1. Gregor Mendel & Basic Genetic Principles

2. Who is Gregor Mendel? Austrian Monk that experimented with pea plants. He discovered the basic principles of genetics.

3. Pea Plants Pollination occurs easily within the flower. Relatively short life cycle (2-3 weeks). Have 7 characteristics with contrasting forms.

4. Pollination Movement of pollen between sexual parts of flowers. Self Pollination – pollination that occurs within one flower. Cross Pollination – movement of pollen from one flower to another.

6. 7 different traits of pea plants Seed shape – round/wrinkled Seed color – yellow/green Seed coat color – colored/white Pod shape – inflated/constricted Pod color – green/yellow Flower position – axial/terminal Stem length – long/short

7. Mendel’s 1 st Experiment Mendel created pure–bred pea plants of each characteristic. Ex. Tall/Short, Green seeds/Yellow seeds. He crossed these plants together (P1 or Parent generation). Offspring: ALL TALL! (F1 generation).

8. Mendel’s 1 st Law Law of Dominance When organisms with contrasting traits are crossed, only the Dominant trait appears in the offspring.

9. Mendel’s 2 nd Experiment Mendel took those F1 generation plants and crossed them. F2 generation results: 3 TALL, 1 SHORT = 3:1 phenotypic ratio. 1 TT, 2 Tt, 1 tt =1:2:1 genotypic ratio

11. Mendel’s 2 nd Law Law of Segregation Factors occur in pairs and separate during gamete formation only to recombine again during fertilization.

12. Vocabulary Dominant gene – gene that prevents the expression of another. Ex. Brown hair – represented with a capital B. Recessive gene – gene that is not expressed, it is usually hidden by a dominant gene. Ex. Blond hair – represented with a lower case b.

13. Allele – dominant and recessive forms of genes. Genotype – genetic makeup of an organism regarding its characteristics.(TT, Tt, tt) Phenotype – physical appearance of an organism. (Tall/Short)

14. Heterozygous – have 2 different alleles for a particular charateristic. (Ex. Tt = a heterozygous tall plant) Homozygous – have the same alleles for a particular characteristic. (Ex. TT = a homozygous tall plant & tt = a homozygous short plant) Hybrid – Common term for heterozygous. Ex. Tt

15. Monohybrid Cross – Cross between two parents that deals with only one trait. Dihybrid Cross – Cross between two parents dealing with two different traits. Incomplete dominance – Blending, when both traits express themselves. Sex linked traits – Involves genes that are located on the X chromosome.

16. Figure 10.13 figure 10-13.jpg

17. Mendel's law of independent assortment of alleles Alleles of different genes are assorted independently of one another during the formation of gametes. Mendel determined this law by crossing plants containing two different traits. (Ex. True breed round & yellow seeded plants (RRYY) with true breed wrinkled & green seeds (rryy)

18. Figure 10.7 figure 10-07.jpg