( ( Their ( tautomeric equilibria ) ) ( ( might ( be ( responsible ( for ( ( the ( spontaneous mutations ) ) ( in DNA ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP$ Their) (JJ tautomeric) (NN equilibria)) (VP (MD might) (VP (VB be) (ADJP (JJ responsible) (PP (IN for) (NP (NP (DT the) (JJ spontaneous) (NNS mutations)) (PP (IN in) (NP (NNP DNA)))))))) (. .)))
Their tautomeric equilibria might be responsible for the spontaneous mutations in DNA.
(ROOT (S (NP (NNP Induced) (CC or) (NNP spontaneous)) (VP (VBP are) (NP (NP (DT the) (CD two) (NNS methods)) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (NNS mutations)) (VP (VBP arise) (PP (IN in) (NP (NN dna)))))))) (. .)))