M ULTIPLE A LLELES
A, B, O B LOOD T YPE S YSTEM
Multiple alleles – more than two alleles control a trait
A, B, O System
Alleles are either A, B, or O
Blood types can be A,
B, AB, or O
Example – Human
Blood type is determined by the type of antigen present on the surface of the red blood cell
A NTIGENS AND A NTIBODIES
Antigens – stimulates an immune response when a foreign substance enters the body
Antigens produce antibodies
Antibodies are like
“soldiers,” they destroy foreign substances
B LOOD T YPES
D ONORS AND R ECIPIENTS
Which blood type(s) can A, B, AB, and O receive?
Which blood type(s) can A, B, AB, and O donate to?
Can get blood from…
A, B, AB, O
Can donate to…
A, B, AB, O
M OST /L EAST C OMMON B LOOD TYPE
R H S YSTEM
Rh is an antigen that is sometimes present on the surface of red blood cells
85% of the United States population is Rh positive
This means that they carry the Rh antigen
People who do not have the Rh antigen are called Rh negative (Rh-)
Called the Rh factor
Named after the rhesus monkey in which it was first discovered
Rh+ is dominant over Rh-
People who are Rh- CANNOT receive blood from a person who is Rh+!
If an Rh- person receives a transfusion that is Rh+
the Rh- person will make antibodies against the Rh+ blood
The antibodies will react with the antigens of the Rh+ blood and the two blood types will clump
This clumping is called AGGLUTINATION
R H AND P REGNANCY
If mom is Rh- and dad is
Rh+ = baby will be Rh+
During delivery baby’s blood may get into mom’s bloodstream and she will make antibodies against the Rh+ blood
If she gets pregnant again her antibodies against Rh+ blood can cross her placenta and attack baby
#2 Rh+ blood
P RACTICE COPY IN YOUR NOTES
If one parent has type O blood and the other parent has type AB, what are the possible blood types the offspring could have?
A O A O
B O B O
If both parents are rH+ , is it possible to have a child that is rH- ???
If both parents are type AB, what are the possible blood types of the offspring?
If one parent is type A and the other parent is type AB, what is the chance of having a child with AB?
If one parent is type A and the other parent is type B is it possible for them to have an AB child?
If one parent is A and the other parent is B, is it possible for them to have a child with type O?
If one parent is type A and rH+ and the other parent is B and rH+ is it possible to have a child that is type AB and rh- ? Hint, do your Punnett squares separately!
If one parent is type AB and rH+ and the other parent is AB and rH+, what is the chance of having a child that is type B and rH-?
Hint, both parents are heterozygous for rH factor.