The child would have either the blood group A, B or AB. The rhesus factor may be positive or negative in the child.
See, the blood groups are determined by what alleles each DNA strand carries in a person. The alleles are A, O, and B. These may be in combination with each other to give different blood types. It is important to know that A and B are dominant. Thus whenever they are present, they are expressed. If there are both A and B present, they are co-dominant and form the blood group AB. Blood group O only occurs when both alleles are OO. Each parent passes only one strand on to the offspring in their gametes so that each person includes 50% DNA from each parent.
So, for blood group AB, the possible allele combination (genotype) is A B. For blood group B, the possible combinations are OB or BB.
Thus, if we put these in a punnet square, we see what offspring we may get:
Parents genotype AB BB
Gametes A B B B
Zygote/baby AB AB BB BB
Blood group of baby AB AB B B
So, there is a 50-50 probability of the child being AB or B.
If, the parent with the blood group B has the genetic make up OB, then:
Parents genotype AB OB
Gametes A B O B
Zygote/baby OA AB OB BB
Blood group of baby A AB B B
So, there is a 50% probability of the child having the blood group B and 25% probability of the child having either blood group A or AB.
See, the blood groups are determined by what alleles each DNA strand carries in a person. The alleles are A, O, and B. These may be in combination with each other to give different blood types. It is important to know that A and B are dominant. Thus whenever they are present, they are expressed. If there are both A and B present, they are co-dominant and form the blood group AB. Blood group O only occurs when both alleles are OO. Each parent passes only one strand on to the offspring in their gametes so that each person includes 50% DNA from each parent.
So, for blood group AB, the possible allele combination (genotype) is A B. For blood group B, the possible combinations are OB or BB.
Thus, if we put these in a punnet square, we see what offspring we may get:
Parents genotype AB BB
Gametes A B B B
Zygote/baby AB AB BB BB
Blood group of baby AB AB B B
So, there is a 50-50 probability of the child being AB or B.
If, the parent with the blood group B has the genetic make up OB, then:
Parents genotype AB OB
Gametes A B O B
Zygote/baby OA AB OB BB
Blood group of baby A AB B B
So, there is a 50% probability of the child having the blood group B and 25% probability of the child having either blood group A or AB.
