( ( ( ( ( ( Prokaryotic cells ) ( are ( surrounded ( by ( a membrane ) ) ) ) ) , ) but ) ( they ( contain ( ( ( ( ( no nucleus ) or ) ( ( other ( internal parts ) ) ( -LRB- ( organelles -RRB- ) ) ) ) , ) ( contrary ( to ( eukaryotic cells ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (JJ Prokaryotic) (NNS cells)) (VP (VBP are) (VP (VBN surrounded) (PP (IN by) (NP (DT a) (NN membrane)))))) (, ,) (CC but) (S (NP (PRP they)) (VP (VBP contain) (NP (NP (DT no) (NN nucleus)) (CC or) (NP (NP (JJ other) (JJ internal) (NNS parts)) (PRN (-LRB- -LRB-) (NP (NNS organelles)) (-RRB- -RRB-))) (, ,) (ADVP (JJ contrary) (PP (TO to) (NP (JJ eukaryotic) (NNS cells))))))) (. .)))
Prokaryotic cells are surrounded by a membrane, but they contain no nucleus or other internal parts (organelles), contrary to eukaryotic cells.
(ROOT (S (NP (DT The) (NN nucleus)) (VP (VP (VBZ is) (VP (VBN surrounded) (PP (IN by) (NP (DT a) (NN membrane))))) (CC and) (VP (VBZ holds) (NP (NP (DT the) (JJ genetic) (NN information)) (PP (IN for) (NP (DT the) (NN cell)))))) (. .)))