if dad had ab blood and baby has b could mom have a?

mom can have AO and dad can have AB

so on d punnett square u get the following 4 d baby:

AA,AB,AO,BO

i.e the baby can well have BO (i.e B blood group)...

hopu u unders2d...

Remember that the gametes (eggs/sperms) only have one of the alleles...

So if dad was AB (gametes would be either A or B).

If mom was A (gametes could be A and A or A and O)

Possible combinations from these parents would be:

Either:

AB x AA = AA; AA; AB; AB

OR

AB x AO = AA; AO; AB; BO

There's baby B!!

There are three alleles or versions of the blood type gene: A, B, and O. Since everybody has two copies of these genes Mom and Dad, there are six possible combinations; AA, BB, OO, AB, AO, and BO. Hope this helps

There are 2 co-dominant genes in humans, they r 'Ia' and 'Ib'. Ia for Blood group A and Ib for Blood group B. There is also a recessive gene, That is 'Io' if and only 2 recessive genes are present then O Blood group appears. If Io is present With Ia or Ib it plays no role except it will be carried to the next generation.

So Father with AB, child having B and mom can have A. Because mom also contains the recessive gene for her blood group i.e., Ia Io. Ia is Dominant over Io.

So the child has got Ib (b-group gene) from father and Io (recessive gene) from mother.