I found the exercise on the internet and this is how the genotypes should look like (these genotypes are ABO blood system genotypes):
[tex] I^{A} [/tex]i and [tex] I^{B} [/tex]i
Attached is a Punnett square that represents the crossing between both parents and the possible genotypes of their children.
You can do a Punnett square by inserting on both entries of the table the alleles that correspond to each parent, being each table entry a parent genotype (as shown in the table/Punnett square below). Then, join the alleles from each parent as they appear related to the central squares. The formed genotypes are then the possible genotypes of their children - [tex] I^{A} [/tex][tex] I^{B} [/tex], [tex] I^{A} [/tex]i, [tex] I^{B} [/tex]i, and ii