Human Blood Typing (Multiple Alleles) Mrs. MacWilliams Biology

I. WHEN IS BLOOD TYPING DONE? blood transfusions blood donation organ donation for transplantation women planning to/become pregnant determination of blood relatives identify crime suspects

II. ANTIGENS AND ANTIBODIES A. ANTIGENS Markers on surface of blood cells Most important antigens: A, B, O, and Rh

B. ANTIBODIES Formed against certain ANTIGENS in blood Destroy foreign antigens and blood cells

What happens when you get the wrong blood type? 1.) The person’s body will recognize the ANTIGENS on the wrong blood as being foreign. 2.) The white blood cells will make ANTIBODIES to fight the foreign ANTIGENS. 3.) The foreign blood cells will burst and AGGLUTINATE and the person will die.

III. Blood Type Compatibilities A BLOOD: A antigens on the RBC Creates antibodies against type B Genotypes: IAIA or IAi B BLOOD: B antigens on the RBC Creates antibodies against type A Genotypes: IBIB or IBi

Blood Type Compatibilities O BLOOD NO antigens for A or B Antibodies against BOTH A and B Genotype: ii “Universal Donor” Can donate to any blood type O is RECESSIVE to A and B

Blood Type Compatibilities AB BLOOD BOTH A and B antigens on RBC NO antibodies for either Type A or Type B Genotypes: IAIB “Universal Receiver” Can receive blood from any blood type A and B are CO-DOMINANT

IV. Rh FACTOR Rhesus Monkey A. Named for the Rhesus Monkey in whose blood it was first found. Rhesus Monkey

Rh FACTOR C. Rh blood typing Presence of Rh antigen (+) System consists of at least 8 different antigens of which the most prominent is called antigen D. 1. About 85% of Americans of Western European descent are Rh positive, which means that they have Antigen D on the surface of their red blood cells. 2. That means that the other 15% have no antigen D on their cells and are termed Rh negative. When they are exposed to Rh+ blood they form antibodies against the antigens on the Rh+ cells. C. Rh blood typing Presence of Rh antigen (+) Absence of Rh antigen (-)

D. Genotypes (complete dominance) Homozygous positive = + + Heterozygous Positive = + - Homozygous negative = - -

V. Rh Incompatibility A. Situation: mom = Rh- baby = Rh + 1. Baby’s blood crosses into mom’s blood via placenta 2. Mom forms antibodies against baby’s blood 3. Mom’s blood (with antibodies) crosses back into baby 4. Baby’s immune system begins to destroy all of its red blood cells 5. Baby becomes severely anemic and often dies B. The disease: Erythoblastosis fetalis C. The Rx: The drug Rhogam (taken before conception)

PERCENTAGE OF BLOOD TYPES BLOOD TYPE WORLD % O 45 % A 41 % B 10 % AB 4 % Rh + 85 % Rh - 15 %

TRANSFUSION CHART O- O+ A- A+ B- B+ AB- AB+ Anti-A, Anti-B, Anti Rh Blood Type Antibodies in blood Transfusion type O- Anti-A, Anti-B, Anti Rh O+ Anti-A, Anti-B O-, O+ A- Anti-B, Anti-Rh A-, O- A+ Anti-B A+, A-, O+, O- B- Anti-A, Anti-Rh B-, O- B+ Anti-A B+, B-, O+, O- AB- Anti-Rh AB-, A-, B-, O- AB+ No Antibodies AB+, AB-, A+, A-, B+, B-, O+, O-

Crosses. There are 21 possible crosses between the 6 possible genotypes. Cross Possible Blood Types AA x AA AA AA x AO AA, AO AA x BB AB AA x BO AB, AO AA x AB AA, AB AA x OO AO AO x AO AA, AO, OO AO x BB AB, BO AO x BO AB, AO, BO, OO AO x AB AA, AB, AO, BO Cross Possible Blood Types AO x OO AO, OO BB x BB BB BB x BO BB, BO BB x AB AB, BB BB x OO BO BO x BO BB, BO, OO BO x AB AB, AO, BB, BO BO x OO BO, OO AB x AB AA, AB, BB AB x OO AO, BO OO x OO OO

BLOOD TYPING WEB SITES http://sln.fi.edu/biosci/blood/rh.html www.nobel.se/medicine/educational/ http://sln.fi.edu/biosci/blood/rh.html www.bloodbook.com http://www.biology.arizona.edu/ http://www.ucs.louisiana.edu/~bkd3019/blood.html