( ( If ( ( ( ( you ( ( took ( the DNA ) ) ( from ( ( ( a ( single ( human cell ) ) ) , ) ( that ( ( is , ) ( the ( four ( long molecules ) ) ) ) ) ) ) ) ) , ) and ) ( you ( put ( them ( end ( on end ) ) ) ) ) ) ) ( , ( you ( ( couldn ( t ( ( see them ) ( because ( they ( d ( ( be ( ( only two-billionths ) ( of ( a meter ) ) ) ) across ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN If) (S (S (NP (PRP you)) (VP (VBD took) (NP (DT the) (NN DNA)) (PP (IN from) (NP (NP (DT a) (JJ single) (JJ human) (NN cell)) (, ,) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (, ,) (NP (DT the) (CD four) (JJ long) (NNS molecules))))))))) (, ,) (CC and) (S (NP (PRP you)) (VP (VBD put) (S (NP (PRP them)) (VP (VB end) (PP (IN on) (NP (NN end))))))))) (, ,) (NP (PRP you)) (VP (VBP couldn) (S (NP (NN t)) (VP (VB see) (NP (PRP them)) (SBAR (IN because) (S (NP (PRP they)) (ADVP (RB d)) (VP (VB be) (NP (NP (JJ only) (NNS two-billionths)) (PP (IN of) (NP (DT a) (NN meter)))) (PP (IN across)))))))) (. .)))
If you took the DNA from a single human cell, that is, the four long molecules, and you put them end on end, you couldn t see them because they d be only two-billionths of a meter across.
(ROOT (S (SBAR (IN If) (S (NP (NP (DT the) (NN dna)) (PP (IN from) (NP (NP (DT all) (CD 46) (NNS chromosomes)) (PP (IN in) (NP (DT a) (JJ human) (NN cell) (NN nucleus)))))) (VP (VBD was) (VP (VBN laid) (PRT (RP out)) (NP (NN end)) (S (VP (TO to) (VP (VB end)))))))) (, ,) (NP (PRP it)) (VP (MD would) (VP (VB measure) (ADVP (NP (QP (RB approximately) (CD two)) (NNS meters)) (RB long)))) (. .)))
If the dna from all 46 chromosomes in a human cell nucleus was laid out end to end, it would measure approximately two meters long.