( ( Each ( human cell ) ) ( ( contains ( ( 23 pairs ) ( of chromosomes ) ) ) . ) )
(ROOT (S (NP (DT Each) (JJ human) (NN cell)) (VP (VBZ contains) (NP (NP (CD 23) (NNS pairs)) (PP (IN of) (NP (NNS chromosomes))))) (. .)))
Each human cell contains 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))))) (. .)))