1. Beyond Dominant and Recessive
Non-Mendelian Inheritance
Chapter 10-3 (eye book)

2. ?
This means traits that don’t fit Mendel’s patterns of inheritance

3. Co - Dominance In co dominance, there are three phenotypes.
For this type of inheritance, there are two dominant traits.
This time, both dominant traits show in the heterozygous phenotype
For example: The two dominant traits of this type of fowl are white and black. The heterozygous phenotype appears speckled

4. Red = RR Stripes = RW White = WW
Co Dominance
The way we write alleles for this type of inheritance is with two different capital letters.
Each dominant trait gets its own letter
The heterozygous genotype gets both capital letters
Red = RR Stripes = RW White = WW

5. Practice Look at all the cows. What are all the phenotypes?
Which two traits are dominant, which is the mixed trait?
What notation will you use to represent…
The brown cow?
The white cow?
The speckled? BB WW BW

6. Incomplete Dominance (Also called – Intermediate inheritance)
In incomplete dominance, there are three phenotypes. The heterozygous phenotype is halfway in between the two other phenotypes
This is referred to as blending

7. Incomplete Dominance (Also called – Intermediate inheritance)
Since one phenotype is not dominant over the other, the homozygous phenotypes are both considered dominant.
Red = Dominant Pink = Blended White = Dominant

8. Incomplete Dominance (Also called – Intermediate inheritance)
The way we write alleles for this type of inheritance is with letters and superscripts.
We pick one letter to represent the trait
(ex – C for color)
We use superscripts to represent the expression of the trait
(ex – two different capital letters, for each dominant trait)
Red = CRCR Pink = CRCW White = CWCW

9. Practice CBCB CRCR CRCB
Look at all the fish. What are all the phenotypes?
Which two traits are dominant, which is the blended trait?
What notation will you use to represent…
The blue fish?
The red fish?
The purple fish?
CBCB
CRCR
CRCB

10. When an organism with a particular genotype does not survive
Lethal Allele
When an organism with a particular genotype does not survive
Example: Mexican Hairless Dogs
Dogs with the genotype HH do not develop and are never born. The resulting phenotype ratio is 2 hairless : 1 with hair H HH h hh Hh

11. Lethal Allele This is like Mendelian genetics because:
There are only two phenotypes
We use the same letter in capital and lower case
This is different than Mendelian genetics because:
You never get a 3:1 ratio – you get a 2:1 ratio instead

12. Multiple Alleles Some traits have more than two possible alleles.
Organisms still get two alleles, one from each parent
This increases the number of possible genotypes and phenotypes

13. Multiple Alleles
Human blood type is a good example of a trait with multiple alleles.
There are 4 different blood types: A, B, AB or O, which refer to a specific carbohydrate on the red blood cells
Phenotype (Blood type)
Genotype O
IOIO A
IAIA or IAIO B
IBIB or IBIO AB
IAIB

14. Copy this flowchart into your notes!!!
Start
3 phenotypes
2 phenotypes
Blending
Both traits show
2:1 ratio
All other ratios
Incomplete Dominance
Co-dominance
Lethal
Mendelian

15. What type of inheritance is shown?
White Horses
Brown Horses
Tan Horses
What type of inheritance is shown?
What gene symbols (letters) should you use to represent each phenotype?
3. What parent cross led to this population?
Prove it with a Punnett Square
All Tan Horses

16. What type of inheritance is shown?
brown puppies
Brindle (striped tan and brown) puppies
Tan puppies
What type of inheritance is shown?
What gene symbols (letters) should you use to represent each phenotype?
What parent cross led to this population?
Prove it with a Punnett Square
Half tan puppies and half brindle puppies

17. More Practice 100% white fish B) 100% red fish C) 66% red fish &
1. Mode of Inheritance
2. Gene Symbol (Letters) for each phenotype
3. Parent cross that gave us population A)
B) C)

19. Warm Up 1. What type of inheritance is shown? all three have the same:
Population 3 – 50% Red fish and 50% striped fish
Population 1 – 100% White fish
Population 2 – 100% Striped fish
1. What type of inheritance is shown? all three have the same:
( Mendelian / Incomplete dominance / Co-dominance / Lethal)
(Use your flow chart from yesterday to find out!!!)
What are the three phenotypes present?
(Look at the fish, and write down the three types you see)
3. What gene symbols (letters) should you use to represent each phenotype?
(Use your notes from yesterday to find out!!!)
4. What are the genotypes of the fish in each population?
(Match your answer from #3 to each population of fish)

20. MOI Table: Mendelian and Lethal Parental Crosses:
Non Mendelian Parental Crosses:
RR x RR RR x Rr RR x rr
Rr x Rr Rr x rr rr x rr
RR x RR RR x RW RR x WW
RW x RW RW x WW WW x WW
CWCW x CWCW CWCW x CWCR, CWCW x CRCR
CWCR x CWCR CWCR X CRCR CRCR X CRCR
NOTE – All Examples are for Red and White…you can use ANY letters