( ( When ( ( the eggs ) ( become fertilized ) ) ) ( they ( ( develop ( into zygotes ) ) . ) ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (DT the) (NNS eggs)) (VP (VBP become) (S (VP (VBN fertilized)))))) (NP (PRP they)) (VP (VBP develop) (PP (IN into) (NP (NNS zygotes)))) (. .)))
When the eggs become fertilized they develop into zygotes.
(ROOT (S (NP (NP (DT The) (VBN fertilized) (NN egg)) (SBAR (WHNP (WDT that)) (S (ADVP (RB sexually)) (VP (VBG reproducing) (S (NP (NNS organisms)) (VP (VB begin) (NP (NN life)) (SBAR (IN as) (S (VP (VBZ is) (VP (VBN known) (PP (IN as) (NP (DT a) (-LRB- -LRB-) (NN n) (-RRB- -RRB-))))))))))))) (VP (VBP zygote)) (. .)))