1. AP Biology Discussion Notes Wednesday 3/25/2015

2. Goals for the day Be able to predict the outcomes of crosses with intermediate inheritance, co-dominance, or multiple alleles Be able to define and perform dihybrid crosses and use multiple strategies to predict the outcomes Be able to use probabilities to simplify & complete complex problems.

3. Question of the day 3/25 Fill out the 3 questions at the top of your note sheet -

4. Intermediate Inheritance & Co- Dominance Answer the 3 questions at the top of your page.

5. Intermediate Inheritance & Co- Dominance 1. Based on the problems you have done previously, predict the PHENOTYPE(s) of the offspring from a cross between a Red flower and a white flower where red is dominant to white.

6. Intermediate Inheritance & Co- Dominance 2. How many phenotypes were possible in the problems we have done so far (look at the legend or the phenotypic ratio)?

7. Intermediate Inheritance or Incomplete Dominance 3. What does intermediate mean? What does incomplete mean?

8. Intermediate Inheritance Intermediate Inheritance/ Incomplete Dominance - is when two alleles BLEND together.

9. Example: When you cross a Red (F R F R ) flower with a White flower (F W F W ) you get all pink flowers (F R F W ) in the offspring. (Red x White = 100% Pink) Legend ParentsCross itGenotypic Ratio Phenotypic Ratio

10. Intermediate Inheritance or Incomplete Dominance Note in the cross that the Genotype & Phenotype ratios are now the same!

11. Co-Dominance What does Dominance mean? What does “CO” mean? (As in cooperate or Coauthors)

12. Co-Dominance = Dominant together Co-Dominance means: BOTH alleles are represented that is they both SHOW UP! (They are dominant together)

13. Intermediate inheritance & Co- Dominance * The difference between Intermediate Inheritance & Co- dominance is in the PHENOTYPE. In Intermediate Inheritance (aka Incomplete Dominance) the alleles _________ together. In Codominance both alleles _____ _______, are EXPERESSED (Both traits are seen in the phenotype)

14. Cross a homozygous black dog with a homozygous white dog Legend ParentsCross itGenotypic Ratio Phenotypic Ratio

15. Intermediate inheritance & Co- Dominance Questions?

16. Multiple alleles Some traits may be expressed by more than two possible alleles. This is multiple allele expression. One very important trait expressed through multiple alleles is human blood type.

17. Multiple alleles There are four possible types of human blood: –A, B, AB, and O These are expressed by immunoglobulin proteins, so the three possible alleles are written in this way: I A & I B are both CO-DOMINANT (they both _______ ___) and i is recessive to them.

18. Multiple alleles Multiple alleles – Traits are controlled by more than 2 possible alleles.

19. Multiple alleles Even with multiple alleles each individual still only gets _______ alleles for each trait! One allele from _______ and one allele from ______

20. Multiple alleles Blood types in humans are a good example of a multiple allele trait. - They are also an example of CO-Dominance – dominant together – Both alleles/traits _________ _____. Blood Type (________type) Alleles (_______type) I A I A or I A i I B I B or I B i IAIBIAIB ii

21. Multiple alleles Very Important in Blood Transfusions!

22. Multiple alleles Very Important in Blood Transfusions!

23. Multiple alleles 1. One parent is homozygous type A and the other is heterozygous type A Leg end ParentsCross itGenotypic Ratio Phenotypic Ratio

24. Mendel’s Law of Segregation Each individual has a pair of factors (alleles) for each trait The alleles segregate (separate) during gamete (sperm & egg) formation Each gamete contains only one factor (allele) for each trait Fertilization gives the offspring two factors (alleles) for each trait

26. Dihybrid Crosses Up until now we have been looking at Monohybrid crosses. Mono means _______. This is to say that we have been looking at one ________, or characteristic, at a time. Often times we want to look at two traits at once. If we are looking at the outcomes of two traits in one cross we will call it a __________ ___________. Di = _______ Mono = _________

27. Dihybrid Crosses Often times we want to look at two traits at once. If we are looking at the outcomes of two traits in one cross we will call it a Dihybrid Cross Di = _______ Mono = ______

28. Dihybrid Crosses Dihybrid cross – two trait cross In monohybrid crosses each parent was represented with ___ alleles and there were ____ possible allele combinations. (Ex. A parent could be AA, Aa, or aa)

29. Dihybrid Crosses Dihybrid cross – two trait cross In Dihybrid crosses there are ___ alleles/parent and ____ possible Allele Combinations.

