Question

an indivisual have b blood group what will be genotype?​

Answer 1

The genotype will be BB or BO.

Likewise, for blood group A, you can be either AA or AO. Both blood groups AB and O have only a single genotype: AB and OO, respectively.

This distinction makes it that your blood group does not need to match the blood groups of your parents. For example, if your parents have blood groups AB and O, then you can be either A (AO) or B (BO). In this case it is actualy impossible (or rather, extremely unlikely) to have the same blood group as your parents.