( ( Organisms ( that ( ( do n't ) ( produce ( their ( own energy ) ) ) ) ) ) ( ( are ( called heterotrophs ) ) . ) )
(ROOT (S (NP (NP (NNS Organisms)) (SBAR (WHNP (WDT that)) (S (VP (VBP do) (RB n't) (VP (VB produce) (NP (PRP$ their) (JJ own) (NN energy))))))) (VP (VBP are) (VP (VBN called) (NP (NNS heterotrophs)))) (. .)))
Organisms that don't produce their own energy are called heterotrophs.
(ROOT (S (NP (NNS Animals)) (VP (MD can) (RB not) (VP (VB produce) (NP (PRP$ their) (JJ own) (NN food)) (S (VP (VBG making) (S (NP (PRP them)) (ADJP (JJ heterotrophs)))))))))