( ( ( ( Types ( of reproduction ) ) -- ) ( ( sexual , ) asexual ) ) . )
(ROOT (NP (NP (NP (NNS Types)) (PP (IN of) (NP (NN reproduction)))) (: --) (NP (NP (JJ sexual)) (, ,) (NP (NN asexual))) (. .)))
Types of reproduction---sexual, asexual.
(ROOT (S (NP (JJ Sexual) (NN reproduction)) (ADVP (RB usually)) (VP (VBP occur) (PP (IN during) (NP (NP (NNS times)) (PP (IN of) (NP (JJ environmental) (NN stress)))))) (. .)))