( ( An ORGAN ) ( ( is ( ( a ( discrete structure ) ) ( that ( ( ( performs ( specific functions ) ) and ) ( is ( composed ( of ( ( ( at least ) 2 ) ( tissue types ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT An) (NN ORGAN)) (VP (VBZ is) (NP (NP (DT a) (JJ discrete) (NN structure)) (SBAR (WHNP (WDT that)) (S (VP (VP (VBZ performs) (NP (JJ specific) (NNS functions))) (CC and) (VP (VBZ is) (VP (VBN composed) (PP (IN of) (NP (QP (IN at) (JJS least) (CD 2)) (NN tissue) (NNS types)))))))))) (. .)))
An ORGAN is a discrete structure that performs specific functions and is composed of at least 2 tissue types.
(ROOT (S (NP (DT A) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN organ)) (VP (VBZ is) (NP (NP (DT a) (NN structure)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN composed) (PP (IN of) (NP (NP (QP (CD one) (CC or) (JJR more)) (NNS types)) (PP (IN of) (NP (NNS tissues))))))))))) (. .)))
A(n) organ is a structure that is composed of one or more types of tissues.