( ( The embryo ) ( ( ( is now ) ( called ( a blastocyst ) ) ) . ) )
(ROOT (S (NP (DT The) (NN embryo)) (VP (VBZ is) (ADVP (RB now)) (VP (VBN called) (NP (DT a) (NN blastocyst)))) (. .)))
The embryo is now called a blastocyst.
(ROOT (S (PP (IN After) (NP (NN implantation))) (, ,) (NP (DT the) (NN blastocyst)) (VP (VBZ is) (VP (VBN called) (NP (DT an) (NN embryo)))) (. .)))