Final answer:
The potential blood types of children from parents both with AB blood type can be A, B, or AB, with a phenotype ratio of 1A:2AB:1B. The children can never have blood type O. An AB blood type woman can indeed donate blood to her AB blood type husband.
Step-by-step explanation:
When two individuals with AB blood type conceive a child, the possible blood types of their offspring can be A, B, or AB. This is due to the A and B alleles showing codominant inheritance, where both alleles are fully expressed. Thus, when we use a Punnett square to predict the most likely blood type among their offspring, we observe that there cannot be a blood type O because neither parent has the O allele (recessive 'i' allele) to pass on.
The genotype of blood type AB is IAIB, representing one allele from each parent coding for different proteins. In a Punnett square with both parents having AB genotype, all possible combinations of alleles result in a ratio of 1:2:1 for A:AB:B phenotypes, with the following potential genotypic combinations: IAIA (A), IAIB (AB), or IBIB (B). There are no combinations that would result in the ii genotype, which would be necessary for an O blood type.
Regarding the question of whether a woman can donate blood to her husband, if both partners have AB blood type, then yes, the woman can donate blood to her husband because AB is a universal recipient, meaning that individuals with AB blood can receive A, B, AB, or O type blood without adverse reactions.