Barr bodies: Difference between revisions
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A barr body<ref>''Barr body'' http://en.wikipedia.org/wiki/Barr_body September 3, 2014.</ref> is an inactive [[X chromosome|X chromosome]] in female cells or the inactive Z in a male. [[Lyonization|Lyonization]] is the process where the chromosome is inactivated in species. | A barr body<ref>''Barr body'' http://en.wikipedia.org/wiki/Barr_body September 3, 2014.</ref> is an inactive [[X chromosome|X chromosome]] in female cells or the inactive Z in a male. [[Lyonization|Lyonization]] is the process where the chromosome is inactivated in species. In addition to this, it is thought to be down to complete chance as to which X chromosome is inactivated and it is still unknown to this day as to how the cell decide which X chromosome is to be made into a Barr body. [Sloane.e, The Biology Of Women] | ||
In men and women with more than one X chromosome, the number of Barr bodies visible at interphase is always one less than the total number of X chromosomes. | In men and women with more than one X chromosome, the number of Barr bodies visible at interphase is always one less than the total number of X chromosomes. | ||
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=== References === | === References === | ||
Sloane.E, The Biology of Women, 4th Edition, Cengage Learning, 2002, pages 133 | |||
Revision as of 13:49, 22 October 2015
A barr body[1] is an inactive X chromosome in female cells or the inactive Z in a male. Lyonization is the process where the chromosome is inactivated in species. In addition to this, it is thought to be down to complete chance as to which X chromosome is inactivated and it is still unknown to this day as to how the cell decide which X chromosome is to be made into a Barr body. [Sloane.e, The Biology Of Women]
In men and women with more than one X chromosome, the number of Barr bodies visible at interphase is always one less than the total number of X chromosomes.
For example, a man with Klinefelters syndrome, with 47 chromosomes, XXY karyotype have two Barr bodies, whereas an female with Turners syndrome, with 45 chromosomes, XO karyotype does not have any Barr bodies.
References
Sloane.E, The Biology of Women, 4th Edition, Cengage Learning, 2002, pages 133
- ↑ Barr body http://en.wikipedia.org/wiki/Barr_body September 3, 2014.