( ( ( ( ( One type ) , ) ( sexual reproduction ) ) , ) ( ( requires ( ( ( ( ( the union ) ( of ( ( ( male and ) female ) ( sex cells ) ) ) ) , ) or ) ( ( gametes ( -LRB- ( ( ( sperm and ) eggs ) -RRB- ) ) ) ( in ( ( the formation ) ( of ( a ( new organism ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (CD One) (NN type)) (, ,) (NP (JJ sexual) (NN reproduction)) (, ,)) (VP (VBZ requires) (NP (NP (NP (DT the) (NN union)) (PP (IN of) (NP (ADJP (NN male) (CC and) (JJ female)) (NN sex) (NNS cells)))) (, ,) (CC or) (NP (NP (NP (NNS gametes)) (PRN (-LRB- -LRB-) (NP (NN sperm) (CC and) (NNS eggs)) (-RRB- -RRB-))) (PP (IN in) (NP (NP (DT the) (NN formation)) (PP (IN of) (NP (DT a) (JJ new) (NN organism)))))))) (. .)))
One type, sexual reproduction,  requires the union of male and female sex cells, or gametes (sperm and eggs) in the formation of a new organism.
(ROOT (S (NP (NP (JJ Sexual) (NN reproduction)) (, ,) (PP (IN in) (NP (NN general))) (, ,)) (VP (VBZ relies) (PP (IN on) (NP (NP (NNS sets)) (PP (IN of) (NP (NP (NNS cells)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (NP (NP (NNS precursors)) (PP (IN for) (NP (NNS eggs) (CC and) (NN sperm)))))))))))) (. .)))