( ( ( ( ( Deletions ( remove nucleotides ) ) , ) and ) ( insertions ( add nucleotides ) ) ) . )
(ROOT (S (S (NP (NNS Deletions)) (VP (VB remove) (NP (NNS nucleotides)))) (, ,) (CC and) (S (NP (NNS insertions)) (VP (VBP add) (NP (NNS nucleotides)))) (. .)))
Deletions remove nucleotides, and insertions add nucleotides.
(ROOT (S (ADVP (RB Deletions)) (VP (VB remove) (NP (NP (QP (CD one) (CC or) (JJR more)) (NNS nucleotides)) (PP (IN from) (NP (DT the) (NN dna)))))))