( Roundworms ( ( have ( ( ( organ-level organization ) , ) ( ( in which ) ( ( ( ( ( two or ) more ) types ) ( of tissues ) ) ( ( work together ) ( to ( ( perform ( a ( particular function ) ) ) ( as ( an organ ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Roundworms)) (VP (VBP have) (NP (NP (JJ organ-level) (NN organization)) (, ,) (SBAR (WHPP (IN in) (WHNP (WDT which))) (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))))))))))) (. .)))
Roundworms have organ-level organization, in which two or more types of tissues work together to   perform a particular function as an organ.
(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))))))))))) (. .)))