( ( DNA replication ) ( ( occurs ( during ( this ( S ( ( -LRB- ( synthesis -RRB- ) ) phase ) ) ) ) ) . ) )
(ROOT (S (NP (NNP DNA) (NNP replication)) (VP (VBZ occurs) (PP (IN during) (NP (DT this) (NNP S) (PRN (-LRB- -LRB-) (NP (NN synthesis)) (-RRB- -RRB-)) (NN phase)))) (. .)))
DNA replication occurs during this S (synthesis) phase.
(ROOT (S (PP (IN During) (NP (NP (DT the) (NN synthesis) (NN phase)) (PP (IN in) (NP (DT the) (NN cell) (NN cycle))))) (, ,) (NP (NN dna) (NN replication)) (VP (VBZ occurs)) (. .)))