1. Blood Type Inheritance and the Punnett Square

2. Blood Type Inheritance
Type O blood = oo (recessive)
Type B blood = BB (homozygous) or
Bo (heterozygous)
Type A blood = AA (homozygous)
Ao (heterozygous)
Type AB blood = AB

3. Terms to be familiar with
Homozygous = same letters (alleles)
Heterozygous = different letters (alleles)
Genotype = letters (inherit 1 from each parent)
Phenotype = physical appearance of trait (actual blood type)
Dominant = shows up; covers up recessive trait
Recessive = trait that can be masked

4. Punnett Square

5. Punnett Square
One parent’s genotype goes here
The other parent goes here

6. One parent’s genotype goes here
Punnett Square
One parent’s genotype goes here
Possible Offspring Genotypes Go Here
The other parent goes here

7. One parent’s genotype goes here
Punnett Square
One parent’s genotype goes here
Possible Offspring Genotypes Go Here
(25% chance)
The other parent goes here

8. Example
Jack and Jill get married and have a child. Jack is heterozygous for the blood Type A and Jill has type AB blood. What is the chance that they will have a baby with type B blood?

9. Punnett Square

10. Punnett Square drop and drag to fill in the squares
A o AA Ao AB Bo A B

11. Based on the Punnett Square, there is a 50% the child will type A blood, 25% the child will have type AB blood, and a 25% the child will have B blood.
A o AA Ao AB Bo A B

12. Example
Jack and Jill get married and have a child. Jack is heterozygous for the blood Type A and Jill has type AB blood. What is the chance that they will have a baby with type B blood? Based on the results on the previous slide, there is a 25% chance a child of Jack and Jill’s will have type B blood.

13. Example 2
Bonnie and Clyde are having a baby and they want to know if there is a chance that they can have a child with Type O blood. Bonnie is homozygous for type A blood and Clyde has type O blood. What did you find out?

14. Punnett Square

15. Punnett Square drop and drag to fill in the squares
o o Ao A

16. They will not have a child with Type O blood
They will not have a child with Type O blood. There children will only have type A blood (100% chance).
o o Ao A