1. Complex Inheritance Patterns
Polygenic Inheritance
Incomplete Dominance
Codominance
Environmental Factors

2. Heredity Genetics Heredity Study of GENES Study of
INHERITANCE PATTERNS
Passing of traits from
parents to offspring

3. Types of Complex Inheritance
Polygenic
Polygon: Multiple sides
Polygamy: Multiple marriages
Polytheism: Multiple gods
Polygenic: Multiple GENES
Incomplete Dominance
Codominance
Environmental Factors

4. Polygenic Inheritance
Multiple alleles (more than two options)
Genes spread over different locations or chromosomes
MANY different combinations and mixes
Examples:
Hair color
Eye color
Skin color
Degrees of extremes
(Dark to light, etc)

5. Incomplete Dominance MIXING Snapdragons: Red (R1) White(R2) Pink(R1R2)

6. Hair Type Straight Hair: Homozygous: Incomplete Dominant
Curly Hair: Homozygous: Incomplete Dominant
Wavy Hair: Heterozygous: A mix (Straight and Curly)

7. Environmental Factors
Some genes are only expressed under certain ENVIRONMENTAL CONDITIONS
Hydrangea Arctic Fox

8. Gender Determination Alligators, Tortoises and Turtles EXAMPLE:
Temperature changes the gender of offspring!
EXAMPLE:
Female if Hot
Male if Cold

9. Codominance Multiple alleles are DOMINANT over others Blood Type:
Dominant Types: A and B
Recessive Types: O
AA or AO=Type A
BB or BO=Type B
AB=Type AB
OO=Type O

10. http://www. google. com/imgres

11. Rh+ and Rh- Simple dominance and recessiveness
Rh+ is the DOMINANT trait (R)
Rh- is the RECESSIVE trait (r)
+ (Positive) simply means you carry Rh factor
Genotype
Phenotype
RR (++)
Positive
Rr (+-)
Rr (--)
negative

12. Want to know your blood type?
Legally, we can’t do the lab anymore 
BUT…you can find out by Donating Blood 
Here’s an example though…
My blood type is O (I’m a universal donor)
My brother is AB (He’s a universal acceptor)
What are my parents?
(Let’s do this on the board…it’ll be easier)