Transcript Blood type

Blood Types
Co-dominance
• When two or more alleles for a
gene contribute to the phenotype
Blood type alleles
•
•
•
•
IA = type A marker (antigen)
IB = type B marker (antigen)
IO or just I = No markers (antigen)
Antigen – means marker on the surface
of a cell
**antigens are how your body can
identify which cells belong to you and
which are foreign**
Antigens vs. Antibodies
• Antigens are how your body recognizes
which cells are yours and which cells are
foreign.
• Antibodies are what your body produces to
fight off any cell that is not “marked” as
yours.
THINK – PAIR - SHARE
• If there are 3 co-dominant alleles, how
many different blood types (phenotypes) are
possible?
• 4 possible blood types
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–
–
–
A
B
AB
O
Type A blood
genotypes = IAIA or IAIO
Has only A antigens on the surface
Has Anti-B antibodies
A
Type B blood
B
O
B
B
genotypes = I I or I I
Has only B antigens on the surface
Has Anti-A antibodies
B
B
B
B
B
Type AB blood
genotype = IAIB
Has A and B antigens on the surface
B
No antibodies!
B
B
B
Type O blood
genotype = IO IO
Has NO antigens on the surface
Makes Anti-A and Anti-B
antibodies
Rh Blood Group
• Rh positive indicates presence of antigen D
• Rh negative indicates absence of Antigen D
• Rh antigens, like A and B antigens are inherited and
present from birth
• Anti-D antibodies are not produced until after an
individual is sensitized to antigen D
Fig. 14.21
What blood can I receive?
Blood type:
Can receive from: Can give to:
Type A
A or O
A or AB
Type B
B or O
B or AB
Type AB
A, B, AB or O
*UNIVERSAL
RECIPIENT
O only
AB only
Type O
A, B and AB
*UNIVERSAL
DONOR
What happens if
the wrong blood
type is given?