( ( White ( blood cells ) ) ( ( are ( called leukocytes ) ) . ) )
(ROOT (S (NP (NNP White) (NN blood) (NNS cells)) (VP (VBP are) (VP (VBN called) (NP (NNS leukocytes)))) (. .)))
White blood cells are called leukocytes .
(ROOT (S (NP (JJ Leukocytes) (NN blood) (NNS cells)) (VP (VBP are) (ADJP (JJ white))) (. .)))