( Autotrophs ( ( can ( be ( ( photoautotrophs or ) chemoautotrophs ) ) ) . ) )
(ROOT (S (NP (NNS Autotrophs)) (VP (MD can) (VP (VB be) (NP (NNS photoautotrophs) (CC or) (NNS chemoautotrophs)))) (. .)))
Autotrophs can be photoautotrophs or chemoautotrophs.
(ROOT (S (NP (NNS Photoautotrophs) (CC and) (NNS chemoautotrophs)) (VP (VBP are) (NP (NP (CD two) (JJ basic) (NNS types)) (PP (IN of) (NP (NNS autotrophs))))) (. .)))