( ( ( The ( primary organ ) ) ( for excretion ) ) ( ( is ( ( the kidney ) ( which ( ( releases waste ) ( in ( ( the form ) ( of urine ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ primary) (NN organ)) (PP (IN for) (NP (NN excretion)))) (VP (VBZ is) (NP (NP (DT the) (NN kidney)) (SBAR (WHNP (WDT which)) (S (VP (VBZ releases) (NP (NN waste)) (PP (IN in) (NP (NP (DT the) (NN form)) (PP (IN of) (NP (NN urine)))))))))) (. .)))
The primary organ for excretion is the kidney which releases waste in the form of urine.
(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)))))))) (. .)))