Download Allele Red Blood Cell A codominant A

Blood Types
The Genetics of Blood Type
• How many of you know what your
blood type is?
• Blood type is determined by 3 alleles.
• It is an example of a multiple alleles
trait.
• Multiple alleles is a trait that
requires 3 or more alleles.
The Alleles for RBC’s
Allele
A codominant
B codominant
O recessive
Red Blood Cell
A-antigen on RBC (unique
shaped protein.)
B-antigen on RBC
No antigen on RBC
Rh Factor
• Rh factor -- first discovered in the
Rhesus monkey.
Allele
RBC
+ (positive) Has Rh factor protein
on RBC
- (negative) Has no Rh factor
protein RBC
The Genetics of Blood Type
Donor/Recipient?
Universal
Donors/Recipients
• Universal donor is O negative; they
can give blood to anyone because
their RBC’s don’t have any proteins.
• Universal recipient is AB positive;
they already have all of the proteins,
so adding more of any kind will not
make a difference.
WRONG BLOOD TYPE???
• If given the
“wrong” blood type
for medical
purpose, the
immune system
would recognize
the blood cells as
foreign and
destroy them!
• Most common type of blood in the US
is O – 45%
• A is 40%
• B is 11%
• AB is least common with 4%
Phenotypes and
Genotypes
PHENOTYPES
A
B
O
AB
GENOTYPES
AA, AO
BB, BO
OO
AB
The Genetics of Blood Type
How can we predict Blood Type inheritance?
Using a Punnett square!
Let’s look at possible blood types of the children
of a couple whose blood types are B and A.
The Genetics of Blood Type
First we need to determine their genotypes.
From one parent we can get B or O
From the other we can only get A or O
The Genetics of Blood Type
B
A
O
O
The Genetics of Blood
Type
B
O
A
AB
AO
O
BO
OO
The Genetics of Blood
Type
B
O
A
AB
AO
O
BO
OO
• Genotype:
1 AO: 1 BO: 1 OO: 1 AB
• Phenotype:
1 A: 1 B: 1 O: 1 AB
The Genetics of Blood Type
Your homework:
Blood Types Worksheet