Question

Which of the following statements about X inactivation in mammalian females is FALSE?

a) X inactivation occurs randomly in cells during early development.

b) X inactivation ensures that each cell in females has only one active X chromosome.

c) The inactivated X chromosome is reactivated during gamete formation.

d) X inactivation is a mechanism to equalize gene dosage between males and females.

Answer 1

The false statement about X inactivation is that the inactivated X chromosome is reactivated during gamete formation. In fact, the inactivated X chromosome remains dormant in egg cells.

Step-by-step explanation:

The statement about X inactivation in mammalian females that is FALSE is: c) The inactivated X chromosome is reactivated during gamete formation. X inactivation is indeed a random process occurring early in development where one of the two X chromosomes in each cell is inactivated to form a dormant structure known as a Barr body. This inactivation ensures gene dosage compensation between males and females, meaning that each cell in females, like males, only has one active X chromosome. However, contrary to the statement, the inactivated X chromosome is not typically reactivated during the formation of gametes (eggs), as eggs always carry an active X chromosome.