Using a Punnet Square is good, but what percentage would you guess at it being totally wrong?

Answering #96: Yes, this is possible.

Going back to genetics the blood groups of your parents would look like this, using a Punnet Square:

A O

B AB BO

O AO OO

What this means is your parents carry the genes for both A and O type blood. There is a 25 percent chance these will give AB blood (like your brothers) and a 25 percent chance they will give O blood (like yours).

My father has O Negative, and my mother has A Negative, so will that be enough to tell me my blood type?

My father is type A and my mother is type B. My four brothers are type AB. why is it that my blood type is O. Is this possible?

I am 0- and my son is 0+, what would the blood type of his father be? Is it 0+

I am O negitve and my mother says she is B postive. what is my father's blood type?

If I have an A- blood type what would have been the possible blood types for my parents?

If everyone is really so concerned about how their family members' blood types match up, just draw a good ol' Punnett Square. Basically, you have to know what two blood type genes are being carried by each parent. The possibilities are A, B, and O, and each parent will have 2 of those in combination: A parent: A/A or A/O (I'd assume A/O, just to make it easier.) B parent: B/B or B/O (I'd assume B/O, just to make it easier.) AB parent: A/B O parent: O/O Once you've decided what blood type genes the parents carry, draw a 2x2 square. Put one parent's two letters along the top of the square, and those of the other parent down the left side. I'll use my own parents (B father, O mother) as an example: __O__O_ B|__|__| O|__|__| Then, just go row-by-row and match up the letters: __O__O_ B|BO|BO| O|OO|OO| The combinations inside the square are the possible combinations for the blood type of any children they may have. O is always recessive, so BO or AO means the child will have B or A blood, respectively. OO naturally means O blood, and AB obviously means AB blood. Thus, for the example of my parents, the possible blood types of their offspring are either B (the BO combination) or O (the OO combination). And sure enough, my blood type is B.

@83: It's a very odd way of phrasing it, but I assume this woman means that she inherited a positive Rh factor from one parent, and a negative from the other. Assuming that is the case, she has both positive and negative *genes*, but her blood is positive.

The most important part (in summary): ~2 Type-A parents...can produce A or O children. ~1 Type-A parent, 1 Type B parent...can produce AB, A, B, or O children. ~1 Type-A parent, 1 Type AB parent...can produce AB, A, or B children. ~1 Type-A parent, 1 Type O parent...can produce A or O children. ~2 Type-B parents...can produce B or O children. ~1 Type-B parent, 1 Type-AB parent...can produce AB, A, or B children. ~1 Type-B parent, 1 Type-O parent...can produce B or O children. ~2 Type-AB parents...can produce AB, A, or B children. ~1 Type-AB parent, 1 Type-O parent...can produce A or B children. ~2 Type-O parents...can only produce O children. @79: I think you're the one who needs to work on their knowledge of genetics. Go read post no. 28. It specifically states that your example is impossible. We don't just magically carry every blood type that has ever been expressed in our family. We've all got two - and only two - blood type alleles, one from each parent. (Rh factor is determined at a separate spot in our genes.) Since there are three possible allele types (A, B, and O), we're all missing at least one of them. Type A people can have: 2 As; 1 A, 1 O Type B people can have: 2 Bs; 1 B, 1 O Type AB people can only have: 1 A, 1 B Type O people can only have: 2 Os We each pass on *one* of our two alleles (selected essentially at random) to our offspring: AB people can pass on A or B. A people with 2 A alleles can only pass on A. A people with 1 A and 1 O can pass on either. B people with 2 B alleles can only pass on B. B people with 1 B and 1 O can pass on either. O people can only pass on O. The combination of that allele with the allele passed on by our partner determines the baby's blood type. The theoretical combinations work like this: 1 A, 1 B gives the child AB. 1 A, 1 O gives the child A. 1 B, 1 O gives the child B. 2 As gives the child A. 2 Bs gives the child B. 2 Os gives the child O. Therefore, a type B mother can pass on B, and theoretically O if she has a B/O combination herself. A type O father can *only* pass on O. So, your example of a B mother and O father only has two possibilities: type B children (B from the mother, O from the father) or type O children (O from the mother, O from the father). That couple cannot ever produce type A children. Take me, for example. My mother is O, my father is B. I all three of my siblings are also type B, either because my father had a B/B combination or because he had B/O and just happened to always pass on his B allele.

read #28 people.

If the mother is O+ and the son A+ ? What is the father? Is O- possible?

do all blood brothers and sisters have the same blood type or can one have a different blood type?

Hi, when I had an ectopic pregnancy I discovered I was A- blood type. my mum asked how this was possible as she says both her and my dad are O.

I know a woman that says that see has positive and negative blood. Is that possible?

my blood type is O and my husband is AB then why that my son is type B? it is possible?

