( ( Plant cells ) ( ( have ( ( ( ( cell walls ) , ) not ) ( cell membranes ) ) ) . ) )
(ROOT (S (NP (NNP Plant) (NNS cells)) (VP (VBP have) (NP (NP (NN cell) (NNS walls)) (, ,) (RB not) (NP (NN cell) (NNS membranes)))) (. .)))
Plant cells have cell walls, not cell membranes.
(ROOT (S (NP (JJ Prokaryotic) (NNS cells)) (VP (VBP have) (NP (NP (DT a) (NN cell) (NN wall)) (PP (IN outside) (NP (PRP$ their) (NN plasma) (NN membrane))))) (. .)))