( ( ( ( Passive transpont ) - ) ( ( exchange ( of ( materials ( across ( the ( cell membrane ) ) ) ) ) ) ( ( in which ) ( ( the cell ) ( ( does not ) ( expend energy ) ) ) ) ) ) . )
(ROOT (NP (NP (NNP Passive) (NNP transpont)) (: -) (NP (NP (NN exchange)) (PP (IN of) (NP (NP (NNS materials)) (PP (IN across) (NP (DT the) (NN cell) (NN membrane))))) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (DT the) (NN cell)) (VP (VBZ does) (RB not) (VP (VB expend) (NP (NN energy))))))) (. .)))
Passive transpont- exchange of materials across the cell membrane in which the cell does not expend energy.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NNS substances)) (VP (VBP pass) (PP (IN through) (NP (DT the) (NN cell) (NN membrane))) (PP (IN without) (S (VP (VBG needing) (NP (DT any) (NN energy)))))))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN called) (NP (JJ passive) (NN transport)))) (. .)))