Q. In Barr body (sex-chromatin) of a normal female
A) One of the X-chromosome of paternal side becomes inactive to form Barr body
B) Y-chromosomes form Barr body
C) Heterochromatin condense near centre of nucleus to form Barr body
D) One of the X-chromosome of maternal side becomes inactive and form Barr body near nuclear membrane
Explanation
In body cells of a normal female, one of the X-chromosome become inactive and form Barr body near the nuclear membrane. XY genotype has no Barr body. XX genotype has single Barr body. XXX genotype have two Barr bodies. XXXX genotype have three Barr bodies.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.