Gregor Mendel (1822-1884) The Father of Genetics Mendelian Genetics 1/11/2019 Gregor Mendel (1822-1884) The Father of Genetics This has been modified from the original ppt Oct. 2011 copyright cmassengale

Gregor Johann Mendel Austrian monk Mendelian Genetics 1/11/2019 Gregor Johann Mendel Austrian monk Studied the inheritance of traits in pea plants Developed the laws of inheritance Mendel's work was not recognized until the turn of the 20th century

copyright cmassengale Mendelian Genetics 1/11/2019 Gregor Johann Mendel Between 1856 and 1863, Mendel cultivated and tested thousands of pea plants He found that the plants' offspring retained traits of the parents copyright cmassengale

Particulate Inheritance Mendelian Genetics 1/11/2019 Particulate Inheritance Mendel stated that physical traits are inherited as “particles” Mendel did not know that the “particles” were actually Chromosomes & DNA copyright cmassengale

Why Peas? Talk with your shoulder buddy for a minute and discuss why you think Mendel choose peas as his primary mode of experimenting!

copyright cmassengale Mendelian Genetics 1/11/2019 Why peas, Pisum sativum? Can be grown in a small area Produce lots of offspring Produce pure plants when allowed to self-pollinate several generations Can be artificially cross-pollinated copyright cmassengale

Science Humor

Mendel and His Peas Mendel tested 7 traits: Flower color Flower position Seed color Seed shape Pod shape Pod color Plant height http://www.fieldmuseum.org/exhibits/traveling_mendel.htm

Unit A : Chapter 1 : Section 1 Video Break… http://youtu.be/EvR_Sdm1orU Unit A : Chapter 1 : Section 1

Mendel and His Peas Mendel crossed flowers that were true-breeding for each characteristic. He crossed a purple (PP) flowered plant with a white (pp) flowered plant. (Parent Generation) http://biology.kenyon.edu/courses/biol114/KH_lecture_images/Mendel/Mendel.html

Mendel and His Peas Purple Parent (PP) The first generation (F1) of plants all had purple flowers. Where did the white color go?? White Parent (pp)   (Pp)    (Pp)    (Pp)

Mendel and His Peas Mendel took two of his first generation (F1 x F1) purple flowered plants and crossed them together. In the second generation (F2) he had 3 purple flowered plants, and 1 white flowered plant. Purple Parent (Pp) Purple Parent (Pp)    (PP)   (Pp)   (Pp)   (pp)

Mendel and His Peas Mendel noticed in the first generation, all of the white flowers seemed to disappear. He called this a recessive trait. The white color faded into the background at first, then it showed up in the next generation when he pollinated the flowers.

Mendel and His Peas The color (purple) that seemed to mask over the recessive color was named the dominant trait.

Mendel’s Conclusions… 1) Law of Independent Assortment – inheritance of one trait had NO EFFECT on the inheritance of another trait When he crossed two plants with different traits (flower color and pea shape) he found the inheritance of one trait did NOT influence the inheritance of the other Unit A : Chapter 1 : Section 1

Mendel’s Conclusions… 2) Law of Segregation – Alleles of a gene separate during meiosis and each gamete receives only one allele for each trait Unit A : Chapter 1 : Section 1

Unit A : Chapter 1 : Section 1 Top 5 Biology Song… http://youtu.be/2xpTz7SUbnc Unit A : Chapter 1 : Section 1