1. How I discovered genetics
Gregor Mendel
How I discovered genetics

2. My Life 1822 – born in rural Czech Republic 1843 – joined monastery
1851 – 2 years study in Vienna – Physics and math
– taught school and grew a garden

3. The basics
Before Mendel, people thought inheritance was the product of a mixing or blending of parental traits
Ex: black hair + blond hair = brown hair
P = Parent generation
F1 = First offspring generation
F2 = Second offspring generation

4. Mendel’s Experiments
Used garden peas to develop the principle of genetics.
Looked at 7 different traits
Spent two years preparing homozygous P generation plants
Cross pollinated 2 different homozygous strains of P generation and found that the F1 generation exhibited only ONE of the 2 parental traits (ex. Tall + Short = only Tall)

5. Mendel’s pea characteristics

6. More experiment
Then, crossed F1 generation plants and found that ¾ of the F2 generation showed the F1 phenotype and ¼ showed the the hidden trait from the P generation
This 3:1 ratio is called the Mendelian Ratio
Tests took 8 years to complete with 2 full time assistants, tested 30,000 plants
Confirmed results by testing on corn, flowers, other plants for 4 years.

7. Experiment

8. Conclusions
Genes – individual factors that do not blend, made up of DNA found on chromosomes
Principle of Dominance – some traits are stronger than others, dominant genes express over recessive ones
Law of Segregation – the two alleles from each parent are segregated or split apart when the gametes form
Law of Independent Assortment – One trait does not necessarily affect another trait (ex: seed color does not determine height)