In order to get my cherry trees to have cherries, I had to plant two
dissimilar varieties. This is what I don't get. Variety A needs a
var B to pollinate it. Var A produces cherries. I plant the seed.
Presumably this seed has DNA from both A & B. When this seedling
matures it will require a pollinator in order to make cherries. How
would I know if it needed an A or a B type?
In species where varieties are self infertile, how is it that the
varieties can stay in any way distinct?
I'm 43 and I've wondered about this for most of my life, so thanks in
advance for your replies.

--Bryan