( Phytoplankton ( ( ( make ( their food ) ) ( through photosynthesis ) ) . ) )
(ROOT (S (NP (NNP Phytoplankton)) (VP (VBP make) (NP (PRP$ their) (NN food)) (PP (IN through) (NP (NN photosynthesis)))) (. .)))
Phytoplankton make their food through photosynthesis.
(ROOT (S (NP (NNP Phytoplankton)) (VP (VBP make) (NP (NP (NN food)) (PP (IN via) (NP (NN photosynthesis))))) (. .)))