If the father donates an “X”, the child will be female with two “X” chromosomes. One “X” from each parent. The average male also has two sex chromosomes, but only one is an “X”; the other is a “Y” chromosome. If the father donates a “Y” the child will be male, because males have an “X” and a “Y”. If everything goes well, the child always gets an “X” from its mother because females only have “X” chromosomes. A child will get either an “X” or a “Y” chromosome from its father because males have an “X” and a “Y” chromosome. So, what’s the big deal here? Immune System function is carried on the “X” chromosome. Great for females. If Immune system function on one “X” is weak, hopefully, it will be stronger on the other “X” chromosome. If immune system function is strong on both “X’s” hurrah for her. She is fortunate, unless her lifestyle choices suppress Immune function and then, too bad, all around. More tomorrow.