1. Blue people of Kentucky
Click ME

2. A little more on genetics…
4-4

3. Some vocabulary: Generations: P1 = Parent generation (1st in a cross)
F1 = First filial (offspring of P1)
F2 = Second filial (offspring of F1)
Locus = the location of a gene on a chromosome

4. Mendel’s Work Principle of Dominance and Recessiveness
Bred different phenotype plants
(ex. T= tall, t = short) by cross-pollination:
P Pure tall (TT) X Pure short (tt)
F1 All Tall (Tt, Tt)
F2 ¾ Tall (TT or Tt), ¼ Short (tt)

5. P Generation
F1 Generation
F2 Generation
Tall
Short
Tall
Tall
Tall
Tall
Tall
Short

6. He repeated this with 7 different traits and always got the same ratio in F2
Therefore: “Factors” (now called genes) control each trait.
Trait appearing in F1 is DOMINANT (ex. tall)
Trait reappearing in F2 is RECESSIVE (ex. short)

7. Punnett squares: Method used to predict the outcome of genetic crosses
One-Factor cross = one trait
Monohybrid cross– both parents heterozygous

8. Testcross
To figure out the Genotype of a parent, cross with a homozygous recessive parent and analyze offspring.
Ex. A man with free earlobes wants to know if he is homozygous or heterozygous. He marries an attached earlobed woman and has kids. The first kid he has displays attached earlobes
The man has thus found out that he is heterozygous