( Humans ( ( have ( ( ( about 100,000 ) genes ) ( in ( ( 23 pairs ) ( of chromosomes ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Humans)) (VP (VBP have) (NP (NP (QP (RB about) (CD 100,000)) (NNS genes)) (PP (IN in) (NP (NP (CD 23) (NNS pairs)) (PP (IN of) (NP (NNS chromosomes))))))) (. .)))
Humans have about 100,000 genes in 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))))) (. .)))