( ( During ( ( ( the ( synthesis phase ) ) ( -LRB- ( S-phase -RRB- ) ) ) ( of ( the ( eukaryotic ( cell cycle ) ) ) ) ) ) ( , ( ( DNA replication ) ( occurs . ) ) ) )
(ROOT (S (PP (IN During) (NP (NP (NP (DT the) (NN synthesis) (NN phase)) (PRN (-LRB- -LRB-) (NP (NNP S-phase)) (-RRB- -RRB-))) (PP (IN of) (NP (DT the) (JJ eukaryotic) (NN cell) (NN cycle))))) (, ,) (NP (NNP DNA) (NNP replication)) (VP (VBZ occurs)) (. .)))
During the synthesis phase (S-phase) of the eukaryotic cell cycle, DNA replication occurs.
(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)) (. .)))