight to which you're exposed.
(ROOT (S (NP (NP (JJ Regular) (NNS changes)) (PP (IN in) (NP (NN biology) (CC or) (NN behavior))) (SBAR (WHNP (WDT that)) (S (VP (VBP occur) (PP (IN in) (NP (DT a) (CD 24) (NN hour) (NN cycle))))))) (VP (VBP are) (NP (NP (NN part)) (PP (IN of) (NP (DT the) (NN circadian) (NN rhythm))))) (. .)))