Anonymous
Anonymous asked in Science & MathematicsBiology · 4 weeks ago

# If my mom's blood type is O+ and my dad's blood type is A-, would it be O+ since positives dominate?

Update:

I found out. My blood type is A+

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• MARK
Lv 7
4 weeks ago

Your question is based on what I do not know. It certainly has no sound basis in science. You say that positives dominate but that statement is both vague and incorrect. It is vague because you do not indicate what is positive. It is incorrect because it is simply meaningless.

You have probably heard of blood groups. Well, there are a lot of them. When your blood is typed, tested to determine your blood groups, two groups are normally typed. They are the ABO blood group; the other one is the Rhesus blood group. The information you give in your question involves both of these. The ABO blood groups are A, B, AB and O. The Rhesus groups are basically positive (+) or negative (-).

Your mother's ABO blood group is O and your father's is A. Your mother's Rhesus blood group is + and your father's is -. I am only going to deal with the ABO blood group.

We all have a gene* that determines our ABO blood group. It has three possible alleles, which are A, B or O. We have two copies of every gene so we have a mix of alleles for this blood group. We may have the same allele at both copies. This could mean we are AA, BB or OO. Alternatively, we can have a different allele on each copy of the gene. This gives the possibilities of AB, AO and BO.

Next, we have to consider dominance. The alleles A and B are co-dominant and if present are expressed. The allele O is recessive to both A and B. Because O is recessive the only combination of alleles that can give blood group O is OO. If your mother is blood group O she has the alleles OO. Your father has two possible allele combinations. He may be AA or AO. Because A is dominant to O if he is AO he will be blood group A.

When a zygote is produced at conception from an ovum and sperm it receives one allele from each parent. Because your mother is OO she had to give you an O and you will have an O allele. If your father is AA he will have given you an A allele. However, if he is AO he could have given you an A allele or an O one. This means your alleles could be AO (if your father gave you an A) or OO (if your father gave you an O). That means your ABO blood group will be A (if you are AO) or O (if you are OO).

Was that confusing enough? Can see you why I haven't bothered with the Rhesus Group: It is more complicated.

*Two for those who may be picky but I’m trying to keep this as straightforward as possible.

• MARK
Lv 7
4 weeks agoReport

And, what an incredibly puerile comment from a very stupid person.

• Zirp
Lv 7
4 weeks ago

Just because something is dominant (not "dominate") doesn't mean it gets preference. Your mom could carry the rhesus-negative allele, while your dad could carry the 0-allele

• 4 weeks ago

You could end up as A+, A-, O+, or O-.

• 4 weeks ago

It's complete Russian roulette, you can't determine anything.

• MARK
Lv 7
4 weeks agoReport

Russian roulette? What an incredibly stupid answer. No, blood types are based on science not a potentially fatal game for the criminally stupid.