Blood Type!
Blood types!
• Inheritance of blood groups is determined by the
gene “I” which has three different alleles.
• The alleles are responsible for producing antigens
on the surface of the red blood cells, which
determines the blood group.
• Alleles A and B are co-dominant so that when
they are both present, both A and B antigens are
produced. Both A and B are dominant to O.
• Alleles A and B are
co-dominant so that
when they are both
present, both A and B
antigens are
produced.
• Both A and B are
dominant to O.
Type A
Type B
Type AB
Type O
IA an IB are codominant and i is
recessive.
Rh antigens are straight dominant
vs. recessive.
Blood types of
North America
Blood types of
North America
with RH.
Blood Types (A, B, O, AB)
Allele IA – formation of blood factor A (antigen A)
Allele IB – formation of blood factor B (antigen B)
Allele I – no factors result
Genotype
IAIA or IAi
IBIB or IBi
ii
IAIB
Blood Type
A
B
O
AB
Example:
A mother with blood type A has a child with Blood type
O. The father is blood type B. Indicate the genotypes
of the parents.
Father can be IBIB or IBi and mother can be IAIA or IAi.
To have a child that is type O (ii) both mother and father
must contribute the i allele, therefore the father must be
IBi and the mother is IAi