2. SMATH #14 -Cans project widely known as Tokyo underground flood tunnels is the networks of tunnels 6.4 kilometers (four miles) long built deep under the ground in the Tokyo suburbs. All this infrastructure is dedicated to prevent flooding when Tokyo metropolitan area rivers are overfilling during the rain seasons or in case of typhoons.

3. Introduction to Genetics Notes CH 11 Go to Section:

4. Introductory Vocabulary 1. Character: inheritable feature of an organism a.Example of characters in pea plants: Plant height, flower color, seed color, seed shape 2. Trait: variation in an inheritable feature Slide # 2 CharacterTraits HeightTall or Short Flower ColorPurple or White Seed ColorYellow or Green Seed ShapeRound or Wrinkled

5. Introductory Vocabulary 3. Heredity: transfer of traits from parent to offspring a. Inherited traits: traits received from parents b. Acquired traits: traits done to an organism that alter the appearance of the organism 4. Genetics: study of heredity 5. Pure breeding: producing same traits each generation 6. Hybrid: offspring from mating 2 different purebreds Slide # 3 Character: Stem height Traits: Tall or dwarf

6. Gregor Mendel: The Father of Genetics 1. Gregor Mendel: 1822-1884 Austrian monk a.Did genetics (breeding) experiments on garden pea plants. b.1866: Published paper on experiments Slide # 4 Gregor Mendel

7. Gregor J. Mendel, O.S.A., experimental garden (35x7 meters) in the grounds of the Augustinian Monastery in Old Brno. Its appearance before 1922. Courtesy of Villanova University Archives. The Monastery Garden with the greenhouse which Gregor J. Mendel, O.S.A., had built in 1870. Its appearance before 1902. Courtesy of Villanova University Archives. The Monastery Garden: Eight Years of Pea Experiments

8. Why Mendel Chose Pea Plants 1.Mendel chose pea plants for several reasons a.Grow quickly; grow many generations in short time b.Produce many offspring c.Have distinct traits Tall or dwarf Yellow or green seeds d.Could strictly control pollination Slide # 5 Brushed pollen from a 2 nd flower onto carpel (holds eggs) of 1 st flower Cut stamens (holds pollen) off of one flower Carpel develops into a pea pod.

9. Experiments with Pea Plants The distinct “either or“ traits. Seed shape (Smooth or wrinkled)

11. Mendel’s Experiment 1. Began with pure breeding parents. 2. All traits were the same in BOTH plants EXCEPT the trait being crossed. 3. All F 1 generation flowers (first generation) had purple flowers – it appeared as though white trait was lost! Slide # 6 Purple Flowers X White Flowers 4. Allowed 2 F 1 ’s to self pollinate. In F 2 generation, Mendel counted 705 purple flowered plants and 224 white flowered plants. (3 purple:1 white ratio) 5. The white flower trait was not lost; it was masked by the purple flower trait!

12. Question: What were the offspring of this P cross between a white and a purple flowering pea plant? The F 1 generation plants all had purple flowers. Question: What happens when the F 1 generation of pea plants are allowed to self- fertilize? The white trait reappeared! Question: What was the ratio for purple to white flowering plants in the F 2 generation? 3 purple :1 white

13. Seed Shape Flower Position Seed Coat Color Seed Color Pod Color Plant Height Pod Shape Round Wrinkled Round Yellow Green Gray White Smooth Constricted Green Yellow Axial Terminal Tall Short Yellow Gray Smooth Green Axial Tall Go to Section: Only one trait showed up in F 1 ’s; & both traits appeared in F 2 ’s at a 3:1 ratio. Mendel Found a Similar Pattern in Other Traits Slide # 7 F1F1 P

14. Conclusions made by Mendel: 1. Each parent MUST contribute one gene for each trait to the offspring. –Evidence: F 2 ’s had white flowers (present but hidden in F 1 generation.) 2. Each parent must have two copies of a gene; and can have two different versions of that gene called alleles at the same time. -- Evidence: F 2 ’s had white flowers both parents must have had at least one white allele!  Dominant: allele that is expressed when 1 or both are present (capital letter)  Recessive: allele that is masked by presence of dominant allele (lower case) a. The individual MUST have both recessive alleles to show the recessive trait Slide # 9 The F 1 purple flowering plants must have a second hidden gene for white flowers!

15. Alleles 1. Alleles: alternate forms of a gene or trait a. Parents may have two of the same alleles or two different alleles b. Homozygous: having 2 identical alleles c. Heterozygous: having 2 different alleles 2. Alleles are located on chromosomes This plant has 2 different alleles for the flower color character. Slide # 8 Every organism has two copies of the same gene. One copy came from MOM in her egg, the other gene copy came from DAD in his sperm. MOM DAD FROM Homologous Chromosomes

16. Homologous Chromosomes: -are similar gene carrying chromosomes from the opposite-sex parents.

17. Match these in your head, be ready to share. Gene Chromosome Homologous Pair Allele a. Threadlike structures made of DNA found in nucleus b. Unit of inheritance c. One form of a gene d. Two chromosomes that carry the same genes, but just different versions of those genes. Vocabulary Review

18. Mendel Solves the Genetics Puzzle 1.Mendel reasoned that each parent must have 2 possible alleles to contribute –Genotype: the alleles the organism has (two letters) –Phenotype: physical appearance of an organism 2.Mendel reasoned that the two alleles separated when gametes (sex cells like eggs) formed. 3.Mendel also reasoned that the alleles paired up again during fertilization (joining of egg &sperm) Genotypes: PP x pp Gametes: P ~ p Fertilization: Pp Genotype of F1: All Pp Slide # 10 Phenotype of F1: All Purple Phenotypes: Purple & White Purebred Hybrid

19. To show possible outcomes of genes the new generation will have We use: Gene diagrams or Punnett Squares

20. Gene Diagram – Flower color Alleles- P = Purple flower p = White flower All genes occur in pairs – so 2 alleles affect a characteristic – possible combinations are; genotypes PP Pppp PhenotypesPURPLE PURPLE WHITE

21. Gene Diagram – Flower color Malefemale Pp parent gamete P p P p Offspring genotype PP Pp pp Phenotype Purple White Purple Purple 3 purple : 1 white

22. Punnett Square Another method of showing crosses

23. 1. Determine what the alleles are. P=purple p=white 2.Parent genotypes are determined. --Both are Pp 3.Parent’s possible gametes are determined and placed one next to -or above each box. Pp Purple male Pp purple female Pp P p Complete the Cross PP Pp pp 3 purple and 1 white offspring 3:1 chance with these parents Punnett Square

24. Why the White Flowers Reappeared in the F 2 ’s Slide # 11 Genotype of F1: Pp x Pp Gametes: ½ P ½ P ½ p½ p F 2 Genotypes: 1 PP: 2 Pp: 1 pp F 2 Phenotypes: 3 Purple : 1 White

25. In Summary, Mendel’s Work Showed: 1.Each parent contributes one allele for each trait. 2.The two alleles of each trait separate from each other when gametes form (in meiosis) and pair up again during fertilization. 3.Male’s (sperm) and female’s (egg) contribute equally. 4.Acquired traits are not inherited.