( ( A vector ) ( ( is ( ( an organism ) ( which ( ( spreads disease ) ( from ( ( one host ) ( to another ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN vector)) (VP (VBZ is) (NP (NP (DT an) (NN organism)) (SBAR (WHNP (WDT which)) (S (VP (VBZ spreads) (NP (NN disease)) (PP (IN from) (NP (NP (CD one) (NN host)) (PP (TO to) (NP (DT another)))))))))) (. .)))
A vector is an organism which spreads disease from one host to another.
(ROOT (S (NP (NP (DT An) (NN organism)) (SBAR (WHNP (WDT that)) (S (VP (VBZ carries) (NP (NNS pathogens)) (PP (IN from) (NP (NP (CD one) (NN individual)) (PP (TO to) (NP (DT another))))))))) (VP (VBZ is) (VP (VBN called) (NP (DT a) (NN vector)))) (. .)))