Both parents are B positive. How many chances are there that their son is A positive?

Question

is it medically possible? the other child of the same set of parents have o positive. There are only two children. Please tell the possibility the son is A positive?

Answer 1

Hmmm, I think it's possible for them to have an O child, but I'm not sure about the B.

Are you sure they're both B or could they be AB?

Answer 2

Yes it is genetic but blood type is co-dominant. The plus or minus is related to Rh factor and is more complicated but also inherited. For example, if the husband is AB he could've given either a dominant A or a dominant B to the son. Since you have a B blood type that means you are either BB or Bb, but since the son is A, you must be Bb and she received the recessive b allele from you and the dominant A allele from her father, so her blood type is Ab, but because the A is dominant and the b is recessive, we just say A.

Answer 3

the baby should have the same blood type as one of the parents. thats what i have always been taught but hey it could be wrong??

Answer 4

No chance. Unless one parent is AB blood type, they will only have B or O children. Occasionally they do make mistakes so mum, dad and A positive son should all be retested to make sure.

Answer 5

Not Possible...

There are 4 possible ABO phenotypes: A, B, AB, and O

There are 2 possible Rh factors: + and -

That makes 8 possible blood types (phenotypes): A+, B+, AB+, O+, A-, B-, AB-, O-

There are even more genotypes:

for Type A phenotype: You can have AA or AO

for Type B phenotype: You can have BB or BO

for Type AB phenotype: You can have only AB

for Type O phenotype: You can only have OO

Each parent will give one gene toward ABO blood type

If you mother is type O, then her genotype is OO, so her gamete will have type O

If your father is type A phenotype, then you don't know his genotype, it can be AA or AO, and his gamete can be A or O

so the resulting offspring can be

AO or OO, but not AA

O is a recessive, A and B are dominant

so if one parent is type A (genotype AA) and one is type B (genotype BB), the offspring will be type AB

but if parents are AO and BB offspring can be AB or B (genotype AB or BO)

for the most diversity, one parent AO one BO can have offspring of AO, BO, OO, or AB genotypes.

Type O parents will only produce type O offspring.

The Rh factor is as, + is dominant, - is recessive.

So ++ and +- genotypes express as + phenotype, whereas -- is the only way for - phenotype.

So two - parents only produce - offspring, but a + (could be ++ or +-) and - (only - -)parent can produce + (+-)and - (- -) offspring.

So O neg (OO--) and O pos (OO++ or OO +-) will produce OO ++ or OO +- which means only Type O positive.