1. Heredity and Genetics

2. What makes you, you?

3. Learned vs. Inherited

4. Learned behaviors
Table manners
How to throw a ball

5. Inherited
Eye color
Curly hair
Height

6. Heredity
The passing of traits from parents to offspring.

7. Characteristics vs. Traits
Characteristic- a feature that has different forms in a population
Such as hair color (general)
Trait- different forms of the characteristics
Such as black hair (specific)

8. History of Genetics Gregor Mendel- the father of modern genetics
Studied pea plants
Why?
Fast growing
Able to cross pollinate and self-pollinate

9. Vocabulary
Cross pollination: pollen from one plant fertilizes another plant. Self-pollination: pollen from flower fertilizes itself True-breeding plant: a plant, that when it self pollinates, its offspring will have the same traits. “Pure” Hybrid: an offspring of two different parents

10. Mendel’s First Experiment
Mendel crossed (cross pollinated) true-breeding purple flowered pea plant with a true-breeding white pea plant. The offspring are called first generation (F1).

11. All of the pea plants in the first generation had purple flowers.

12. Mendel got similar results each time, one trait was always present in the first generation and the other trait seemed to disappear. Mendel called the trait that appeared the Dominate Trait. (shown as a capital letter) The trait that does not express itself is called the Recessive Trait. (shown as a lower case letter)

13. Mendel’s Second Experiment
Mendel then allowed the F1 generation plants to self-pollinate, producing an F2 generation.
Some of the F2 generation plants were white.

15. Mendel noticed that the ratio of dominant (purple) plants to recessive (white) plants was 3:1
His results could only be explained if each plant had 2 sets of instructions, one from each parent.

16. Each parent gives a set of instructions called alleles
Each parent gives a set of instructions called alleles. Two alleles make up a genotype (gene). Alleles are shown with either a capital letter (dominant) or a lower case letter (recessive).

17. Example
B b Bb allele allele genotype

18. Vocabulary Genotype: both inherited alleles (Hh, AA, ff).
Homozygous: gene with two dominant or two recessive alleles (BB, dd). True-breeding.
Heterozygous: gene with one dominant and one recessive allele (Gg, pP). Hybrid.
Phenotype: the outward expression of the genotype. What the genotype would look like, example: red hair.

19. Punnett Squares
a diagram that is used to predict the probability that a given trait will be expressed.

20. Mendel’s Experiment P=purple p=white
PPxpp p

21. P=purple p=white
PpxPp p

22. What needs to happen for a recessive trait to appear?
The genotype has to be homozygous recessive.
Two lower case letters

24. Incomplete Dominance
Both alleles are expressed, resulting in a combined phenotype
Example: R = red W = white
RR x WW

25. Incomplete Dominance

26. Sex Chromosomes
Males XY
Females XX