CopyCat, the first cloned cat, was derived from an ovarian cell from a female calico cat. But CopyCat was not an exact copy, as she herself was not calico. This result implies that, if the donor female were also heterozygous for an X-linked harmful mutation causing muscle degeneration, the probability of a clone being affected is:
A)0)
B)1/4.
C)1/2.
D)3/4.
E)1)

Question

Quizplus · Accepted Answer

The calico pattern is due to X-chromosome inactivation, which is random. If the donor is heterozygous for an X-linked mutation, the clone has a 50% chance of expressing the mutation depending on which X chromosome is inactivated.

CopyCat, the First Cloned Cat, Was Derived from an Ovarian