( ( During ( ( mitosis or ) meiosis ) ) ( , ( ( the ( spindle checkpoint ) ) ( ( ( prevents ( anaphase onset ) ) ( until ( ( all chromosomes ) ( ( are properly ) ( attached ( to ( the spindle ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN During) (NP (NNS mitosis) (CC or) (NNS meiosis))) (, ,) (NP (DT the) (JJ spindle) (NN checkpoint)) (VP (VBZ prevents) (NP (JJ anaphase) (NN onset)) (SBAR (IN until) (S (NP (DT all) (NNS chromosomes)) (VP (VBP are) (ADVP (RB properly)) (VP (VBN attached) (PP (TO to) (NP (DT the) (NN spindle)))))))) (. .)))
During mitosis or meiosis, the spindle checkpoint prevents anaphase onset until all chromosomes are properly attached to the spindle.
(ROOT (S (NP (JJ Spindle) (NNS fibers)) (VP (VBP pull) (NP (VBN linked) (NNS chromosomes)) (PP (ADVP (RB apart)) (IN in) (NP (JJ anaphase) (NN i.))))))