I am O+ and my childs father is AB- and my child (daughter) is A-. Is this possible?

i have type o positive blood and my mom is ab with rh- factor and my father is type a how can i be type o? note: all my nine brothers and sisters are a positive or ab with rh negative factor. now that my parents are gone, my mom since age two, and i am 44 and my father 5 years ago. it may not be significant to others but to me it is.

Learn some basic genetics people. You all are far too concerned about this. Truth be known, the gene that determines your blood type expresses itself as all of the options (A,O,B, etc) in your sperm/eggs. Mother with B, and Father with O can certainly have a child with type A! For example a grandparent on each side could have A!

I have A+ blood, my wife has O (not sure if it is + or -). My son has B+ blood. We were told in the hospital that it happens all the time and could just be a regressive gene. Is this true? Is there a possibility that he may not be my son? :(

my mum was AB- and my dad was o+ and I am o- but have been told this isnt possible.

Can parents with blood types O+ and B+ have a daughter with blood type AB+?

What blood type am I if both my parents are 0 RH Negative?? Just curious, do 2 negatives make a positive?

I am type B+ and my husband is O+ What is the possible blood type of our baby?

Both my husband and myself have a positive blood types, our child is O positive. My husband's grandmother was O positive. Is that why our child is O positive

I am A+ and my boyfriend is AB- what type would our daughter have

can a female with A- and a male with o+ have a daughter with A+ blood?

If the mother is O and the child is A What should the father type be?

If I am A+ and my husband is A- what blood type are my children likely to be?

I am type B+ and my wife is O. My daugther is type O+, is that possible?

My girlfriend is O- and I'm AB+. Would our baby be an O+ ?

I have O- my son has B+ and the alleged father has A+ is this possible? I need to know because no paternity test has been done and I was never married to him and the courts in Louisiana have granted him joint custody without a paternity test and I just found out about the blood types. I need to know so I can have this reversed because this man is refusing my son to come back to live with me even though he wants to.

Me and my husband's blood type is O+, and my son is type A+. My husband's father is type A+, is it possible that my son inherited my father in law's blood type?

I have been typed 4 times in my life. Twice it came up as O+ and twice it came up as O-.

It is not one of those things I really worry about, but it is something I would like an answer too.

Both my husband and i have 0- blood type, i am pregnant, does that mean our baby will be 0- ?

Is it safe for a woman who is B+ and a man who is A- to have children? I remember learning in Anatomy in high school that if a woman has a negative bloodtype and a man has a positive bloodtype, and if the child turns out to be positive, that would be bad for the mother. I am B+ and my fiancee is A-, if we were to get pregnant, would that be a problem to me?

Can a father that is B- have a son that is B-? Not sure what the mother is?

My husband thinks all kids take the fathers blood type. He has 0+ and I have B-. Our child has B+. Is this possible?

My husband and I have six children, including two sets of twins. We are both type A+, and our four oldest children are type A+. The last two, twin girls, are type O+. Possible, or am I in trouble?

If I am ab+ and my son is ab+ then can the father have an O blood type?

My mother is type a and my father was type o my brother was type b and I am type ab rh negative. Which one is my parent and which one is not my parent?

There must be an answer to O blood types having A or B children. They say that O can only pass on O, but there are too many of us with this problem.

I am O+, by husband O+, we have 3 children O+, A+, A-. It is just hard to find out why. Most websites say O can only pass on O. It cannot be true. I know who the father of my children is. I just wish I could find out why this can happen.

is it possible for a baby to have O+ blood and its parents are A+ (mother) and AB+ (Father)

I'm blood type o+ and my husband is A+, but our daughter is B+...is it possible for our daughter to have that type of blood?

so you get four bits of genetic codes

two from each parent

so you can have an O even if one parent is an A or B

it just means one parent has two O bits and the other has one recessive O:

a three in one chance of an O.

can both parents with O+ positive rhesus factor have a baby? and how difficult can it be to conceive?

I am O positive and my son is O positive. My son's father is A positive. Is this possible or should I be worried?

Can one parent with RH- blood and the other parent with O+ blood have a child with AB blood?

My Mother just called me and told me she just found out her father (who has passed away) is O+ and her Mother ( who is still alive but doesn't know who she is) has O-. My Mother is A+. Please help figure this out for her. She is devastated. Thank you

my dad is B positive and my mom is O positive, i am A1 positive. is it possible?

I am very confused I have O+ and my husband also is O+. My two children also are O+ and my third who was born a week ago turns out to be B+...the pediatrician tells me it is possible for O's to carry B's but I read that its not possible..should i have him retested or can it be??

Is it possible for one parent to be AB- and the other to be A+ and have a O+ baby?

