Question

What evidence suggests that while the XIST gene may be required to initiate X chromosome inactivation, it may not be required to maintain it from one generation to another?

a)Some tumor cells in women contain inactivated X chromosomes whose XIST gene has been duplicated.
b)Some tumor cells in women have no X chromosomes.
c)Tumor cells do not maintain X chromosome inactivation from generation to generation.
d)Some women have patches of cells in their retinas that are color blind and others that are not.
e)Some tumor cells in women contain inactivated X chromosomes whose XIST gene has been deleted.

Answer 1

Some tumor cells in women contain inactivated X chromosomes with duplicated or deleted XIST genes, suggesting that the XIST gene is not required to maintain X chromosome inactivation.

Step-by-step explanation:

The evidence that suggests the XIST gene may not be required to maintain X chromosome inactivation from one generation to another is that some tumor cells in women contain inactivated X chromosomes whose XIST gene has been duplicated or deleted. This indicates that the XIST gene is not necessary for maintaining X chromosome inactivation. Additionally, the fact that tumor cells do not maintain X chromosome inactivation from generation to generation also supports the idea that the XIST gene is not essential for maintaining this process.