( ( If ( ( ( the chromosomes ) ( in ( a ( single cell ) ) ) ) ( were ( ( ( stretched out ) and ) ( ( laid end ) ( to end ) ) ) ) ) ) ( , ( ( the DNA ) ( ( would ( be ( ( two meters ) long ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN If) (S (NP (NP (DT the) (NNS chromosomes)) (PP (IN in) (NP (DT a) (JJ single) (NN cell)))) (VP (VBD were) (VP (VP (VBN stretched) (PRT (RP out))) (CC and) (VP (VBN laid) (NP (NN end)) (S (VP (TO to) (VP (VB end))))))))) (, ,) (NP (DT the) (NN DNA)) (VP (MD would) (VP (VB be) (ADJP (NP (CD two) (NNS meters)) (JJ long)))) (. .)))
If the chromosomes in a single cell were stretched out and laid end to end, the DNA would be two meters long.
(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.