( They ( ( interfere ( with ( DNA replication ) ) ) ( by ( ( attacking ( DNA synthesis ) ) ( throughout ( the ( cell cycle ) ) ) ) ) ) )
(ROOT (S (NP (PRP They)) (VP (VBP interfere) (PP (IN with) (NP (NN DNA) (NN replication))) (PP (IN by) (S (VP (VBG attacking) (NP (NN DNA) (NN synthesis)) (PP (IN throughout) (NP (DT the) (NN cell) (NN cycle)))))))))
They interfere with DNA replication by attacking DNA synthesis throughout the cell cycle
(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)) (. .)))