( ( ( An ( amphibian 's ) ) heart ) ( ( has ( three chambers ) ) . ) )
(ROOT (S (NP (NP (DT An) (NN amphibian) (POS 's)) (NN heart)) (VP (VBZ has) (NP (CD three) (NNS chambers))) (. .)))
An amphibian's heart has three chambers.
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD three) (NNS chambers)) (PP (IN in) (NP (DT a) (JJ reptiles) (NN heart))))) (. .)))