1. Set up Cornell Notes on pg. 85 Topic: 7.2 Patterns of Inheritance
Essential Questions:
Why might polygenic traits vary more in phenotype than do single-gene traits?
How is codominance the same as having no dominant and recessive relationship at all between 2 alleles?
7.2 Patterns of Inheritance
2.1 Atoms, Ions, and Molecules
Why might polygenic traits vary more in phenotype than do single-gene traits?
How is codominance the same as having no dominant and recessive relationship at all between 2 alleles?
KEY CONCEPT Phenotype is affected by many different factors.

2. 84
Incomplete Dominance
Codominance

3. KEY CONCEPT Phenotype is affected by many different factors.

4. + What are our possible outcomes for this combination of flower color?
What if red nor white was dominant or recessive to one another?

5. In incomplete dominance, neither allele is completely dominant nor completely recessive.
They are a BLEND of each other
Ex: red+white rose= pink rose
BB RR BR

6. Heterozygous phenotype is intermediate between the two homozygous phenotypes
Homozygous parental phenotypes not seen in F1 offspring
Steel blue betta fish
(BB)
Royal blue betta fish
(GB)
Green betta fish
(GG)

7. B B BR BR R BR BR R
Genotype:
Phenotype: BR
100% pink flowers

8. B R B R BB Red rose BR Pink rose BR Pink rose RR White rose Genotype:
BB, RR, BR
Phenotype:
25%= red flowers 50%= pink flowers 25%= white flowers

9. Codominant alleles will both be completely expressed.
Codominant alleles are neither dominant nor recessive.
Ex: multi-colored red and white rose
Ex: In humans, ABO blood type. (A, B, AB, O)

10. B B BR BR R BR BR R
Genotype:
Phenotype: BR
100% red and white flowers

11. B R BB BR B BR RR R Genotype: Phenotype: BB, BR, RR
25% red flowers, 50% red-white flowers, 25% white flowers

12. How to tell if we are asking you about incomplete dominance OR codominance..
The trick is to recognize when you are dealing with a question involving incomplete dominance.  There are two steps to this: 
1) Notice that the offspring is showing a 3rd phenotype.  The parents each have one, and the offspring are different from the parents. 
2) Notice that the trait in the offspring is a blend (mixing) of the parental traits.

13. Polygenic traits are produced by two or more genes.
Can produce a continuous range of colors
Ex: Skin color- 4-6 genes
Eye color- at least 3 genes

14. Sponge Bob Incomplete Dominance Worksheet