1. Genetics
History

2. The Lottery Directions: I am going to roll 6 dice…one at a time.
In order, write the numbers you think I will roll.

3. What were the odds of you winning?
Pretend these were the numbers you guessed.
What are the odds the 1st number is 5?
2nd number is 2?
3rd number is 6?
4th number is 5?
5th number is 1?
6th number is 3?
How do you calculate the overall odds? 1 6 1 6 1 6 1 6 1 6 1 6 X X X X X 1
46,656
= %

4. What is Genetics? Genetics: Study of heredity
Heredity: passing of traits from parent to child
Gregor Mendel
Austrian monk
Uncovered pattern for how traits can be passed from generation to generation

5. Mendel’s 7 traits studied

6. Mendel’s Experiment P Generation: F1 Generation:
Male: purple flowers
Female: Purple flowers
F1 Generation:
100% purple
Learned? Traits are inherited from parents
male
female
F1 Generation

7. Mendel’s Experiment P Generation: F1 Generation: Male: white flowers
Female: white flowers
F1 Generation:
100% white
male
female
F1 Generation

8. Mendel’s Experiment P Generation: F1 Generation: Learned?
Male: purple flowers
Female: White flowers
F1 Generation:
100% purple
Learned?
Some traits are dominant
Some traits are recessive
P Generation
male
female
F1 Generation

9. Mendel’s Experiment F1 Generation: F2 Generation: Learned?
Male: purple flowers
Female: Purple flowers
F2 Generation:
75% purple
25% white
Learned?
Offspring won’t always resemble the parents
Traits can skip generations
male
female
Remember… these had a white parent
F2 Generation
F1 Generation

10. Mendel’s 7 traits studied

11. Each trait had a 3:1 ratio. No way that can be a coincidence!

12. Chromosomes and Genes Genes are sections of DNA that create proteins:
located on chromosomes
inherited from parents
come in dominant & recessive forms known as alleles
Defined: Alternative form of a gene
Ex: Flower color
Purple allele (dominant)
White (recessive)
Letters used to abbreviate alleles
Dominant Allele = Capital letter
Recessive Allele = Lowercase letter

13. Common Vocabulary
Genotype: genetic make-up of an organism (combination of two alleles)
Homozygous Dominant (purebred): combination of 2 dominant alleles
Gene for dominant purple flowers
Gene for dominant purple flowers P P
Homozygous dominant
allele

14. Common Vocabulary p p Genotype: combination of two alleles
Gene for recessive white flowers
Gene for recessive white flowers
Genotype: combination of two alleles
Homozygous Dominant (purebred): combination of 2 dominant alleles
Homozygous Recessive (purebred): combination of 2 recessive alleles p p
Homozygous recessive
allele

15. Common Vocabulary P p Genotype: combination of two alleles
Gene for dominant purple flowers
Gene for recessive white flowers
Genotype: combination of two alleles
Homozygous Dominant (purebred): combination of 2 dominant alleles
Homozygous Recessive (purebred): combination of 2 recessive alleles
Heterozygous (hybrid): Combination of 1 dominant, 1 recessive allele P p
Heterozygous
allele

16. pp Common Vocabulary PP Pp Genotype: combination of two alleles
Homozygous Dominant (purebred): combination of 2 dominant alleles
Homozygous Recessive (purebred): combination of 2 recessive alleles
Heterozygous (hybrid): Combination of 1 dominant, 1 recessive allele
Phenotype: Physical expression of the gene PP
Phenotype:
PURPLE Pp
Phenotype: pp
white

17. 30 Seconds: Discuss with your neighbor:
Choices: YY
Tall Yy SS yY gg
Smooth
Green TT
Dwarf
Which choice(s) are examples genotypes?

18. 30 Seconds: Discuss with your neighbor:
Choices: YY
Tall Yy SS yY gg
Smooth
Green TT
Dwarf
Which choice(s) are examples heterozygous genotypes?

19. 30 Seconds: Discuss with your neighbor:
Choices: YY
Tall Yy SS yY gg
Smooth
Green TT
Dwarf
Which choice(s) are examples phenotypes?

20. 30 Seconds: Discuss with your neighbor:
Choices: YY
Tall Yy SS yY gg
Smooth
Green TT
Dwarf
Which choice(s) are examples of hybrid genotypes ?

21. 30 Seconds: Discuss with your neighbor:
Choices: YY
Tall Yy SS yY gg
Smooth
Green TT
Dwarf
Which choice(s) are examples of purebred genotypes?

23. Punnett Squares p p P P P P P P 100% p p p p
Homozygous dominant
Homozygous recessive
Defined: Genetics tools used to predict offspring probability
Setting Up Punnett Squares:
1) Parent genotypes on outside of the squares
2) Simply fill in each square
3) Inside squares represent the possible offspring genotypes
Probability of growing purple flowers? p p P P P p P p P p P p
100%

24. P p P P P P p P p p p p 1) List the genotypes. 1 PP, 2Pp, 1pp
1 minute: Cross a heterozygous purple (Pp) plant with another heterozygous purple (Pp) plant P
1) List the genotypes.
2) List the phenotypes.
3) What is the probability of having a white plant? p
1 PP, 2Pp, 1pp P P P P p
3 purple, 1 white P p p p p
25%

25. Autosomal Recessive InheritanceHh Hh
Autosome: Non-sex chromosome
Autosomal disorders are caused by genes found on the non-sex chromosomes
ex: Sickle cell = chromosome #11
ex: Cystic fibrosis = chromosome #7
Sufferers must inherit 2 recessive alleles to have the disease
H = healthy
h = disease H H h H h h
healthy
Healthy (carrier)
disease

26. 1 Minute: Maria is a heterozygous healthy (Hh) female and Jeff suffers from recessive cystic fibrosis (hh). h h
Key
H = healthy
h = cystic fibrosis H H h H h h h h h h
1) Probability of having a healthy child? _________
2) Probability of having a homozygous dominant child? ________
50% 0%

27. Review 1) How are dominant alleles expressed? Recessive?
2) Which of the following are genotypes? Phenotypes? Heterozygous genotypes? Hybrid?
TT Green yY Pp Purple gg Smooth
3) Genes may often be found in two forms (dominant and recessive). What are these alternate forms of a gene called?
4) Genes are segments of DNA found on _______________.
5) If item A is found in a 1:2 ratio compared to item B, what percentage is item A?
6) Cross a heterozygous tall with a homozygous recessive short pea plant.
List the genotypes in a Punnett square.
What’s the probability of growing a tall plant?
What’s the probability of growing a homozygous dominant plant?
What’s the probability of growing a homozygous recessive plant?