( ( All ( the ( elemental oxygen ) ) ) ( ( now ( in ( ( the ( earth 's ) ) atmosphere ) ) ) ( ( was ( ( put there ) ( by ( photosynthetic ( ( plants and ) bacteria ) ) ) ) ) . ) ) )
(ROOT (S (NP (PDT All) (DT the) (JJ elemental) (NN oxygen)) (ADVP (RB now) (PP (IN in) (NP (NP (DT the) (NN earth) (POS 's)) (NN atmosphere)))) (VP (VBD was) (VP (VBN put) (ADVP (RB there)) (PP (IN by) (NP (JJ photosynthetic) (NNS plants) (CC and) (NNS bacteria))))) (. .)))
All the elemental oxygen now in the earth's atmosphere was put there by photosynthetic plants and bacteria.
(ROOT (S (PP (IN On) (NP (DT a) (JJ global) (NN scale))) (, ,) (NP (NP (NNS plants)) (CC and) (NP (JJ other) (JJ photosynthetic) (NNS organisms))) (VP (VBP have) (VP (VBN generated) (NP (NP (DT all)) (PP (IN of) (NP (NP (DT the) (NN oxygen)) (PP (IN in) (NP (DT the) (NN air)))))))) (. .)))
On a global scale, plants and other photosynthetic organisms have generated all of the oxygen in the air.