1. 5.2 Incomplete & Codominance
2/15/18

2. Review: Complete dominance
What you guys already know
What have you been crossing?
RR v Rr

3. Codominance:
When both alleles of a gene are expressed in the phenotype of a heterozygote.
“co-ed”
Ex: RR-red x WW-white = RW- red with white spots

4. Codominance Genotype:
Cross RR x WW

5. Codominance Genotype R W

6. R W RW Codominance Genotype
What do you notice about the type of alleles in this Punnett square? R W RW
What is the probability of getting a Red Flower with white spots?
Co- no recessive alleles

7. Is there any chance of getting Homozygous RR Flower?

8. What would a cross of the offspring look like?RW
What would a cross of the offspring look like?

9. What would a cross of the offspring look like?RR RW WW
What would a cross of the offspring look like?

10. Can you write up the genotype from this phenotype?

11. Can you write up the genotype from this phenotype?
WW-White
BB-Black
BW-black and white

12. Codominance in Animals
Calico
Erminette
Roan

13. Remember making a baby?

14. “Co-Show”

15. Incomplete dominance:
When the heterozygous trait is a BLEND of the two homozygous phenotypes. 
Ex: RR-red x WW-white = RW-pink

16. Incomplete>>>not completely dominated
The dominant alleles do not completely take over the specific trait.
So we see a BLEND in the phenotype.

18. Incomplete dominance GenotypeB D

19. Incomplete dominance GenotypeB D BD

20. Now cross a platypus with a platypus.
BD x BD

21. Now cross a platypus with a platypus.
PD x PD B D BB BD DD

22. Baby example…..

23. Incomplete dominance in animals:
Palomino Horse

24. “Blend in”

25. The end!
Thanks guys