Table 1. Crosses to produce genetically identical sons from fathers with different X-chromosomes.

Sires	Dams	Sons
Xskew/Y ; A/A	Xeven/Xeven ; A/A	Xeven/Y ; A/A
Xeven/Y ; A/A	Xeven/Xeven ; A/A	Xeven/Y ; A/A

X_skew and X_even are X-chromosomes that produce a skewed and an even sex-ratio, respectively. Y stands for the Y-chromosome and each “A” stands for a haploid set of autosomes.