Turner's syndrome affects females that only inherit one of this structure, while Klinefelter's syndrome affects males who inherit two.
An abnormal number of repeats of the CGG trinucleotide in the FMR1 unit of this structure can result in a form of mental retardation. Dosage compensation serves to equalize expression in these structures, and the inactivation of one of these structures in the healthy human female results in a Barr body. Turner's syndrome affects females that only inherit one of this structure, while Klinefelter's syndrome affects males who inherit two. This chromosome carries mutated alleles that can result in disorders such as hemophilia and red-green color blindness. For 10 points, name this sex chromosome, of which female humans carry two but males carry only one along with a Y chromosome.
An abnormal number of repeats of the CGG trinucleotide in the FMR1 unit of this structure can result in a form of mental retardation.
X chromosomes [prompt on "chromosomes"]