With Respect to X-Chromosome Inactivation, Which, If Any, of the Following

question 21

Multiple Choice

With respect to X-chromosome inactivation, which, if any, of the following statements are not correct ?

• A) X-chromosome inactivation in mammals begins in the pre-implantation embryo
• B) In humans all diploid cells that carry two normal X-chromosomes are subject to a random pattern of X-inactivation.
• C) Once a decision has been made to inactivate an X chromosome (either the paternal or maternal X), all descendant cells show the same pattern of X-inactivation.
• D) The inactivated X chromosome becomes a highly condensed Barr body in which genes are silenced across the length of the chromosome.

---

Definitions:

New Technologies

Innovations and advancements in technology that create new products, processes, or methods, often leading to enhanced efficiency or productivity.

Socially-Optimal Quantity

The level of production or consumption of a good that leads to the maximum welfare for society, considering both benefits and costs.

Market-Equilibrium

A state where the quantity of goods supplied equals the quantity of goods demanded, resulting in a stable price.

Negative Externality

A cost that is suffered by a third party due to an economic transaction that they were not involved in.