1. Genetics

2. Brown Eye Gene
Blue Eye Gene
Brown Eye Gene
Blue Eye Gene

3. What is an ALLELe? Different form/version of a gene
You inherited ONE ALLELE from each parent for each trait.
For example –
Gene = eye color
Allele = blue, hazel, brown, and green

4. Dominant vs. Recessive Alleles
Dominant allele hides the recessive allele.
The Dominant allele always shows/is visible
For example – hair color – brown is dominant to all other hair colors
EX: mom gave you the allele (gene) for brown hair. Dad gave you the allele for blonde hair.You will have what color hair?
Answer: Brown hair

5. Dominant vs. Recessive Alleles (Cont.)
Recessive allele is always hidden if a dominant allele is present.
You must inherit 2 recessive alleles for the trait to show up/become visible.
EX:– hair color – blonde is recessive to all other hair colors
mom has to give you the allele (gene) for blonde hair and dad gave you the allele for blonde hair, you will have blonde hair!

6. Writing Alleles? All alleles are assigned letters
Dominant allele=CAPITAL letters
B=(Brown eyes)
Recessive allele – lower case
b= (blonde eyes)

7. Two letters pair for each trait – one passed on from mom and one from dad
Using the letter B tell me what a person with brown hair would look like
BB_____
Bb_____
bb_____
Is this trait dominant or recessive?
DOMINANT
What if the person had blonde hair (recessive trait)? bb

8. How you get your traits?
Dimples are a dominant trait. Non dimples are recessive. If both parents have have dimples would all the kids have dimples?

9. Genotype vs. Phenotype Phenotype- physical trait
can be seen
Brown or blonde
Genotype- genetic makeup
Alleles inherited
(not seen BB, Bb)

10. Genotype/Phenotype Practice
Are the following genotype or phenotype
Hazel Eyes.
Phenotype BB
Genotype
Long Toes Rr
genotype Tt
Ear Hair
Phenotype Ff
Freckles
phenotype

11. Homozygous vs Heterozygous
PREFIXES:
HOMO=SAME alleles for a specific trait ( TT or tt)
HETERO=DIFFERENT alleles for a specific trait (Tt or Bb)

12. Practice-
1.) If you inherited the 2 alleles for blue eyes (1 from each parent), your phenotype is __________, your genotype is _____, and you’re _____ zygous.
2.) If you inherit the dominant allele for dimples from your dad, and the recessive for no dimples from your mom, your phenotype is ______, your genotype is _______, and you’re ____ zygous.

13. Practice Problems
Will the following plants be tall or short? T=tall and t=short Tt TT tt
Are the following plants homozygous or heterozygous?

14. What is the phenotype of the following plants? Tt TT tt
Practice
What is the phenotype of the following plants? Tt TT tt

15. Genotype codes for Phenotype.
P = Purple and p= white
Y = Yellow and y = green
R = Round and r = wrinkled
Genotype is RR, the Phenotype is ______.
Genotype is YY, the Phenotype is ______.
Genotype is pp, the Phenotype is ______.
Genotype is Rr, the phenotype is ______.
Genotype is Yy, the phenotype is ______.
Phenotype is wrinkled, the genotype is ____.
Phenotype is green, the genotype is _____.

16. Genotype codes for Phenotype.
P = Purple and p= white
Y = Yellow and y = green
R = Round and r = wrinkled
Genotype is RR, the Phenotype is ______.
Genotype is YY, the Phenotype is ______.
Genotype is pp, the Phenotype is ______.
Genotype is Rr, the phenotype is ______.
Genotype is Yy, the phenotype is ______.
Phenotype is wrinkled, the genotype is ____.
Phenotype is green, the genotype is _____.

17. C ______ d _______ e _______ F _______ f ______ v ______ P ______
. Write dom. For dominant or rec. for recessive next the letter.
A ______
C ______
d _______
e _______
F _______
f ______
v ______
P ______
m ______
M ______
Q _______
n ________
b ________
X ________
Y _________

18. AA _____ Bb ____ Cc ____ DD _____ eE _____ Ff ____ Gg ____ Hh ____
. Write Ho. for homozygous or He. for heterozygous.
AA _____
Bb ____
Cc ____
DD _____
eE _____
Ff ____
Gg ____
Hh ____
Kk ____
Mm ____
Nn ____
RR ____
Ss ____
NN ____

19. Write Ho. Dom if it is homozygous dominant, Ho. Rec
. Write Ho. Dom if it is homozygous dominant, Ho. Rec. if it is homozygous recessive or He if it is Heterozygous.
AA ____
BB ____
Cc ____
dd ____
FF ____
qq ____
SS ____
TT ____
VV ____
Tt ____
uu ____
WW ____
ii ______
xx ____
bb ____

21. Zygote- 1 allele from each parent
Law of Segregation
What is segregation
separation of allele pairs
When does this occur?
During meiosis (formation of sex cells)
Why do they segregate?
So each gamete only carries a single copy of each gene.
B= Brown eyes
b= Blue eyes
Zygote- 1 allele from each parent
segregation
segregation B b Bb bb b b b b
Baby- blue eyes
Dad- Brown eyes
Mom- Blue eyes

22. Zygote- 1 allele from each parent
B= Brown eyes
b= Blue eyes
Zygote- 1 allele from each parent
segregation
segregation B b Bb bb b b b b
Baby- blue eyes
Dad- Brown eyes
Mom- Blue eyes

23. Meiosis Video

25. Law of Independent Assortment
What is independent assortment?
Genes/alleles separate independently during meiosis.
Genes don’t influence inheritance of other genes
(Inheriting blue eyes doesn’t mean you’ll automatically inherit blonde hair)
Seed color does not influence seed shape
Dihybrid Crosses (2 trait punnet square) demonstrates this law.

28. More on genetics….to be continued.