( ( ( ( Circadian rhythm ) - ) ( cycles ( that ( fluctuate ( on ( a ( daily basis ) ) ) ) ) ) ) . )
(ROOT (NP (NP (NN Circadian) (NN rhythm)) (: -) (NP (NP (NNS cycles)) (SBAR (WHNP (WDT that)) (S (VP (VBP fluctuate) (PP (IN on) (NP (DT a) (JJ daily) (NN basis))))))) (. .)))
Circadian rhythm -cycles that fluctuate on a daily basis.
(ROOT (S (NP (NN Circadian) (NNS rhythms)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (NP (JJ daily) (NNS cycles)) (PP (IN of) (NP (NN behavior)))))) (, ,) (PP (IN like) (NP (DT the) (JJ sleep-wake) (NN cycle)))) (. .)))