( ( The benthos ) ( ( is ( ( made up ) ( of ( ( marine organisms ) ( that ( live ( ( ( on or ) near ) ( the ( sea floor ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS benthos)) (VP (VBZ is) (VP (VBN made) (PRT (RP up)) (PP (IN of) (NP (NP (JJ marine) (NNS organisms)) (SBAR (WHNP (WDT that)) (S (VP (VBP live) (PP (IN on) (CC or) (IN near) (NP (DT the) (NN sea) (NN floor)))))))))) (. .)))
The benthos is made up of marine organisms that live on or near 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.