( ( Animals ( are heterotrophs ) ) ( , ( they ( ( must ( ( ( absorb nutrients ) or ) ( ingest ( food sources ) ) ) ) . ) ) ) )
(ROOT (S (S (NP (NNS Animals)) (VP (VBP are) (ADJP (JJ heterotrophs)))) (, ,) (NP (PRP they)) (VP (MD must) (VP (VP (VB absorb) (NP (NNS nutrients))) (CC or) (VP (VB ingest) (NP (NN food) (NNS sources))))) (. .)))
Animals are heterotrophs , they must absorb nutrients or ingest food sources.
(ROOT (S (SBAR (IN Because) (S (NP (DT all) (NNS animals)) (VP (VBP require) (NP (NP (DT an) (JJ external) (NN source)) (PP (IN of) (NP (NN food))))))) (, ,) (NP (PRP they)) (VP (VBP are) (VP (VBN called) (S (ADJP (JJ heterotrophic))))) (. .)))