( ( A ( sex-linked trait ) ) ( ( is ( ( one ( whose allele ) ) ( is ( located ( on ( ( ( ( one ( of ( the ( sex chromosomes ) ) ) ) , ) usually ) ( ( the X ) ( for ( autosomal traits ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (JJ sex-linked) (NN trait)) (VP (VBZ is) (SBAR (WHNP (WHNP (CD one)) (NP (WP$ whose) (NN allele))) (S (VP (VBZ is) (VP (VBN located) (PP (IN on) (NP (NP (NP (CD one)) (PP (IN of) (NP (DT the) (NN sex) (NNS chromosomes)))) (, ,) (ADVP (RB usually)) (NP (NP (DT the) (NNP X)) (PP (IN for) (NP (JJ autosomal) (NNS traits))))))))))) (. .)))
A sex-linked trait is one whose allele is located on one of the sex chromosomes, usually the X for autosomal traits.
(ROOT (S (NP (JJ Sex-linked) (NNS traits)) (VP (VBP are) (VP (VBN located) (PP (IN on) (NP (NP (NNS genes)) (PP (IN on) (NP (NN sex) (NNS chromosomes))))))) (. .)))