( ( The benthos ) ( ( are ( ( organisms ( -LRB- ( ( ( animals and ) plants ) -RRB- ) ) ) ( that ( live ( on ( the ( sea floor ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS benthos)) (VP (VBP are) (NP (NP (NNS organisms)) (PRN (-LRB- -LRB-) (NP (NP (NNS animals)) (CC and) (NP (NNS plants))) (-RRB- -RRB-)) (SBAR (WHNP (WDT that)) (S (VP (VBP live) (PP (IN on) (NP (DT the) (NN sea) (NN floor)))))))) (. .)))
The benthos are organisms (animals and plants) that live on the sea floor.
(ROOT (S (NP (NP (VBG Living) (NNS things)) (PP (IN on) (NP (DT the) (NN ocean) (NN floor)))) (VP (VBP are) (VP (VBN known) (PP (IN as) (NP (NNS benthos))))) (. .)))
Living things on the ocean floor are known as benthos.