( ( ( What plant ) organ ) ( ( is ( modified ( to ( make ( a ( cactus spine ) ) ) ) ) ) ? ) )
(ROOT (SBARQ (WHNP (WDT What) (NN plant) (NN organ)) (SQ (VBZ is) (VP (VBN modified) (S (VP (TO to) (VP (VB make) (NP (DT a) (NN cactus) (NN spine))))))) (. ?)))
What plant organ is modified to make a cactus spine?
(ROOT (S (NP (NP (DT The) (NNS spines)) (PP (IN of) (NP (DT a) (NN cactus)))) (VP (VBP help) (SBAR (S (NP (PRP it)) (VP (VBP survive) (SBAR (IN because) (S (NP (NNS spines)) (VP (VB protect) (NP (DT the) (NN cactus)) (PP (IN from) (NP (NNS animals)))))))))) (. .)))