1. Introduction to Genetics

2. Objective: I can construct 2 examples of phenotype and genotype using Punnett squares
Warm Up: #1. List the stages of mitosis
#2. What is happening in this picture? What is it called?

3. Who was Gregor Mendel? He was known as the “FATHER OF GENETICS”
He discovered how traits were inherited
GENETICS- study of heredity
HEREDITY - the passing of traits from parents to offspring

4. Mendel’s Peas Mendel did his study on pea plants
Pea plants have many traits
( tall/short, purple flowers, white flowers)
Pea plants can be self-fertilized or cross fertilized

5. Generation
Parent Generation (P Generation): 1st organisms to be crossed
F1 Generation: Offspring of the parent generation
F2 Generation: Offspring of the F1 generation

6. Cross of pure breeding green + yellow pea plant
Parent generation is P generation. Green seed and yellow pea seed.
Seeds from First generation ( F1) All had yellow seeds.
Planted F1 and the Second Generations (F2) was a 3:1 ratio of yellow to green

7. Genes and Alleles
Mendel discovered that each trait is controlled by two factors (alleles)
Alleles: different forms of the same gene.
Genes-factors that determine your traits

8. Types of plants
1. True-breeding- produce offspring with only one form of a trait. *Individuals are homozygous, offspring are identical to parents.
2. Hybrids –offspring of true-breeding plants
Tall x short =Hybrid

9. Dominance Some traits are dominant over other
Tall x short = all tall offspring (hybrids)
*Tall is the dominant trait
* Short is recessive
Because yellow is dominant it is represented by Capital Y
Lowercase y for recessive

10. Homozygous: organism with two of the same alleles of that trait
Homozygous: organism with two of the same alleles of that trait. ( Purebred)
* YY yellow seed plant
* yy green plants
Heterozygous: organism with two different alleles. Yy, dominant trait will be observed
* Heterozygous organisms are called hybrids

11. Law of independent assortment
Allele pairs separate independently during gamete formation
Traits are passed to offspring independently of one another
Alleles for blue eyes and blonde hair are inherited separately from one another

12. Law of Segregation
Alleles for a trait separate when gametes are formed
Alleles are then randomly unites at fertilization

13. GENOTYPE: what genes, letter, the organism has ( TT, Tt, tt)
GENOTYPE: what genes, letter, the organism has ( TT, Tt, tt) * the plant with yellow seeds their genotype could be YY or Yy PHENOTYPE: what it looks like ( tall, or short) observable characteristics or outward expression of an allele pair

14. Monohybrid cross: a single trait. Dominant allele written first
Dihybrid Cross: 2 or more traits in the same plant (organism)
In peas: round seed(R ) are dominant to wrinkled seeds(r) and yellow seeds (Y) are dominant to green seeds (y)

15. Punnett Squares
To predict the possible offspring of 2 crosses between 2 known genotypes
- Easier to keep track of possible genotypes involved in a cross.

16. Probability
Chance of flipping heads is ? ½?