( Histology ( ( involves ( both ( ( ( ( the examination ) ( of ( ( the characteristics ) ( of ( the ( four ( basic ( tissue types ) ) ) ) ) ) ) ) and ) ( ( the ( ( structure and ) organization ) ) ( of ( organs ( and ( organ systems ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Histology)) (VP (VBZ involves) (NP (PDT both) (NP (NP (DT the) (NN examination)) (PP (IN of) (NP (NP (DT the) (NNS characteristics)) (PP (IN of) (NP (DT the) (CD four) (JJ basic) (NN tissue) (NNS types)))))) (CC and) (NP (NP (DT the) (NN structure) (CC and) (NN organization)) (PP (IN of) (NP (NNS organs) (CC and) (NN organ) (NNS systems)))))) (. .)))
Histology involves both the examination of the characteristics of the four basic tissue types and the structure and organization of organs and organ systems.
(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.