Blood type question regarding siblings....?

Question

Ok, my husband is a type o+, the man we believe to be his father is also a 0+, as his that mans other biological son. My husband (the o+) has an older brother who is a B+ blood type, they have the same mother(deceased-blood type unknown). My question is, does it take 2 os to make an o? an ao mom can make an o son with one man who is also an o and a b son with another man right? glory i am confused! can only an o and an o make another o? thanks!

Answer 1

It doesn't always take a type O and a type O to make another type O.  An O+ parent can end up with real, biological sons that are O+ and B+, even if the other parent is the same both times.

There are calculators on the internet that can help you figure out what possible combinations work out based on what blood types you know.  Here's an example:  http://www.biology.arizona.edu/Human_Bio...

Here's how it works, genetically:

Every person has two copies of the ABO gene (and two copies of the Rhesus, or +/-, gene).  A and B are codominant over O, so AO and AA make type A, and BO and BB make type B.  AB makes AB, and OO makes O.

Each parent gives one of their copies to the child.  This means that an OO father (type O blood) and a BO mother (type B blood) could make type B or type O children.  The father will always give an O gene, but the mother has a 50/50 chance of given a B gene or an O gene.  

You can even make a type O child when neither parent is type O!  A type A parent with AO genes and a type B parent with BO genes could end up with both parents giving an O gene, and making an O child.

The Rhesus factor works the same way.  Everyone have two copies, and the + is dominant over the -.  This means that + + and + -, genetically, are both type +.  - - is the only type -.  Each parent gives one copy, and it's passed down separately from the ABO gene.

By the way, based on the information you've given, your husband's mother's blood type is B+ or B-.  She has to have a B to give to the other son, since the father can only give an O.  She has to have an O to give to your husband, so she much be BO, which is blood type B.  We don't know the +/- part, because the father could have given the +, and then it doesn't matter if the mother gives + or -, the child still ends up +.

Answer 2

O Child can have A&A, or A&O, or B&B, or B&O, or O&O parents.  See bloodbook.com for more details.

Answer 3

Ok, in blood types O is recessive, meaning it takes both parents to make an O baby.  

A and B are co-dominant, so they are expressed like this:

A+B=AB

A+O=A

A+A=A

B+O=B

B+B=B

O+O=O

I hope that helps.  

Yes a mom who is AO(blood type A) can have children who are both O and AB depending on the father's blood type.

Answer 4

Never mind the blood type, just be glad you have some blood. Get a DNA test done.