How are Barr bodies quantified in males and females?

The correct answer involves the quantification of Barr bodies, which are inactivated X chromosomes found in female mammals. In females who have two X chromosomes, one of these is randomly inactivated during embryonic development. As a result, females typically have one Barr body per cell; hence, the number of Barr bodies is calculated as one less than the total number of X chromosomes.

In males, who have one X and one Y chromosome, there are no Barr bodies because there is only one X chromosome to consider, and it remains active. Therefore, when you assess the total number of X chromosomes present, males will have zero Barr bodies.

This understanding highlights that Barr bodies are specifically linked to the presence of two or more X chromosomes; therefore, the quantification aligns with the formula of one less than the total number of X chromosomes. Thus, the calculation reflects the physiological mechanism of X inactivation, confirming that the answer correctly describes how Barr bodies are quantified in both males and females.