( ( Their organization ) ( ( ( is ( at ( the ( cellular level ) ) ) ) ( as ( they ( lack ( ( any type ) ( of tissue ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP$ Their) (NN organization)) (VP (VBZ is) (PP (IN at) (NP (DT the) (JJ cellular) (NN level))) (SBAR (IN as) (S (NP (PRP they)) (VP (VBP lack) (NP (NP (DT any) (NN type)) (PP (IN of) (NP (NN tissue)))))))) (. .)))
Their organization is at the cellular level as they lack any type of tissue.
(ROOT (S (NP (NNS Roundworms)) (VP (VBP exemplify) (NP (NP (JJ organ-level) (NN organization)) (, ,) (SBAR (WHADVP (WRB where)) (S (NP (NP (QP (CD two) (CC or) (JJR more)) (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 particular) (NN function)) (PP (IN as) (NP (DT an) (NN organ))))))))))) (. .)))