1. Mendelian Exceptions
Harry Potter Style

2. Inherited Traits
What types of inherited genetic traits are described in the Harry Potter series?

3. Inherited Traits
"All the Weasleys have red hair, freckles, and more children than they can afford." -- Draco Malfoy (Sorcerers Stone, Ch.6)
He was almost twice as tall as a normal man and at least five times as wide. (Sorcerer’s Stone, Ch.1)
Harry had a thin face, knobby knees, black hair, and bright green eyes. (Sorcerer’s Stone, Ch.1)
A pale boy with a pointed face and white-blond hair, Draco greatly resembled his father. His mother was blonde too... (Goblet of Fire, Ch.8)

4. Applying Genetics
What are some phenotypes (observable traits) described in the four excerpts from the Harry Potter books?
Freckles
Hair color
Eye color
Height

5. Applying Genetics A genetic trait can be described in two ways:
Phenotypes are observable traits resulting from how one’s genes are expressed. Ex., hair color, a talent, sickle cell disease, etc.
A Genotype consists of two letters that represent a gene’s allele pair that results in a phenotype.

6. Example: Red Hair Rr ====== brown hair rr ====== red hair
Red hair color is recessive to brown color. One way to describe the hair color alleles are:
Red hair = r (notes recessive red color)
Brown hair = R (notes dominant brown color)
Question: Using r (red hair) and R (brown hair) alleles, what possible genotypes of the allele pair are there?
Genotype (allele pair) Phenotype (appearance)
RR ====== brown hair
Rr ====== brown hair
rr ====== red hair

7. Rules of Inheritance
Some traits follow the simple rules of Mendelian inheritance of dominant and recessive genes.
Complex traits follow different patterns of inheritance that may involve multiples genes and other factors. For example,
Incomplete or blended dominance
Codominance
Multiple alleles
Sex linked
Polygenic Inheritance
Any guesses on what these terms may mean?

8. Incomplete Dominance
Incomplete dominance results in a phenotype that is a blend of a heterozygous allele pair. Ex., Red flower + White flower => Pink flower
If the dragons in Harry Potter have fire-power alleles F (strong fire) and F’ (no fire) that follow incomplete dominance, what are the phenotypes for the following dragon-fire genotypes?
Genotypes Phenotypes
FF strong fire
FF’ moderate fire (blended trait)
F’F’ no fire

9. Codominance
Codominance results in a phenotype that shows both traits of an allele pair. Ex., Brown cow + White cow => Brown & White Cow (both traits)
If merpeople have tail color alleles B (blue) and G (green) that follow the codominance inheritance rule, what are possible genotypes and phenotypes?
Genotypes Phenotypes BB blue tail GG green tail BG blue & green tail (both traits)

10. Multiple Alleles
Multiple alleles have more than 2 variations. Ex., human blood type has 3 different allele variants, A, B, and O
(Individuals are only able to hold 2 of them.)
Genotypes
Phenotypes
AA, AO
A blood type AB
AB blood type
BB, BO
B blood type OO
O blood type

11. Genotype for Blood Type
I and i used in genotype I used with A and B i used with O A and B are dominant over O: A and B are codominant Ex: Genotype: AA is IAIA

12. Multiple Alleles Govern Blood type: 2 traits- ABO blood type and Rh factor a. A and B alleles are co-dominant (neither one can mask the other), and o is recessive IB i IA IA IB i IB i IA

13. IV. Complex Inheritance of Human TraitsIB i IA
IAIB
IAi IA IB i
IAi
IBi IB i IA
IAIB
IAi
IBi ii

14. Sex Linked Traits
Sex determination Sex Chromosomes in humans: XX is female, XY is male
**Every new born has a 50% chance of being female and a 50% chance being male** X Y

15. Sex-linked Traits
traits carried on the sex chromosomes ; mostly on X-Chromosome b. leads to an unequal occurrence of the trait in the sexes e.g. hemophilia or color-blindness in humans e.g. eye color in fruit flies

16. Colorblind: X-linked trait
C- normal vision
c- colorblind
You must incorporate XX (mom) and XY (dad)
This is how to set it up:
(remember colorblindness is X-linked!)
Normal vision
Heterozygous
(carrier)
Colorblind
Female: XX
Male: XY

17. Punnett Square
Cross a female who is a carrier for colorblindness with a normal vision man.
Cross a normal vision woman (homozygous) with a colorblind man.

18. Hemophilia: X-linked recessive trait
Hemophilia is the inability for blood to clot
Your blood clots every time you get a papercut
H: normal clotting
h: hemophilia
Make a key for hemophilia:
Normal female: Normal Male:
Female Carrier: Can a man be a carrier?
Female with hemophilia: Male with:

19. Polygenic Inheritance
a. multiple genes coding for one trait b. leads to a spectrum of traits e.g. skin color and hair color in humans e.g. stem length in plants

20. Environmental Influences
both external and internal (including age)
1. There are external(temperature, nutrition, light) and Internal (hormones) influences on genetics.
2. Knowing the genotype at birth determines only the organism’s potential to develop and function.