Fr. Gregor Mendel
Father of Genetics1822 - 1884
Pre-Mendelian Ideas on Inheritance
• Blending
• Homunculus
Homunculus
Why was Mendel Successful?
1. Good Research Organism (pea plant)
* Small, easy to grow in large numbers
* short life cycle could test several generations
* Could cross or self-pollinate
Could cross or self-pollinate(Why was this important????)
Why was Mendel Successful?
1. Good Research Organism (pea plant)
* Small, easy to grow in large numbers
* short life cycle could test several generations
* Could cross or self-pollinate
* Were “politically correct” (Explain!)
Why was Mendel Successful?
1. Good Research Organism (pea plant)
2. Had good math/statistical background
3. Picked good pairs of traits to study:ex: Tall/shortex: (find for HW!)
Mendel’s Experiments
Experiment #1
• Created “pure breeding” tall plants
• Created “pure breeding” short plants
Experiment #1 (cont)Crossed “pure” tall x “pure” short
Experiment #1 (cont)
Crossed two F1 plants (Monohybrid Cross!)
Now we know….
Now we know….
Mendel’s Laws
• Law/Principle of Dominance
• Law/Principle of Segregation
• Principle of Independent Assortment
figure 13-04_02