( Protists ( ( are ( ( eukaryotes , ) ( organisms ( with ( organized nuclei ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Protists)) (VP (VBP are) (NP (NP (NNS eukaryotes)) (, ,) (NP (NP (NNS organisms)) (PP (IN with) (NP (VBN organized) (NNS nuclei)))))) (. .)))
Protists are eukaryotes, organisms with organized nuclei.
(ROOT (S (NP (JJ Many) (NNS scientists)) (VP (VBP think) (SBAR (S (NP (NNS protists)) (VP (VBP are) (NP (DT the) (JJS oldest) (NNS eukaryotes)))))) (. .)))