The History Of Genetics: Gregor Mendel and his Peas

1. The History Of Genetics: Gregor Mendel and his Peas

2. The results of Mendel’s studies were so important that he is considered: Father of Genetics

3. WHY PEAS? • Structure of the pea flowers • Presence of distinctive traits • Rapid reproduction cycle • Grow quickly • Produce large number of offspring • Cheap and easy to grow and maintain • Pea plants normally self-pollinate but can cross-pollinate if the anthers (the boy parts) are removed when the flower is young Anther-holds male gametes stigma filament style petal Ovary (holds female gametes-eggs) sepal

4. Self Pollination • Self-pollination female and male gametes (egg & pollen) from the same plant form a zygote example: this is how plants normally go about their business

5. PurpleFlower Petals form a tent over the stigma and anthers Pollen is trapped inside pollen * Anther (boy part) Stigma (girl part) Pollen (gamete from the boy part) goes to the stigma ( the girl part) of the same flower fertilizes the female gamete

6. Cross-pollination • Cross-pollinationfemale and male gametes from two different plants form a zygote example: Mendel “painted” pollen from one plant onto the stigma of another plant, or insects transfer pollen from one plant to another

7. Mendel cut off the anthers so the plant does not produce its own pollen. Mendel painted pollen from another plant onto the stigma of the flower

8. Mendel studied characteristics in the parents and offspring of pea plants. The plants displayed several easily-observed characters in one of two contrasting traits or forms

9. Mendel studied characteristics in the parents and offspring of pea plants. The plants displayed several easily-observed characters in one of two contrasting traits or forms yellow green ATGCCAGCTACC Different sequences CTGACCGTACCG

10. Mendel observed that there were two different types of pea plants

11. Mendel performed his experiments with great patience and precision. He kept careful records. Mendel’s work spanned 10 years and involved over 280 genetic crosses producing some 28,000 pea plants. • Mendel was trained in mathematics and used his background in probability to analyze the results of his crosses.

12. Describe (briefly) the experiments that Gregor Mendel set up. • Mendel set up crosses with pea plants to see how their traits were passed down from generation to generation

13. Why were pea plants an ideal choice for Mendel’s experiments? (give at least three reasons) • Structure of the pea flowers • Presence of distinctive traits • Rapid reproduction cycle • Grow quickly • Produce large number of offspring • Cheap and easy to grow and maintain • Pea plants normally self-pollinate but can cross-pollinate too

14. What were some the traits he observed? What were the different alleles for these traits?