Multiple Alleles: Blood Typing
Human blood (types A, B, AB, and O) is an example of a trait that (mainly) works according to Mendelian genetics. For instance, there are dominant traits (A and B) and a recessive trait (O) that are the result of specific alleles (note: the A and B alleles are co‐dominant so that, when paired, they produce type AB blood).
Additionally, there is another component to blood typing—the Rh factor—that comes into play, producing positive and negative blood (e.g. A
, etc.). The following tutorials will assist you in learning about how blood types arise and how to determine them using antibodies. Once you have mastered the genetics behind blood types, you can test your skills on cyber‐patients who have recently been in a car crash and need blood!
Go to University of Arizona's Biology Project tutorial on blood types: http://www.biology.arizona.edu/human_bio/problem_sets/blood_types/Intro.html
A. Read the "Introduction" page.
B. Click of the words "Human ABO markers" on the left side of the screen. Read about the ABO markers.
C. Next, click on "Blood types and genotypes?" on the left side of the screen. Read about how blood type genotypes result in different blood type phenotypes. Fill out the table below.
Phenotype Possible Genotype(s)
D. Click on the words "Rh factor" on the left side of the screen. Read about the Rh factor and how it influences blood types. Fill in the table below.
Phenotype Possible Genotype(s)
E. Click on the new “Blood type and Rh Factor calculator” on the left side of the screen and determine both the possible blood type of the child and the possible blood type of the parents. Run the calculator for 4 trials to complete the table below.
Trial 1 Trial 2 Trial 3 Trial 4 (your choice)
Parent 1 blood type A O A
Parent 1 Rh factor + + +
Parent 2 blood type O AB B
Parent 2 Rh factor - + +
Possible blood type(s) for the child
Possible Rh factor(s) for the child
Now, let's test your blood typing skills! Go to the following web site located in the Nobel e‐Museum (from the Nobel foundation ‐ as in "Nobel prize" ‐ in Sweden): http://nobelprize.org/educational_games/medicine/landsteiner/
A. Click on "Play the Blood Typing Game”, proceed, and choose quick game. Read the information and click on main menu on the upper right corner of the screen.
B. Click on the “What is a blood type” tutorial and read the webpage. Answer the questions below.
What is an antigen?
Type A blood contains ________________ antigens on the red blood cell surface.
Type B blood contains ________________ antigens on the red blood cell surface.
Type AB blood contains _______________ antigens on the red blood cell surface.
Type O blood contains ________________ antigens on the red blood cell surface.
Blood that is Rh+ contains _____________ antigens on the red blood cell surface.
Blood that is Rh- contains _____________ antigens on the red blood cell surface.
C. Click on the back button in the red box at the top of the webpage. Click on the “How do you determine a patient’s
blood type?” tutorial and read further down the web page.
It explains how patients receiving a blood transfusion will experience an immunological reaction to the wrong blood type—in other words, when the wrong blood type is given to a patient, their immune system attacks the blood. Unless you have an auto‐immune disorder, your body knows not to attack its own cells, and therefore does not make antibodies against itself. For instance, the immune system of a person with "A" blood would not make "A‐blood antibodies," because if it did, the antibodies would attack the body’s own "A" blood cells. However, a person with "A" blood does make "B‐blood antibodies," because the body “knows” that "B" blood is foreign (a person with "A" blood does not make any "B" blood cells). The antibodies in blood react with proteins and carbohydrates located on the exterior of foreign red blood cells, as shown in the drawings of "A", "B", "AB", and "O" blood types on the page.
D. Click on the back button in the red box at the top of the webpage. Click on the “How do you perform safe blood
transfusions?” tutorial and read the webpage. Complete the table below to show the safe types of blood transfusions.
Can receive blood from: Can give blood to:
F. Click on the back button in the red box at the top of the webpage.
Now you are ready to test your blood typing skills on some cyber‐patients! Click on the "Start Playing” box.
A. Read the information about the challenge. Proceed and follow the directions for the transfusion for that patient.
Record the patient’s blood type in the table below.
B. Click on “Next Mission”
Blood type # of Bags Needed Type(s) of Blood Given
Victim #1 (left side)
Victim #2 (middle)
Victim #3 (right side)
C. Mission Completed! How did you do? ________ red drops out of 5 drops
D. Conclusion questions:
What blood type is the universal donor (can be given to anyone)? (Circle)
A B AB O
What blood type is the universal recipient (can receive from anyone)? (Circle)
A B AB O
What blood type can be safely given to someone in an emergency if you didn’t know their blood type? (Circle)
A B AB O