( ( An organ ) ( ( is ( ( a structure ) ( composed ( of ( ( ( ( at least ) two ) ( tissues types ) ) ( that ( performs ( ( a ( specific function ) ) ( for ( the body ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT An) (NN organ)) (VP (VBZ is) (NP (NP (DT a) (NN structure)) (VP (VBN composed) (PP (IN of) (NP (NP (QP (IN at) (JJS least) (CD two)) (JJ tissues) (NNS types)) (SBAR (WHNP (WDT that)) (S (VP (VBZ performs) (NP (NP (DT a) (JJ specific) (NN function)) (PP (IN for) (NP (DT the) (NN body)))))))))))) (. .)))
An organ is a structure composed of at least two tissues types that performs a specific function for the body.
(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))) (. .)))