Download blood notesMULTIPLE ALLELES

MULTIPLE ALLELES
 The ABO blood group is an example of a multiple
allele.
 The three alleles for this gene are: IA, IB, i.
(IA = A; IB = B; i = O)
 IA and IB are codominant (dominant over i)
 IA and IB produce antigens – specific markers found
on RBC.
 Antibodies – free floating marker that binds to
specific antigens.
Blood group
Antigen on Can receive
Cannot
RBC
from Donor receive from
(Clumps)
A
A
A or O
B or AB
B
B
B or O
A or AB
AB
A&B
A,B,AB,O
NONE
O
NONE
O
A,B,AB
Cross a heterozygous blood type B male with a
heterozygous blood type A female.
P1♂ IB i x IA i ♀
P1♂ BO x AO ♀
IA
i
A
O
IB
IA IB
IBi
B
AB
BO
i
I Ai
ii
O
AO
OO
GR: 1 IA IB: 1 IBi: 1 IAi : 1 ii GR : 1 AB : 1 BO : 1 AO : 1 OO
PR: 1 type AB: 1 type B: 1 type A: 1 type O