Blood Group Types?

Question

Some background -

A man has A+ Blood.

A woman has O Blood.

A son born with A+ Blood. Naturally, this Blood group mixing confirms the father of the boy is the biological father.

(This is before DNA testing came into existence)

Now for the question -

if a boy is born of the same mother, does the boy, having B-type Blood, the biological son of the father, who has A+ Blood?

I don't believe so.

I would appreciate people giving knowledgeable answers to this question. Giving search references would help your chances of getting the Best Answer for 10 points.

People giving "game-pointing" type answers are not appreciated.

Answer 1

Man has A+, so his genotype might be AA++, AA+-, AO++, AO+-
Woman has type O blood. Her genotype is OO. We have no information about whether she is positive or negative.

So your question is whether a child who has B- blood could come from these two parents. That answer is "no". There aren't any B alleles available from the parents listed above.

Children from these two parents may be type A or Type O only.

Note: Most texts show these alleles as IA IB and i. It's just easier to explain here using A, B, and O.

Answer 2

This is easy with a punnet square.
The woman has the double recessive o so all she can give her kids is o.
The man can be AA or AO. (actually, it is written I^I^ where the ^ is A or O...)

The children of this man will all be A if he is AA and half will be A and half O if he is AA.

The website below shows the punnet squares method for doing a similar problem:
http://www.biology.arizona.edu/human_bio/problem_sets/blood_types/01t.html

[Edit. If that wasn't obvious, if he is type A, his kids can only be A or O, assuming that he's not chimeric and all the genetics of the family are normal (ruling out weird mutations)...so no B son. B is fairly rare...I'd see if the milkman as B or AB]

Answer 3

I'm a B-(negative).. I only know 1 other person who has the same blood group