Please help. The +/- is called the rhesus factor, with + being dominant, and - being recessive. So if both parents are -, the kids are always -, … The below charts show how contributions from each parent determine the blood type of the child. A and B are both dominant over O, which means a child that receives an A from the father and an O from the mother will have a type A blood. Since one of my siblings is A+ and there has been a doubt about her parentage and in her inheritance. Since AA, AO and OA are blood type A, and OO is blood type O, thus their child has 6.25% chance to be blood type O and 93.75% chance to be blood type A. Using a Punnett square is a great way to figure out a child’s possible blood types based on the parents’ blood types. Depending on which combination each parent has determines the different combinations that the child can have. There are four major blood groups determined by the presence or absence of two antigens – A and B – on the surface of red blood cells. The actual blood type of a child is determined by the dominant type between the two parents. Since the red cell antigens are inherited as dominant traits, a child cannot have a blood group antigen that is not present in one or both parents. If you know the mother and child’s type, then you can use the following chart to narrow the list of possible types for the father. ABO Blood Groups. Q: If the parents' blood groups are O+ and B+, can one of their offspring be of any other blood group other than these two? Our interactive blood group calculator determines a baby's probable blood types for the ABO system based on the parents' blood type and vice versa. There is a one in four chance of your child getting a different combination of genes from the genotypes of the biological parents. For instance, if the biological parents’ blood types are O and AB, the baby may be born with either blood type A or B. In addition to the A and B antigens, there is a protein called the Rh factor, which can be either present (+) or absent (–), creating the 8 most common blood types (A+, A-, B+, B-, O+, O-, AB+, AB-). Ok so now we have everything we need to predict what blood type a child will likely have given two parents. You get it based on equal genetic contributions from both parents. Each of these blood types is different from both parents. There are four common values: A, B, AB, and O. Find the child's value in yellow and the mother's value in blue. Blood group - Blood group - Paternity testing: Although blood group studies cannot be used to prove paternity, they can provide unequivocal evidence that a male is not the father of a particular child. Briefly, here’s how blood typing works. For example, if the mother is AO (received A from one parent and O from the other) and the father is BO there is a possibility that their child will have one of the following blood types: A (25%), B (25%), O (50%), or AB (25%). All we need to know are the parents’ blood genotypes. In the United States, O+ is the most common blood type, found in about 37% of the population, followed by A+ in around 36% of people, according to the Stanford School of Medicine Blood … How to Figure Out a Child’s Possible Blood Type. Determine Parents' Blood Type Child's Blood Type: A B AB O