30. Mendel tested Two-Trait Inheritance Dihybrid cross Mendel used true- breeding (__________/____________) plants differing in two traits – Observed phenotypes among F 2 plants – Formulated Law of Independent Assortment

31. Mendel’s Law of Independent Assortment The Alleles for one trait segregate (separate) independently of the alleles for other traits All possible combinations of alleles can occur in the gametes(________/_______) *These are ____________ cells ( __ n) and made through the process of ____________

32. Meiosis Review Let’s refresh our Memory! Organism Cell type & chromosome # Haploid #Diploid # Mountain GoatHorn cell = 50 Leopard SealTongue cell = 10 Amaryllis BulbEgg cell = 15 Emperor PenguinSperm cell = 20 Bald EagleHeart cell = 100

33. Meiosis Review Let’s refresh our Memory! Organism Cell type & chromosome # Haploid #Diploid # Mountain GoatHorn cell = 50 25 50 Leopard SealTongue cell = 10 Amaryllis BulbEgg cell = 15 Emperor PenguinSperm cell = 20 Bald EagleHeart cell = 100

34. Meiosis Review Let’s refresh our Memory! Organism Cell type & chromosome # Haploid #Diploid # Mountain GoatHorn cell = 50 25 50 Leopard SealTongue cell = 10 5 10 Amaryllis BulbEgg cell = 15 Emperor PenguinSperm cell = 20 Bald EagleHeart cell = 100

35. Meiosis Review Let’s refresh our Memory! Organism Cell type & chromosome # Haploid #Diploid # Mountain GoatHorn cell = 50 25 50 Leopard SealTongue cell = 10 5 10 Amaryllis BulbEgg cell = 15 15 30 Emperor PenguinSperm cell = 20 Bald EagleHeart cell = 100

36. Meiosis Review Let’s refresh our Memory! Organism Cell type & chromosome # Haploid #Diploid # Mountain GoatHorn cell = 50 25 50 Leopard SealTongue cell = 10 5 10 Amaryllis BulbEgg cell = 15 15 30 Emperor PenguinSperm cell = 20 20 40 Bald EagleHeart cell = 100

37. Meiosis Review Let’s refresh our Memory! Organism Cell type & chromosome # Haploid #Diploid # Mountain GoatHorn cell = 50 25 50 Leopard SealTongue cell = 10 5 10 Amaryllis BulbEgg cell = 15 15 30 Emperor PenguinSperm cell = 20 20 40 Bald EagleHeart cell = 100 50 100

39. Mendel’s Law of Independent Assortment Round is _______________ to wrinkled. Yellow is ________________ to green. In honor of Mendel we will do an example of a dihybrid cross with pea plants. R – Round r – wrinkled Y – Yellow y - green

40. Dihybrid Cross F 1 gen. all (100%) RrYy Parental Generation (P 1 ): RRYY x rryy Possible Gamete(s) from RRYY: Possible Gamete(s) from rryy:

41. Dihybrid Cross – F.O.I.L F 1 generation: RrYy F – first O – Outside I – Inside L - Last Possible Gametes from RrYy: ______, ______, ______, _______ RrYy

42. RYRyrYry RY Ry rY ry R=Roundr =wrinkled Y= Yellowg= green RrYy

43. RYRyrYry RY RRYY RRYY RRYy RrYY RrYyRrYy Ry RRYy RRYy RRyy RRyy RrYy Rryy rY RrYY RrYY RrYy rrYY rrYY rrYy ry RrYy RrYy Rryy Rryy rrYy rrYy rryyrryy R=Roundr =wrinkled Y= Yellowg= green RrYy

44. Phenotype (Phenotypic Ratio) Round & Yellow: ___/16 Round & ________: ___/16 _________ & Yellow: ___/16 __________ & __________ : ___/16

45. Phenotype (Phenotypic Ratio) Round & Yellow: ___/16 Round & ________: ___/16 _________ & Yellow: ___/16 __________ & __________ : ___/16

46. RYRyrYry RY RRYY RRYY RRYy RrYY RrYyRrYy Ry RRYy RRYy RRyy RRyy RrYy Rryy rY RrYY RrYY RrYy rrYY rrYY rrYy ry RrYy RrYy Rryy Rryy rrYy rrYy rryyrryy R=Roundr =wrinkled Y= Yellowg= green RrYy

47. Dihybrid Crosses Phenotypic Ratio: ___: ___: ___: ___ - This will always be the phenotypic ratio for a Heterozygote cross in normal patterns of inheritance. *This will also be a test question! Typically for Dihybrid Crosses we will only ask you to find the Phenotypic Ratio, and not the Genotypic Ratios

48. Dihybrid Crosses REVIEW There are now __ possible allele combinations that could be passed on in the gametes of these parents. Remember that Crossing over, which happens during Prophase 1 of Meiosis, is a source of _______________. *This Variation is in part why we might be able to have __ different allele combinations.

49. Dihybrid Crosses REVIEW *This Variation is in part why we might be able to have 4 different allele combinations. If I had a heterozygote AaBb I might have AB on one chromosome and ab on another. The possible gametes then would only be AB and ab. The ONLY WAY to get the other possible gametes ___ ___ & ___ ___ are through crossing over which allows the gametes to inherit the alleles in a different way to have (VARIATION)!!!

50. Wednesday PM I will be unavailable – talk to me if you plan to work on corrections after school.

51. Species of the Day 3/25 Common Grackle -Quiscalus quiscula

52. Species of the Day 3/25 Common Grackle -Quiscalus quiscula

53. Species of the Day 3/25 Common Grackle -Quiscalus quiscula European Starling -Sternus vulgaris