Question

Male (XY) or Female (XX), Which one is dominant and how to determine it?

Answer 1

There is no YY in general.
XY chromosome is not the dominant or recessive manner to think, it passed with "cross-link" However, you can say that Y-character will always show up, so you can say Y is dominant.... And Y chromosome is very small, but X is big and X has the basic critical character to survive, but Y has mostly male character, so without X, it would not be alive as long as I know.
Also, there is another reason why no YY.
Let me show you why there is no YY with an example. Let put number on each Xs.
Eg)
YX1 (father) and X2 X3(mother)
The chance of combination are only these in general;
YX2(boy)
YX3(boy)
X1X2(girl)
X1X3(girl)
So boy and girl has the same 50% chance. and no produced YY.
In few abnormal case like YX, but Y is not working, so a person does not like a man and lived as woman until they find out no able to have a baby and find out defect of Y gene and lived as a woman without knowing it. But this abnormal case also cannot have a baby so no way to be able to have YY.