1. Complete, Incomplete & Co-Dominance
Genetics After Mendel
Complete, Incomplete & Co-Dominance

2. Complete Dominance (Mendel)
Review:
Alleles are what code for physical traits
Some alleles are dominant over other alleles (recessive), and therefore suppress their expression
An individual has 3 possible genotypes:
homozygous dominant : heterozygous : homozygous recessive
And 2 possible phenotypes:
Dominant : Recessive

3. Examples of Complete Dominance
Genotypes
Patterns in F1 and F2 generations?

4. Examples of Complete Dominance
F3 generation Anything is possible!

5. Incomplete Dominance
Incomplete dominance is a form of intermediate inheritance in which one allele for a specific trait is not completely dominant over the other allele.
This results in a third phenotype in which the expressed physical trait is a combination of the dominant and recessive phenotypes.

6. Examples of Incomplete Dominance
Let R= Red
Let W= White
Offspring phenotype
are a blend of the
two alleles;
genotype?
Patterns in F1
and F2 generation?

7. Codominance
A condition in which both alleles of a gene pair in a heterozygote are fully expressed, with neither one being dominant or recessive to the other
Similar to incomplete
dominance as it results
in three phenotypes and
three genotypes

8. Examples of CodominanceCb Cr
CrCb
Let Cb= blue colour
Let Cr= red colour
Would there be any patterns in the F1 and F2 generation?

9. Examples of Codominance
Shorthorn Cattle