A B AB O
The blood type O means that the parent has two O alleles. This is because O is recessive and only expressed when both alleles match. The blood type A means that the parent either has two A alleles or one A and one O. This is because A is dominant and will be expressed any time it is present. The blood type B means that the parent either has two B alleles or one B and one O. This is because B is dominant and will be expressed any time it is present. The blood type AB requires one A allele and one B allele. Both are dominant and expressed equally.
A+ A- B+ B- AB+ AB- O+ O-
For example, if the father has the blood type “A,” you would need to list allele combinations “A,A” and “A,O. ” That would mean you have four alleles going down the leftmost column (three A’s and one O).
For instance, if the mother had the blood type “AB,” there is only one allele combination that could produce it. That means you would write two alleles in the first row (one A and one B). A Punnett square can be used to determine other traits as well. For example, you can use a Punnett square to predict your baby’s eye color.
Homozygous means that the father carries only one type of allele (O,O). Heterozygous means that the father carries two different alleles (A,O).
For example, you would fill in the first square with the “A” allele from the father and the “A” allele from the mother.
In the case of a parent with type “A” and a parent with type “AB,” there will be eight boxes.
For example, you might have eight squares total with three AA’s, three AB’s, one AO, and one BO.
AA = ⅜ = 37. 5% chance AB = ⅜ = 37. 5% chance AO = ⅛ = 12. 5% chance BO = ⅛ = 12. 5% chance In this case, there is a 50% chance that the blood type will be A, since both AO and AA will express as blood type A.
