( ( ( ( ( ( Gene expression ) , ) or ) ( ( the synthesis ) ( of ( specific proteins ) ) ) ) , ) ( ( is ( ( ( ( regulated mainly ) ( at ( ( the level ) ( of transcription ) ) ) ) , ) ( ( the process ) ( of ( making ( ( ( RNA copies ) ( of ( the ( DNA sequences ) ) ) ) ( that ( comprise ( the genes ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Gene) (NN expression)) (, ,) (CC or) (NP (NP (DT the) (NN synthesis)) (PP (IN of) (NP (JJ specific) (NNS proteins)))) (, ,)) (VP (VBZ is) (VP (VBN regulated) (ADVP (RB mainly)) (PP (IN at) (NP (NP (DT the) (NN level)) (PP (IN of) (NP (NN transcription))))) (, ,) (NP (NP (DT the) (NN process)) (PP (IN of) (S (VP (VBG making) (NP (NP (NNP RNA) (NNS copies)) (PP (IN of) (NP (DT the) (NN DNA) (NNS sequences))) (SBAR (WHNP (WDT that)) (S (VP (VBP comprise) (NP (DT the) (NNS genes)))))))))))) (. .)))
Gene expression, or the synthesis of specific proteins, is regulated mainly at the level of transcription, the process of making RNA copies of the DNA sequences that comprise the genes.
(ROOT (S (NP (NNP Gene) (NN expression) (CC and) (NN protein) (NNS synthesis)) (VP (VBP are) (ADVP (RB usually)) (VP (VBN considered) (NP (DT the) (JJ same) (JJ molecular) (NN process)))) (. .)))