Final answer:
Morris has the genotype ii and can be James' son since both A and B parents can produce an O type child. Felix, with AB blood type, cannot be the father. Blood donation compatibility between Donna and James depends on their specific ABO genotypes and the absence of transfusion reactions due to antigens.
Step-by-step explanation:
The question concerns the ABO blood group system and how it determines the possible genotypes of offspring. Since Donna is blood type A and James is blood type B, their son Morris, who has blood type O, must have the genotype ii because blood type O is always homozygous recessive. Given Felix's blood type AB, it is impossible for him to be Morris's father because someone with AB cannot have a child with O blood type, as AB indicates the presence of at least one A and one B allele. However, James could be the father because the genotypes AO and BO can produce an O type child when each parent contributes a recessive i allele.
Donna's ability to donate blood to James depends on the specifics of the ABO system. Since Donna has blood type A, she can donate to James (blood type B) only if he is not type B (BB), because the B antigens would cause a transfusion reaction. Conversely, James can donate blood to Donna as long as she is not type A (AA) because A antigens from her blood would react with the B antigens in his donated blood.
In the ABO blood group system, the D antigen is not a part of this system but is related to the Rh factor, which is separate from the ABO system. Hemolytic disease of the newborn may be more likely to occur in a second pregnancy due to the mother's immune system being sensitized to the baby's Rh-positive blood during the first pregnancy, leading to an immune response that could affect subsequent Rh-positive fetuses.