( ( The kidneys ) ( ( ( ( are ( where ( urine ( is formed ) ) ) ) , ) ( as ( ( waste products ) ( are ( filtered ( from ( the blood ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS kidneys)) (VP (VBP are) (SBAR (WHADVP (WRB where)) (S (NP (NN urine)) (VP (VBZ is) (VP (VBN formed))))) (, ,) (SBAR (IN as) (S (NP (NN waste) (NNS products)) (VP (VBP are) (VP (VBN filtered) (PP (IN from) (NP (DT the) (NN blood)))))))) (. .)))
The kidneys are where urine is formed, as waste products are filtered from the blood.
(ROOT (S (NP (NNP Urine)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (NP (JJ liquid) (NN waste)) (VP (VBN formed) (PP (IN by) (NP (NNS kidneys)))))))) (. .)))