( ( During anaphase ) ( , ( ( ( ( ( sister chromatids ) separate ) and ) ( ( the centromeres ) divide ) ) . ) ) )
(ROOT (S (PP (IN During) (NP (NN anaphase))) (, ,) (S (NP (NN sister) (NNS chromatids)) (VP (VBP separate))) (CC and) (S (NP (DT the) (NNS centromeres)) (VP (VBP divide))) (. .)))
During anaphase , sister chromatids separate and the centromeres divide.
(ROOT (S (PP (IN During) (NP (DT the) (JJ anaphase) (NN phase))) (, ,) (S (NP (NN sister) (NNS chromatids)) (VP (VBP separate))) (CC and) (S (NP (DT the) (NNS centromeres)) (VP (VBP divide))) (. .)))