( Reproduction ( ( ( is usually ) ( sexual ( with ( separate sexes ) ) ) ) . ) )
(ROOT (S (NP (NNP Reproduction)) (VP (VBZ is) (ADVP (RB usually)) (ADJP (JJ sexual) (PP (IN with) (NP (JJ separate) (NNS sexes))))) (. .)))
Reproduction is  usually sexual with separate sexes.
(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)))))) (. .)))