A recessive mutant allele of an autosome gene in a species of mouse results in a shorted tail in males when homozygous. However, when homozygous in females, this genotype has no effect, and the mice have normal tails. What is this genetic phenomenon called?

sexual chromosome linked characteristics

Explanation:

The sexual crhomosomes are XX (for females) and XY (for males).

The Y chromosome have less genes than the x, because of this, some characteristics are expressed at males and not at females.

Males has only one copy of the gen, carried by the only X chromosome (in this case, the leght of the tail). Nevertheless the females have two copies of the gen, (short and long tail).

So, the fenotype resulting is a dominant characterisitic related to x chomosome (long tail).