Blood Types Problem Set

Problem 6: Do we all have the same biological father?

Help to answer the question

We were surfing the net for information on how to confirm blood types inherited from our parents. Your home page offered a lot of good, basic information, but since we are non-bio-science types, our understanding is dated back to high school. Could you offer a reference that would be helpful to figure out blood typing. We understand that a ABO matrix is part of it, and we expect it to be technically over our heads - but we're willing to try. Our basic question is: What is the blood type consistency of two parents who are O+ who have 8 children? 2 of 8 are reported to be O+ and O-. Does that seem to be likely?? --John

Tutorial

Blood type

The parents are either O+/O+ or O+/O-. We really can't distinguish.

There are three possible crosses:
1. O+/O+ x O+/O- ====> All children are O+
2. O+/O+ x O+/O+ ====> All children are O+
3. O+/O- x O+/O- ====> Children could be either O+ or O-

It is very unlikely that the writer would be able to determine whether his parents are O+/O+ or O+/O-. The best answer to this question would be that, given no additional information, the children could be either O+ or O-.

This is a very interesting situation, since any of the eight children that were not type O would have a different biological father.

The Biology Project
University of Arizona
Thursday, October 23, 1997 Contact the Development Team