( ( The prostate ) ( ( is ( ( ( a ( small gland ) ) ( -LRB- ( ( about ( ( the size ) ( of ( a walnut ) ) ) ) -RRB- ) ) ) ( of ( ( the ( male ( reproductive system ) ) ) ( that ( is ( responsible ( for ( producing ( ( semen , ) ( ( the fluid ) ( that ( carries sperm ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN prostate)) (VP (VBZ is) (NP (NP (DT a) (JJ small) (NN gland)) (PRN (-LRB- -LRB-) (PP (IN about) (NP (NP (DT the) (NN size)) (PP (IN of) (NP (DT a) (NN walnut))))) (-RRB- -RRB-)) (PP (IN of) (NP (NP (DT the) (JJ male) (JJ reproductive) (NN system)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (ADJP (JJ responsible) (PP (IN for) (S (VP (VBG producing) (NP (NP (NN semen)) (, ,) (NP (NP (DT the) (NN fluid)) (SBAR (WHNP (WDT that)) (S (VP (VBZ carries) (NP (NN sperm)))))))))))))))))) (. .)))
The prostate is a small gland (about the size of a walnut) of the male reproductive system that is responsible for producing semen, the fluid that carries sperm.
(ROOT (S (NP (DT The) (NN prostate) (NN gland)) (VP (VBZ secretes) (NP (NP (DT a) (NN fluid)) (SBAR (WHNP (WDT that)) (S (VP (VBZ mixes) (PP (IN with) (NP (NN sperm))) (S (VP (TO to) (VP (VB help) (NP (NN form) (NN semen)))))))))) (. .)))