Download Blood Typing - TWHS 9th Grade Campus

Blood
Typing
Types
• There are four types of blood due
to the surface molecules present.
• These surface molecules are called
antigens.
• The four types are:
–A
–B
– AB
–O
Importance
• Why do we need to know our blood
type?
– Transfusion--Incompatible blood
types could clump together and result
in death.
– Cases of disputed parentage
Donating & Receiving
Blood
Type:
A
Can give
to:
A, AB
Can receive
from:
A, O
B
B, AB
B, O
AB
AB
A, B, AB, O
O
A, B, AB, O
O
Universals
• Universal Donor: Type O
– Can donate blood to any blood type
• Universal Recipient: Type AB
– Can receive blood from any blood
type
What does the + and –
mean?
• The Rh factor genetic information is also
inherited from our parents, but it is
inherited independently of the ABO
blood type alleles.
• There are 2 different alleles for the Rh
factor known as Rh+ and Rh-.
• Someone who is "Rh positive" has at
least one Rh+ allele, but could have two.
Their genotype could be either Rh+/Rh+
or Rh+/Rh-. Someone who Rh- has a
genotype of Rh-/Rh-.
Inheriting Blood Type
• Inherited from your mother &
father.
• Caused by multiple alleles.
– (In other words, more than two alleles
exist for a trait.)
• Due to the presence or absence of
certain molecules on the surface of
red blood cells.
Blood Genetics
• The gene for blood type is “I”.
• There are three different alleles:
– IA
– IB
–i
• IA and IB are co-dominant and i is
recessive.
– This means that neither A or B will
block out the other.
Genotypes & Phenotypes
Phenotype
Genotype(s)
A
IAIA or IAi
B
IBIB or IBi
AB
IAIB
O
ii
Disputed Parentage
• A lady has a baby but is unsure of who
the father is. The child has AB blood
and the mother has type A.
• We know a man with Type O blood
could not be the father.
• The father would have to have type B
blood.
• Remember: Blood tests alone cannot
prove a definite father, indicates only
that he could be.
Practice
• Mom is heterozygous for type B
blood.
• Dad is heterozygous for type A
blood.
• What are the possible blood types
for their children?