( ( Cell walls ) ( ( ( give ( plant cells ) ) ( their ( structural strength ) ) ) . ) )
(ROOT (S (NP (JJ Cell) (NNS walls)) (VP (VBP give) (NP (NN plant) (NNS cells)) (NP (PRP$ their) (JJ structural) (NN strength))) (. .)))
Cell walls give plant cells their structural strength.
(ROOT (S (NP (DT A) (NN cell) (NN wall)) (VP (VBZ is) (RB not) (ADJP (JJ present) (PP (IN in) (NP (NN animal) (NNS cells))))) (. .)))