( ( The nucleus ) ( ( is ( bounded ( by ( ( ( ( ( a ( double membrane ) ) , ) ( the ( nuclear envelope ) ) ) or ) ( nuclear membrane ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN nucleus)) (VP (VBZ is) (VP (VBN bounded) (PP (IN by) (NP (NP (DT a) (JJ double) (NN membrane)) (, ,) (NP (DT the) (JJ nuclear) (NN envelope)) (CC or) (NP (JJ nuclear) (NNS membrane)))))) (. .)))
The nucleus is bounded by a double membrane, the nuclear envelope or nuclear membrane.
(ROOT (S (NP (NNP Nuclear) (NNP enevelope)) (VP (VBZ is) (NP (NP (DT a) (JJ double) (NN membrane)) (PP (IN of) (NP (NP (DT the) (NN nucleus)) (SBAR (WHNP (WDT that)) (S (VP (VBZ encloses) (NP (DT the) (JJ genetic) (NN material))))))))) (. .)))