( ( A human ) ( normally ( ( has ( ( 23 pairs ) ( of chromosomes ) ) ) . ) ) )
(ROOT (S (NP (DT A) (NN human)) (ADVP (RB normally)) (VP (VBZ has) (NP (NP (CD 23) (NNS pairs)) (PP (IN of) (NP (NNS chromosomes))))) (. .)))
A human normally has 23 pairs of chromosomes.
(ROOT (S (NP (NNS Humans)) (VP (VBP have) (NP (NP (CD 23) (JJ pairs) (NNS pairs)) (PP (IN of) (NP (NNS chromosomes))))) (. .)))