If my parents (biological) and I all have blood type B, how likely am I a pure blood? (expressed as a percentage)
Follow up question: If my dad is blood type AB instead of blood type B, and everything else is the same as above, will this change increase or decrease my chance of being a pure blood? (can you answer this without extensive calculation?)
Explanation and Clarification:
- The blood type in this question refers to the ABO blood type controlled by the A, B, O genes. Blood type A is either AA or AO, B is BB or BO, O is OO and AB is AB.
- A pure blood in this question refers to a person having two identical blood type alleles, that is all people of blood type O (OO), some people of blood type A and B (AA, BB) but no one of blood type AB.
- Unless specified otherwise, a blood type A or blood type B person has a 50% chance of being a pure blood (AA, BB)