I am correct on the blood types: Both parents had O Positive blood, my 3 siblings have O Positive, and I have A Negative. It is my understanding two O Positives can NOT produce an A Negative, which means, of course, the obvious. Unfortunately, I can't ask my mother; she died over 10 years ago.
Lydia's sister(A name would be helpful )-I'm going to agree with Cogito. I've studied this topic for two years in detail in biology and when the mother is AB, the father can be OA, OB,OO. If the father is O, we talk about genotype, which is the inherited code in the genetic stucture and need not be projected as the phenotype. So the children can be AA, BB, OA, OB, AB. The only thing they can't be is pure OO. The parents contribute 50/50. The allele dominance/recessiveness factor doesn't play a role in this situation because we're talking about what CAN and what CANNOT be.
This is Lydia's sister once more, my name is Melody ;-) ( just hope this doesn't annoy anybody, I would register, if I didn't think it a little useless, since it's just for this one topic...) I'm still convinced that I am right, I've been looking up a few websites, see the links below, they may be better at explaining the blood type inheritance than I am.. ;-) I'm sorry if I seemed a little blunt in my last post, Cogito. I still don't agree with you or Neha though. Is it possible that you are thinking about a type A parent and a type B parent? Since their genotypes can be resp. AO (Ia i) and BO (Ib i), for them (and only in this case) it is possible to have kids with the four different bloodtypes. these are a few links to websites, quite useful I believe, one is about the specific problem we've been dicussing here .... http://www.canadiancrc.com/Paternity_determination_blood_type.aspx http://www.bloodbook.com/inherited.html http://en.allexperts.com/q/Genetics-1795/Blood-type-inheritance.htm http://en.wikipedia.org/wiki/Blood_type
