Which of the following are properties of a Barr body?
a) It is a darkly stained region near the nuclear envelope of
interphase cells.
b) It is formed as part of a mechanism for dose
compensation.
c) It is the same X chromosome in every cell.
d) It is an inactivated X chromosome.
e) The number of Barr bodies per cell is always equal to half
the number of X chromosomes present.