The fact that calico cats are only female supports the theory of
A) testosterone inactivation of Y-chromosome genes.
B) mutations in all genes on one X chromosome.
C) X-chromosome inactivation and Barr bodies in females.
D) two X chromosomes being required for coat color in cats.

Question

Quizplus · Accepted Answer

Calico cats are almost exclusively female because their coat color is determined by genes on the X chromosome. Females have two X chromosomes, and the phenomenon of X-chromosome inactivation leads to the varied patches of color. This process also results in the formation of Barr bodies, which are inactivated X chromosomes visible in the nucleus of cells.

The Fact That Calico Cats Are Only Female Supports the Theory