explain the cause of chromosomal disorder in humans. describe effect of such disorder with the help of an example each involving autosomes and sex chromosomes

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The chromosomal disorders are caused due to absence or excess or abnormal arrangement of one or more chromosomes. Failure of segregation of chromatids during cell division cycle results in the gain or loss of a chromosome(s), called aneuploidy. For example- klinefelter's syndrome, Down's syndrome etc.

Chromosomal disorder involving sex chromosomes:
Klinefelter’s Syndrome: In this syndrome one extra X chromosome is present in male sex chromosomes making it XXY (normally XY). It results in feminized male which means male with female characters. The frequency of occurrence of this syndrome is 1 in 500.

Chromosomal disorder involving autosomes:
Down’s Syndrome caused due to the presence of an additional copy of chromosome 21 (Trisomy of 21)
Here in this genetic disorder the affected individual has short stature, small, round head, furrowed tongue, partially opened mouth, palm crease, congenital heart disease and mental retardation.

Hope this information will clear your doubts about the topic.    Regards