is it possible for an guy who has A- blood type to be the father of an O+ baby when the mother is O-?

Answer 1

Absolutely NOT.

Let's just ignore the A/O factor, because we don't even need to go there. The evidence is in the Rh factor. Rh negative is a recessive trait, meaning you have to have two copies of the negative gene. If you have one negative and one positive, then you will always have Rh positive blood because positive is dominant.

If father is Rh negative, then his genotype is -/-. So is mother. Neither one of them can carry an Rh positive gene. So baby has to have gotten the Rh positive gene from somewhere, but not from this father.

Answer 2

No, the O blood type is recessive, so for a baby to have the O blood type both parents will have to have it. So therefore if the guy has A- blood type and the baby is O+ his is not that childs father.

Answer 3

Yes, because O is recessive and the male with the A- blood type may be AO. I'm not great at the genotyping thing, but if you google "A- father O- mother O+ baby" you'll see several detailed answers (some of which come from Yahoo! Answers).

Answer 4

Yes, it is possible. It is possible for As and Os to have A or O children (but not B or AB).

Also, the Rh positive gene is dominant (stronger) and even when paired with an Rh negative gene, the positive gene takes over.

Of course, this doesn't exclude others from being potential fathers; the only sure way to know is to have a blood type test done on the baby. But, to answer your question, it is possible and probable given the facts you outline.

(See reference links)

Answer 5

Nope the child will share the blood type of one of the parents.

My mom= O positive
My dad= A positive

Me= A positive

My mother thought because she was O positive that I was. WOW when I get pregnant I found that I was A pos. She had told me my dad was O positive as well... Found out from the hosp where he died that he was A pos...Scary stuff

She would have had an RH factor problem as well

Answer 6

The A- could be AA or AO, so it is possible to have a type-O child.

However, the Positive is dominant; if a person is negative, they have 2 negative genes - one from each parent. Someone who is Positive, may have a negative from one parent, and a positive from the other; or a positive each from both.

Obviously, if both parents are negative, they both have 2 negtive "alleles", and have no positive to give to the child. It will get 2 negatives and be negative.

Therefore, it is impossible for a pair of negative parents to have a positive child.

Answer 7

No, its not. But only because in order to have negative blood, you have to not carry a positive. An A or B blood type can carry a recessive O and it will only show as A(Ao) or B(Bo), and a positive can carry a negative(+-) instead of being just all positive(++) BUT a negative is all negative(--). Hope this makes sense.

Answer 8

The short answer is yes.
ABO blood grouping O is usually dominant however when it comes to the Rh factor which is + or - it becomes far more complicated. + is the dominant gene however we all carry two Rh factors. Meaning that because the guy is + he can be ++ or +- which would both be considered +. Now it is possible that you passed your - and he passed his - (if he is +-) then naturally your child would be -- which is a - Rh factor. However the only conclusive test to determine paternity is a DNA test.

Answer 9

No it is not possible they would have either an O- or an A- blood type child because of the RH factor.

Answer 10

It is possible to have and O baby because the father can be AO and the mother is OO but i'm not sure about the posstive/negative thing...negative is rescesive, so it might not be possible