( ( Hearts Fish ) ( ( have ( ( a ( two-chambered heart ) ) ( while ( ( ( mammals and ) birds ) ( have ( four ( chambered hearts ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Hearts) (NNP Fish)) (VP (VBP have) (NP (NP (DT a) (JJ two-chambered) (NN heart)) (SBAR (IN while) (S (NP (NNS mammals) (CC and) (NNS birds)) (VP (VBP have) (NP (CD four) (JJ chambered) (NNS hearts))))))) (. .)))
Hearts Fish have a two-chambered heart while mammals and birds have four chambered hearts .
(ROOT (S (PP (IN Like) (NP (NP (DT all) (NNS tetrapods)) (PP (IN except) (NP (NNS birds) (CC and) (NNS mammals))))) (, ,) (NP (NNS frogs)) (VP (VBP possess) (NP (NP (DT a) (NN heart)) (PP (IN with) (NP (CD three) (NNS chambers))))) (. .)))