Please explain Punnett Square Result when One Parent is AB & One is A?

Question

I am trying to understand HOW these things work - as I guess it was not as simple as I thought?

Answer 1

Are you looking at blood types?

If one Parent is AB and another is A?,   the A? has to be AA or AO.

So the gametes would be A or B for the AB parent

And A or A for the second parent if the ? is A

But if ? is O, the the second would be A and O.

The cross would be  1:1 AA and AB if the ? is A.

The cross would be AA, AO,AB, BO if the? is O

If ? is A:    

          A       A

A       AA     AA

B       AB     AB

or if ? is O:

        A         O

A      AA      AO

B      AB      BO