( ( ( Several types ) ( of tissue ) ) ( ( ( work together ) ( in ( ( the form ) ( of ( an ( organ ( to ( ( produce ( a ( particular function ) ) ) ( -LRB- ( ( such ( as ( ( the pumping ) ( of ( ( the blood ) ( ( ( ( by ( the heart ) ) , ) or ) ( as ( ( a barrier ) ( to ( ( the environment ) ( as ( the skin ) ) ) ) ) ) ) ) ) ) ) ) -RRB- ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (JJ Several) (NNS types)) (PP (IN of) (NP (NN tissue)))) (VP (VBP work) (ADVP (RB together)) (PP (IN in) (NP (NP (DT the) (NN form)) (PP (IN of) (NP (DT an) (NN organ) (S (VP (TO to) (VP (VB produce) (NP (DT a) (JJ particular) (NN function)) (PRN (-LRB- -LRB-) (PP (JJ such) (IN as) (NP (NP (DT the) (NN pumping)) (PP (IN of) (NP (NP (DT the) (NN blood)) (PP (PP (IN by) (NP (DT the) (NN heart))) (, ,) (CC or) (PP (IN as) (NP (NP (DT a) (NN barrier)) (PP (TO to) (NP (NP (DT the) (NN environment)) (PP (IN as) (NP (DT the) (NN skin)))))))))))) (-RRB- -RRB-)))))))))) (. .)))
Several types of tissue work together in the form of an organ to produce a particular function (such as the pumping of the blood by the heart, or as a barrier to the environment as the skin).
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NP (JJ different) (NNS types)) (PP (IN of) (NP (NNS tissues)))) (VP (VBP work) (ADVP (RB together)) (S (VP (TO to) (VP (VB perform) (NP (DT a) (JJ unique) (NN function)))))))) (, ,) (NP (PRP they)) (VP (VBP form) (NP (NN organ))) (. .)))