XXY klinfilter which has extra-

Ans. is 'a' i.e., X-ehromosomeo The major numerical disorders of chromosomes are 3 autosomal trisomiesTrisomy 21 -- Down syndromeTrisomy 18 - Edwards syndromeTrisomy 13 - Patau syndromeo Four types of sex chromosomal aneuploidies:Turner syndrome (usually 45,X)Klinefelter syndrome (47,XXY)47,XXX47.XYYo By far the most common type of trisomy in liveborn infants is trisomy 21 (karyotype 4 7,XX, +21 or 47,XY, +21) or Down syndrome.