( Stomata ( ( ( are ( used ( by ( ( plants ( to ( facilitate ( gas exchange ) ) ) ) . ) ) ) ) ( Why ( ( are ( they absent ) ) ( in charophytes ) ) ) ) ? ) )
(ROOT (S (NP (NNP Stomata)) (VP (VBP are) (ADJP (VBN used) (PP (IN by) (FRAG (NP (NP (NNS plants)) (SBAR (S (VP (TO to) (VP (VB facilitate) (NP (NN gas) (NN exchange)))))) (. .))))) (SBAR (WHADVP (WRB Why)) (S (VP (VBP are) (ADJP (NP (PRP they)) (JJ absent)) (PP (IN in) (NP (NNS charophytes))))))) (. ?)))
Stomata are used by plants to facilitate gas exchange. Why are they absent in charophytes?
(ROOT (S (NP (NNS Charophytes)) (VP (VBP are) (NP (NP (DT the) (JJS closest) (VBG living) (NNS relations)) (PP (TO to) (NP (NN land) (NNS plants))))) (. .)))