( This ( ( means ( that ( they ( ( ( are single-celled ) , ) ( prokaryotic ( ( -LRB- ( simple -RRB- ) ) organisms ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ means) (SBAR (IN that) (S (NP (PRP they)) (VP (VP (VBP are) (ADJP (JJ single-celled))) (, ,) (NP (JJ prokaryotic) (PRN (-LRB- -LRB-) (ADJP (JJ simple)) (-RRB- -RRB-)) (NNS organisms)))))) (. .)))
This means that they are single-celled, prokaryotic (simple) organisms.
(ROOT (S (NP (JJ Single-celled) (NNS organisms)) (VP (VBP are) (ADJP (JJ prokaryotes))) (. .)))