Every individual has two chromosomes; each carrying A,
B, or O are chromosome from each parent. The inheritance of the A, B and O gene
from one parent and the A, B or O from the other to make a pair of genes called
genotype (Abayomi, 2007).
B, or O are chromosome from each parent. The inheritance of the A, B and O gene
from one parent and the A, B or O from the other to make a pair of genes called
genotype (Abayomi, 2007).
The diagram below explains inheritance of blood group.
The possible ABO genotypes are AA, AO, BB, BO, AB and
OO
OO
a. Group A –phenotype A
Genotype AA (homozygous) and AO (heterozygous)
b. Group B –phenotype B
Genotype BB (homozygous) and BO (heterozygous)
c. Group O –phenotype O
Genotype OO (homozygous)
d. Group AB and phenotype AB
Genotype AB (heterozygous)
Laws of Inheritance
The laws of inheritance have been proven in accordance
with Bernstein theory.
with Bernstein theory.
1. The offspring cannot
possess the antigen A or B, alone or in combination, except that it can be
inherited from one or both parents.
possess the antigen A or B, alone or in combination, except that it can be
inherited from one or both parents.
2. The parent of group AB
cannot produce an offspring of group O, nor can a parent of group O give birth
to a child of group AB. This is because the AB is heterozygous, so that the A
gene must come from one parent and B gene from the other.
cannot produce an offspring of group O, nor can a parent of group O give birth
to a child of group AB. This is because the AB is heterozygous, so that the A
gene must come from one parent and B gene from the other.
(Baker and Silverton, 2007).
