11.2 Applying Mendel’s Principles

1. January 10, 2014 11.2 Applying Mendel’s Principles

2. Plan for Jan. 10 • Check up #1: Mendel’s Genetics • Notes: Dihybrid Cross; independent assortment • Analyzing Inheritance Activity

3. Check Up #1 Do: You may refer to your class notes only. Put: Write your answers in the space provided. Finish By: You have 10 minutes. When Done: Turn your paper in. Work silently on something of your choosing.

4. How do alleles segregate when there is more than one gene? Segregation with One Trait Does the segregation of one pair of alleles affect another pair? Mendel followed two different genes as they passed from one generation to the next.

5. Dihybrid Cross • I can construct, complete, and interpret a Punnett square to predict traits for a dihybrid cross.

6. Make a Punnett Square--Dihybrid Cross-- 1. Start with the parents. Heterozygous for size AND Heterozygous for pod color Green dominant allele Yellow recessive allele • Tall dominant allele • Short recessive allele Tt Gg Tt Gg

7. Make a Punnett Square--Dihybrid Cross-- Step 2: Determine which alleles would be found in all possible gametes each parent would produce: T G TG T g Tg TtGg TtGg t G tG t g tg The allelessegregateduring gamete formation. Each gamete has one allele for size and one for pod color.

8. Make a Punnett Square--Dihybrid Cross-- Step 3: Line up the genotypes in a 4 x 4 grid:

9. Make a Punnett Square--Dihybrid Cross-- Step 4: write out the new genotypes:

10. Make a Punnett Square--Dihybrid Cross-- Step 5: Figure out the results: The square color represents pod color. Alleles written in red indicate tall plants and alleles written in black indicate short plants.

11. Make a Punnett Square--Dihybrid Cross-- What percent of offspring will be tall with green pods?: The Punnett square predictsthat 56% (9/16x100) of offspring will be tall with green pods. 9 tall/green 3 tall/yellow 3 short/green 1 short/yellow 16 offspring

12. Collaborative Group Assignments

13. Collaborative Group Assignments

15. Genetic Probability Activity Do: Working in collaborative pairs/triads you will complete the probability activity. Put: Each student completes their own paper but uses the same data. Finish By: You have 20 minutes. When Done: Get your paper stamped and file it in your notebook.

16. Plan for Jan. 14 • Review Check-up #1 • Discuss “Analyzing Inheritance Activity” and Genetics Probability • Wrap-up Mendel’s Genetics

17. #2 Punnett Square for RrYy x RrYy Ups and Downs of Probability 9 round, yellow 3 round, green 3 wrinkled, yellow 1 wrinkled, green 16 offspring total

18. #3. What is the predicted outcome of phenotypes for the cross in #2? #4. Is your experimental outcome the same as the predicted outcome? Explain. #5. Experiment modifications? What and why?

19. Predicted versus Experimental Phenotypes Period 4 Class Results

20. Predicted Outcomes for Phenotypes (P6): Period 6 Class Results

21. Genetic Probability • Probabilityis the likelihood that a particular event will occur. • Probability values are always between 0 and 1 • Probability of 0—event never happens • Probability of 1—event always happens Example: probability of flipping a coin and getting tails is ½ or 50%

22. Genetic Probability If you flip a coin three times in a row, what is the probability that it will land heads up every time? 1/2 Each toss is an independent event. Multiply probabilities: ½ x ½ x ½ = 1/8 1/2 1/2

23. Genetic Probability In genetics it is usually more complex. A more complex event is simply a combination of simple events.

24. The Two-Factor Cross: F1 Does the gene that determines seed shape affect the gene for seed color? Mendel crossed true-breeding plants that produced only round yellow peas with plants that produced wrinkled green peas.

25. The Two-Factor Cross: F1 • The round yellow peas had the genotype RRYY, which is homozygous dominant.

26. The Two-Factor Cross: F1 • The wrinkled green peas had the genotype rryy, which is homozygous recessive.

27. The Two-Factor Cross: F1 Which alleles are dominant for each trait? How do you know? All of the F1 offspring produced round yellow peas so we see that none of the traits from wrinkled green parent were expressed in the F1 offspring. • Round is dominant • Yellow is dominant

28. The Two-Factor Cross: F2 Would the two dominant alleles stay always stay together, or would they segregate independently so that any combination of traits was possible? • Mendel crossed F1 plants that were heterozygous dominant for round yellow peas.

29. The Two-Factor Cross: F2 He produced 556 peas. 315 of the F2 seeds were round and yellow 32 seeds were wrinkled and green—the two parental phenotypes. 209 seeds had combinations of phenotypes, and therefore combinations of alleles, that were not found in either parent. Principle of Independent Assortment:states that genes for different traits can segregate independently during the formation of gametes.

30. A Summary of Mendel’s Principles The inheritance of biological characteristics is determined by individual units called genes, which are passed from parents to offspring.

31. A Summary of Mendel’s Principles Where two or more alleles (forms) of the gene for a single trait exist, some forms of the gene may be dominant and others may be recessive.

32. A Summary of Mendel’s Principles In most sexually reproducing organisms, each adult has two copies of each gene—one from each parent. These genes segregate from each other when gametes are formed.

33. A Summary of Mendel’s Principles Alleles for different genes usually segregate independently of each other.

34. Genetic Probability What is the probability of that you will roll a 1 or 2 with dice? Each throw is an exclusive event. Add probabilities: 1/6 +1/6 = 2/6 or 1/3 1/6 1/6

35. Genetic Probability What is the probability of that you will roll two dice and both will come up 1 (snake eyes)? The events are happening at the same time. Multiply probabilities: 1/6 +1/6 = 1/36