( ( epithelial tissue ) ( ( ( Cells ( in animals ) ) ( ( ( ( that ( are ( closely ( packed ( in ( either ( single ( or ( multiple layers ) ) ) ) ) ) ) ) ) , ) and ) ( which ( cover ( ( both ( internal ( and ( external surfaces ) ) ) ) ( of ( the ( animal body ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ epithelial) (NN tissue)) (VP (VBZ Cells) (PP (IN in) (NP (NNS animals))) (SBAR (SBAR (WHNP (WDT that)) (S (VP (VBP are) (ADJP (RB closely) (VBN packed) (PP (IN in) (NP (DT either) (JJ single) (CC or) (JJ multiple) (NNS layers))))))) (, ,) (CC and) (SBAR (WHNP (WDT which)) (S (VP (VBP cover) (NP (NP (DT both) (JJ internal) (CC and) (JJ external) (NNS surfaces)) (PP (IN of) (NP (DT the) (NN animal) (NN body))))))))) (. .)))
epithelial tissue Cells in animals that are closely packed in either single or multiple layers, and which cover both internal and external surfaces of the animal body.
(ROOT (S (NP (NNP Epithelial) (. ?) (NNP tissue)) (VP (VBZ consists) (PP (IN of) (NP (NP (NNS cells)) (SBAR (WHNP (WHNP (WDT that) (NN cover)) (NP (JJ inner) (CC and) (JJ outer) (NN body))) (S (VP (VBZ surfaces))))))) (. .)))