Question

Number of Barr Bodies in XXXX female is

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is C 3

Barr body is an inactive X chromosome which becomes tightly coiled into heterochromatin in early embryogenesis. It is related to dosage compensation which is accomplished by the inactivation of one of the X chromosomes in females. This is done so that both males and females have only one functional X chromosome per cell because human males have only one X chromosome, whereas females have two and hence twice the genes present on the X-chromosome. The number of Barr bodies is one less than the total number of X chromosomes. Hence, a female with 4 X-chromosomes (XXXX) will have 3 Barr bodies.

So, the correct answer is option C.