( ( Animal cells ) ( ( lack ( ( ( cell ( ( walls and ) chloroplasts ) ) , ) ( which ( are ( present ( in ( most plants ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Animal) (NNS cells)) (VP (VBP lack) (NP (NP (NN cell) (NNS walls) (CC and) (NNS chloroplasts)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (ADJP (JJ present) (PP (IN in) (NP (JJS most) (NNS plants))))))))) (. .)))
Animal cells lack cell walls and chloroplasts, which are present in most plants.
(ROOT (S (NP (DT A) (NN cell) (NN wall)) (VP (VBZ is) (VP (VBN found) (PP (PP (IN in) (NP (DT a) (NN plant) (NN cell))) (CONJP (CC but) (RB not)) (PP (IN in) (NP (DT an) (NN animal) (NN cell)))))) (. .)))
A cell wall is found in a plant cell but not in an animal cell.