A friend and I are having an argument and she says that "O-" blood types can only exist in the first child between a mother and father. Is she right? I know the blood type is rare as he or she is the universal donor, but it can't be as common as being the first child, right?
2006-10-26 18:52:11 · 16 answers · asked by soul_shattering 1 in Science & Mathematics ➔ Biology
she is wrong and you are right. it is not so simple as being the first child. if both parents are type O, all children can be type O
2006-10-26 18:57:26 · answer #1 · answered by Anonymous · 1⤊ 0⤋
There's two different parts to this question. First the letters: the vast majority of people fall within the A/B/O blood types. A and B are both dominent, so they work out like this:
AO = A type
AA = A type
BO = B type
BB = B type
AB = AB type
OO = O type
Each parent donates half of the pair to the child... So if one parent is AO and one is BO, they could have an OO baby. Birth order has nothing to do with it.
The +/- has to do with the Rh factor. Everone is either positive or negative. It's an issue because a negative person will have a reaction to a positive person's blood... like in a transfusion. So the doctors have to know the Rh factor. A positive person will not have a reaction to a negative blood type.
In pregnancy, there is frequently some blood leakage between the baby and mother, especially during labor. So if the Mom is negative and the baby is positive, she could develop a reaction. This won't bother her or the baby because the exposure was very brief. However, if the Mom has a another positive baby, her blood will attack the baby's blood, which is bad. So they give Rh negative pregnant women special Rhogram shots to avoid the reaction.
Also, the positive is dominant to the negative, so they work out like this:
+ + = Rh positive
+ - = Rh positive
- - = Rh negative
Hope that helps!
2006-10-27 02:13:08 · answer #2 · answered by lunartaffy 2 · 1⤊ 0⤋
The blood type of a child is not affected by whether a child is the first or not.
55% of people in Britain have the O gene (without A or B blood agents), but only 13% don't have the rhetus gene (the negative means rhetus negative). Hence 8% of our population are O negative.
You get two different genes from your parents, and they will fight it out to give you your blood type. There is some chance involved but some genes have an advantage- O has a good advantage, but rhetus negative has a big disadvantage.
2006-10-27 02:13:01 · answer #3 · answered by Peter F 5 · 0⤊ 0⤋
Birth order has nothing to do with the LETTER part of a blood type. It's always a grab bag, randomly selected from what the mother and father have to offer. (see http://anthro.palomar.edu/blood/ABO_system.htm for more about that) just like the rest of the child's genetics.
As far as the connection between mother and fetus when it comes to the +/- thing, that get's a little more complicated. A child is only at risk if it is Rh-, and the mother is Rh+. This presents the possibility of the mother's Rh+ white blood cells crossing over the placenta and attacking the baby's red blood cells. This risk increases with each pregnancy, but if both the mother and the child are Rh-, there's not problem.
2006-10-27 02:03:07 · answer #4 · answered by ZenNihilism 2 · 1⤊ 1⤋
No she is wrong. Blood type is determined by genes. For instance there is two type of A-blood type Ai and AA. Each letter represents what the father (A) gave and what the mother gave (A or i) same for blood type B- Bi or BB, AB only has one type AB and O-blood type also has one type ii...so if my dad was Ai but my mom was Bi I could be blood type O if by chance I had ii but then I could also be any of the other types too.
If your parents are O though you have a higher chance of having and O-blood type too but so do the rest of your siblings.
2006-10-27 03:36:00 · answer #5 · answered by katiefenton22 1 · 0⤊ 0⤋
Your friend is confused. The Rh factor is the one that comes into play with a first child only. IF the mother is Rh negative, and gives birth to an Rh positive child, (absent modern medicine) she can at delivery become exposed to the Rh positive factor and can subsequently make antibodies to the Rh factor. In subsequent pregnancies with Rh positive babies, that can be fatal.
Please disregard Zenni's comments above, she is confused also, has it quite the opposite. I worked in a blood bank for seven years.
2006-10-27 10:42:42 · answer #6 · answered by finaldx 7 · 0⤊ 0⤋
Nope she is wrong...if a child is O- then the parents have the capability to produce more children of same blood type.
If parents were both type O then can only have type O kids and then it becomes what rh factor genes the kid got from each parent
2006-10-27 07:44:08 · answer #7 · answered by Anonymous · 0⤊ 0⤋
O is the worlds most common blood type. It is not impossible that the second child can't have O-
2006-10-27 03:27:05 · answer #8 · answered by pokemon_jirachi555 1 · 1⤊ 0⤋
I was under the impression that the blood type was determined by the father. In mother's with o negative blood types, don't they have to receive an injection when pregnant with a child fathered by a positive blood type?
So to answer your question, I don't know. Sorry
2006-10-27 02:02:33 · answer #9 · answered by Kble 4 · 0⤊ 3⤋
hi my name is kathy and im the second child have one older brother and my blood type is o positive
2006-10-27 02:03:24 · answer #10 · answered by schofieldqma 1 · 1⤊ 0⤋