( Stomata ( ( are ( pores ( on ( ( the ( leaf epidermis ) ) ( ( through which ) ( ( ( gas exchange ) ( -LRB- ( ( ( ( carbon dioxide ) , ) ( oxygen ( and ( water vapor ) ) ) ) -RRB- ) ) ) ( takes place ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Stomata)) (VP (VBP are) (ADJP (JJ pores) (PP (IN on) (NP (NP (DT the) (NN leaf) (NNS epidermis)) (SBAR (WHPP (IN through) (WHNP (WDT which))) (S (NP (NP (NN gas) (NN exchange)) (PRN (-LRB- -LRB-) (NP (NN carbon) (NN dioxide)) (, ,) (NP (NN oxygen) (CC and) (NN water) (NN vapor)) (-RRB- -RRB-))) (VP (VBZ takes) (NP (NN place))))))))) (. .)))
Stomata are pores on the leaf epidermis through which gas exchange (carbon dioxide, oxygen and water vapor) takes place.
(ROOT (S (NP (NP (DT The) (NNS epidermis)) (PP (IN of) (NP (DT a) (NN leaf)))) (VP (VBZ contains) (NP (NP (NNS openings)) (VP (VBN known) (PP (IN as) (NP (NP (NN stomata)) (, ,) (SBAR (WHPP (IN through) (WHNP (WDT which))) (S (NP (NP (DT the) (NN exchange)) (PP (IN of) (NP (NNS gases)))) (VP (VBZ takes) (NP (NN place)))))))))) (. .)))