( They ( ( ( go through ) ( only ( ( a ( three ( stage ( life cycle ) ) ) ) ( ( ( called ( gradual metamorphosis ) ) , ) ( while ( ( many insects ) ( have ( ( a ( four ( stage ( life cycle ) ) ) ) ( -LRB- ( ( complete metamorphosis ) -RRB- ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP go) (PRT (RP through)) (SBAR (RB only) (S (NP (DT a) (CD three) (NN stage) (NN life) (NN cycle)) (VP (VBD called) (NP (JJ gradual) (NNS metamorphosis)) (, ,) (SBAR (IN while) (S (NP (JJ many) (NNS insects)) (VP (VBP have) (NP (NP (DT a) (CD four) (NN stage) (NN life) (NN cycle)) (PRN (-LRB- -LRB-) (NP (JJ complete) (NNS metamorphosis)) (-RRB- -RRB-)))))))))) (. .)))
They go through only a three stage life cycle called gradual metamorphosis, while many insects have a four stage life cycle (complete metamorphosis).
(ROOT (S (NP (NNS Cells)) (VP (VBP have) (NP (CD four) (NNS cycles))) (. .)))