( ( Lyme Disease ) ( ( ( ( ( ( ( ( A ( serious illness ) ) ( caused ( by ( the bacterium ) ) ) ) , ) ( Borrelia burgdorferi ) ) , ) ( which ( is ( ( carried ( to humans ) ) ( by ( the ( Deer Tick ) ) ) ) ) ) ) ( -LRB- ( ( Ixodes scapularis ) -RRB- ) ) ) . ) )
(ROOT (S (NP (NNP Lyme) (NNP Disease)) (VP (NP (NP (DT A) (JJ serious) (NN illness)) (VP (VBN caused) (PP (IN by) (NP (DT the) (NN bacterium)))) (, ,) (NP (NNP Borrelia) (NNP burgdorferi)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (VP (VBN carried) (PP (TO to) (NP (NNS humans))) (PP (IN by) (NP (DT the) (NNP Deer) (NNP Tick)))))))) (PRN (-LRB- -LRB-) (NP (NNP Ixodes) (NNS scapularis)) (-RRB- -RRB-))) (. .)))
Lyme Disease A serious illness caused by the bacterium, Borrelia burgdorferi , which is carried to humans by the Deer Tick ( Ixodes scapularis ).
(ROOT (S (NP (JJ Lyme) (NN disease)) (VP (VBZ is) (VP (VBN caused) (PP (IN by) (NP (NNS bacteria))))) (. .)))
Lyme disease is caused by bacteria.