( ( In humans ) ( ( the ( sex chromosomes ) ) ( ( comprise ( ( one pair ) ( of ( ( the total ) ( of ( ( 23 pairs ) ( of chromosomes ) ) ) ) ) ) ) . ) ) )
(ROOT (S (PP (IN In) (NP (NNS humans))) (NP (DT the) (NN sex) (NNS chromosomes)) (VP (VBP comprise) (NP (NP (CD one) (NN pair)) (PP (IN of) (NP (NP (DT the) (NN total)) (PP (IN of) (NP (NP (CD 23) (NNS pairs)) (PP (IN of) (NP (NNS chromosomes))))))))) (. .)))
In humans the sex chromosomes comprise one pair of the total of 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))))) (. .)))