Correct Answer - Option 1 : 1
Concept-
- The chromosomal disorders are caused due to absence or excess or abnormal arrangement of one or more chromosomes
- The total number of chromosomes in a normal human cell is 46 (23 pairs).
- Out of these 22 pairs are autosomes and one pair of chromosomes is a sex chromosome.
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Down’s syndrome, Turner’s syndrome, Klinefelter’s syndrome are common examples of chromosomal disorders.
Explanation-
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Klinefelter’s syndrome is caused due to the presence of an additional copy of the X-chromosome resulting in a karyotype of 47, XXY.
- An inactive X chromosome in the cell which has more than one X chromosome is called a bar body.
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Female(XX) have one Barr body.
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Male(XY) have no Barr body.
Therefore Klinefelter's syndrome has 47, XXY means 1 Barr body.
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Down's syndrome is caused due to the presence of an additional copy of chromosome number 21 (trisomy 21).
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Turner's syndrome is caused due to the absence of one of the X chromosomes i.e., 45 with XO.