Transcript Genetics of Blood Types

Genetics
of Blood
Types
Genotypes and Phenotypes
• Type A, Type B , Type AB and Type O blood are
phenotypes. It is not always possible to tell
the genotype of a person from their blood
type.
• For example, a person with type A blood could
have the genotype AA or AO
• A person with type B blood could have the
genotype BB or BO
• If a person has type AB blood they must have
inherited an A allele from one parent and a B
allele from the other.
• A person with type O blood must have the
genotype of OO since the O allele is recessive
to both the A allele and the B allele.
Rh factor
• Rh factor is inherited independently from the
ABO blood factors.
• There are two alleles: Rh + and Rh• A person that is Rh+ might be Rh+/Rh+ or they
might be Rh+/Rh• A person that is Rh- must be Rh-/Rh-
. Suppose a father of blood type B and
a mother of blood type O have a child
of type O. What are the chances that
their next child will be blood type O?
Type B? Type A? Type AB?
• Make a punnett square to show the possible
outcomes.