( ( ( ( Folding ( is complete ) ) and ) ( ( the embryo ) ( ( ( ( is now ) three-dimensional ) and ) ( ( is completely ) ( enclosed ( in ( the ( amniotic sac ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (NNP Folding)) (VP (VBZ is) (ADJP (JJ complete)))) (CC and) (S (NP (DT the) (NN embryo)) (VP (VP (VBZ is) (ADVP (RB now)) (ADJP (JJ three-dimensional))) (CC and) (VP (VBZ is) (ADVP (RB completely)) (VP (VBN enclosed) (PP (IN in) (NP (DT the) (JJ amniotic) (NN sac))))))) (. .)))
Folding is complete and the embryo is now three-dimensional and is completely enclosed in the amniotic sac.
(ROOT (S (NP (NP (DT The) (JJ amniotic) (NN sac)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBD was) (VP (VBG sitting) (PP (IN on) (NP (NP (NN top)) (PP (IN of) (NP (DT the) (JJ flat) (NN embryo))))))))) (, ,)) (VP (VBZ envelops) (NP (DT the) (NN embryo)) (SBAR (IN as) (S (NP (PRP it)) (VP (VBZ folds))))) (. .)))