My mother who is living is o positive and my father who has passed away was o negative. I am A negative. I have no doubt that I am my father's daughter, I look too much like him, my feet are the same as his and so are my hands which aren't the norm. I am even short like my dad was. I have looked everywhere and it seems that from many science articles, there is no way that I could biologically be his. If there is anyone out there that can tell me different, please write back. Maybe there was a mistake with his blood type and he was indeed A negative. I know once I went to the emergency room and my blood came back ab negative when I had been told I was a negative when pregnant with my first child. Just would like to discuss this and see what others think. If you saw my dad and I together, you would not doubt. Too my parents were in love and planned me. Look forward to the replies.

My husband and I are both blood donors and have been typed as O+, my son is O+ as well. Recently my daughter found out from her OB-GYN that she is A-...how is that possible? (My father was O-, but I do not know the blood types of my mother or my husband's parents.)

If the mother is A- and the father is A- will the child be A- or can he also be type O-?

I was my mother's second child. I was A- and they changed my RH factor to +. My question is..My daughter was born as 0- Since I am A+ and her father is B+ how did we have a 0- child. Could she have inherited my negative gene? My mother was neg and I am not sure about my father because he passed away when I was very young.

I have a question, I hope I can get an answer to. I am O+ and I believe my husband is O+ or O-, 2 of my 3 children are O+ but one is A what does this mean? Please help me understand

My mom was adopted and died young. There is a question of infedelity. I know my dad has O+ and my sister is RH-. I am AB+ What would my mom have to be? My dad thinks she was O+ also. Plz answer

I have O positive blood and my sister has B positive. Is it possible that we have the same parents?

Is it possible for the Mother to have O+, and the Father to have B+, but the child to have AB-?

Is it ok if the mother has O positive blood and the father has A positive and the child has A negative blood type

Is it possible for one sister to have blood type B+ and another sister to have blood type O+ and have the same parents?

I have O+ blood and my husband has O- blood.

What blood types could our child have?

There are numerous factors in calculating blood types and unfortunately we cannot provide that specific service here at wiseGEEK. We are, however, committed to providing general information about the topic which should help answer your questions. But, you can type "blood type calculator" into your search engine and you should get several easy-to-use options to calculate specific blood type possibilities!

Here are some general points though. There are two main categorizations of blood type to consider when you're talking about how it is passed on: (1) the blood type (i.e., A, B, AB, and O), and (2) the Rhesus (Rh) factor (i.e., positive (+) or negative (-).

Blood Type

People with type A blood can pass on either A or O.
People with type B blood can pass on either B or O.
People with type O blood can pass on only O.
People with type AB blood can pass on either A or B.

Once you've determined the parental blood types you can see the possibilities for the children. (You can also work it backwards if you know the child's blood type and one of the parent's to discover the other parent's blood type.) A parent with O type and a parent with A type blood can have O or A children. The only way to get AB blood is if (i) both parents are AB or (ii) one parent is A and the other is B or (iii) if one parent is AB and the other is A or B. When one parent is AB, then the child cannot be O. You cannot get a blood type that the parents do not have (i.e., a parent with type O blood and a parent with type B blood cannot have a child with type A blood).

While these general rules apply most of the time, the body is very complex and there are things like recessive anomalies that can occur. The best way to know anything for sure is to get some answers from a qualified medical professional.

Rh Factor

People with Rh+ can pass on Rh+ or Rh-.
People with Rh- can only pass on Rh-.

Two people with Rh- can only have a child with Rh-. But two Rh+ people or, a Rh+ and a Rh- person, can have Rh+ or Rh- children.

My question was whether an O neg. mom and an A pos. Dad can have a baby with O pos.? How do I get an answer to this question? thanks

My question was whether an O neg. mom and an A pos. Dad can have a baby with B pos.? How do I get an answer to this question? thanks

I am type o+ and my husband is B+ our baby is type A, is that possible?

Can an O+ Father and an O+ Mother have an O- child?

A person only has type O blood if they got one O from each parent. If you get an O from one parent and a B from the other, you'll have type B blood. So an O parent and a B parent with B kids will have received one O and one B, making them have type B.

Negative Rh works like type O, so that the only way to have negative blood type is to receive the negative gene from both parents.

This means that even though your blood type looks like O+, what you actually got from your parents (and have the ability to pass to your kids) is OO+-. That is, a positive blood type can actually pass on a positive or negative blood type. A negative blood type, however, only can pass on negative.

So, someone with a B+ blood type can pass on B or O blood that is positive or negative.

Hi eyes, You're right to ask — it's not possible. If you have type O blood, the only possibilities for your child are O, A, or B, depending on the blood type of the father.

If I have an O blood type and my baby has an AB blood type does that mean the dad is AB also or is that even possible?