( Effects ( ( can ( ( occur metabolically ) ( at ( the ( cell ( or ( organ level ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNPS Effects)) (VP (MD can) (VP (VB occur) (ADVP (RB metabolically)) (PP (IN at) (NP (DT the) (NN cell) (CC or) (NN organ) (NN level))))) (. .)))
Effects can occur metabolically at the cell or organ level.
(ROOT (S (NP (DT A) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN cell)) (VP (VBZ is) (NP (NP (DT the) (JJS lowest) (NN level)) (PP (IN of) (NP (NN organism))) (SBAR (WHNP (WDT that)) (S (VP (MD can) (VP (VB perform) (NP (NP (DT all) (NNS activities)) (VP (VBN required) (PP (IN for) (NP (NN life))))))))))) (. .)))