BIOLOGY 12
Multiple Alleles and Blood Types
Blood Type
 the alleles of blood type control the production of
antigens on the surface of the red blood cells
 antigen – a substance that prompts the
generation of antibodies and can cause an
immune response
Blood Type
 four types:
 A
 B
 AB
 O
 the Rh factor refers to whether the blood has the
immunogenic D antigen
 this is independent of the ABO system
Blood Type
 the antibodies recognize foreign antigens and
work to destroy them
 A and B are co-dominant and O is recessive to
both
 Canadian Blood Services
 Blood Types Tutorial
Blood Type
 genotypes:



Allele IA produces antigen A
Allele IB produces antigen B
Allele i produces no antigen
 the I stands for isohemagglutinin (compound
that allows for clumping)
Blood Type
 so which blood type is the universal donor?

Type O
 which is the universal receiver?

type AB
Practice
 show a cross between a mother who is
heterozygous type B and a father who is
heterozygous type A
 what is the probability that the child will be
type AB?