With Respect to X-Chromosome Inactivation in Females, Which, If Any

question 3

Multiple Choice

With respect to X-chromosome inactivation in females, which, if any, of the following statements is incorrect?

• A) X-inactivation first occurs in the preimplantation female mammalian embryo.
• B) One of the two X chromosomes in each diploid cell of a normal woman is randomly selected to undergo X-inactivation and becomes highly condensed.
• C) The process involves epigenetic silencing of each gene on one of the two X chromosomes, either the maternal X chromosome or the paternal X chromosome.
• D) Once the decision is made to inactivate a paternal X or the maternal X in a cell, all descendant cells will continue with that pattern of X-inactivation.

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Definitions:

Equity Multiplier

A financial ratio indicating the portion of a company’s assets that are financed by stockholder's equity.

Debt-to-equity Ratio

An indicator of the distribution between shareholders' equity and borrowed funds in financing a company's assets.

Times Interest Earned Ratio

A financial metric that measures a company's ability to pay its interest expenses with its before-interest earnings.

Gross Margin Percentage

A financial metric indicating the percentage of revenue that exceeds the cost of goods sold, representing the proportion of each sales dollar that is gross profit.