( ( If ( ( ( one or ) ( two ( base pairs ) ) ) ( are ( changed ( -LRB- ( mutated -RRB- ) ) ) ) ) ) ( , ( ( the embryo ) ( ( will ( fail ( to ( develop properly ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN If) (S (NP (NP (CD one)) (CC or) (NP (CD two) (NN base) (NNS pairs))) (VP (VBP are) (ADJP (VBN changed) (PRN (-LRB- -LRB-) (VP (VBN mutated)) (-RRB- -RRB-)))))) (, ,) (NP (DT the) (NN embryo)) (VP (MD will) (VP (VB fail) (S (VP (TO to) (VP (VB develop) (ADVP (RB properly))))))) (. .)))
If one or two            base pairs are changed (mutated), the embryo will fail to develop properly.
(ROOT (S (NP (NP (NNS Invertebrates)) (-LRB- -LRB-) (CC and) (NP (JJR higher) (NNS animals)) (-RRB- -RRB-)) (VP (MD can) (ADVP (RB also)) (VP (VB be) (VP (VBN placed) (PP (IN in) (NP (NP (CD one)) (PP (IN of) (NP (CD two) (NNS groups))))) (PP (VBN based) (PP (IN on) (SBAR (WHADVP (WRB how)) (S (NP (PRP they)) (VP (VBP develop) (PP (IN as) (NP (NNS embryos))))))))))) (. .)))
Invertebrates (and higher animals) can also be placed in one of two groups based on how they develop as embryos.