( ( ( structure , ) ( ( ( interactions and ) functions ) ( of ( cell walls ) ) ) ) ; )
(ROOT (NP (NP (NN structure)) (, ,) (NP (NP (NNS interactions) (CC and) (NNS functions)) (PP (IN of) (NP (NN cell) (NNS walls)))) (: ;)))
structure, interactions and functions of cell walls;
(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))))) (. .)))