( people ( ( have ( ( 23 pairs ) ( of chromosomes ) ) ) . ) )
(ROOT (S (NP (NNS people)) (VP (VBP have) (NP (NP (CD 23) (NNS pairs)) (PP (IN of) (NP (NNS chromosomes))))) (. .)))
people have 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))))) (. .)))