Bio 9B: Tuesday, 3.22.11 Title: Introduction to Genetic Inheritance and Variation

1. Bio 9B: Tuesday, 3.22.11Title: Introduction to Genetic Inheritance and Variation Double Block • Homework: • Complete the Making Babies Analysis Questions • Silent Do Now: (in notebook w/ title and date) • What is the difference between a gene and an allele? (Check your notes from last week if you don’t remember) • How do you think a dominant allele is different from a recessive allele? What do you think dominant and recessive mean? • Predict what you think genotype and phenotype mean (these are new words we will learn today) • Hand in Modeling Meiosis packet and Karyotyping Part II packet if you didn’t hand them in yesterday • Today’s Objectives: • Use genetics vocabulary to describe genes and alleles • Differentiate between genotypes and phenotype • Experiment with probability to see the diversity of offspring that can be made through sexual reproduction

2. Agenda Introduction to new Genetics Terms (10 min) Makin’ Babies Activity Explanation (5 minutes) Activity (25 minutes) Post picture of the Baby on the front board Introduction to Punnett Squares/ Monohybrid Crosses (15 Min) Making Babies Probability w/ clickers (15 min) Making Babies Analysis Questions (20 min)

3. Mendelian genetics:the study of genetic inheritance patterns Biology 9: Moretti / Dickson

4. Genetics Overview • Genetics is the study of gene inheritance and variation • Genetics answers big questions like: • How are traits inherited? • Why do offspring look similar to their parents but not exactly like their parents? • How do we have so many different types of organisms and so much genetic variation? • Objectives for Class: • Experiment with probability to see the diversity of offspring that can be made through sexual reproduction

5. Genetics Vocabulary: Gene: A section of DNA that encodes a particular protein (ex: hair protein) Alleles: Different versions of a gene (ex: black hair vs. blond hair) Everyone has two alleles for each gene – one from each parent!

6. Mendelian Genetics and Probability • New Vocabulary: • Dominant and Recessive • Dominant: • The allele that is always expressed as a trait if it is present (regardless of other alleles) • Recessive: • The allele that is only expressed as a trait if the dominant allele is not present Evidence: True-breeding yellow x True-breeding green (YY)(yy) All yellow offspring (Yy) • Objectives for Class: • Experiment with probability to see the diversity of offspring that can be made through sexual reproduction

7. Mendelian Genetics and Probability • New Vocabulary: • Genotypes and Phenotypes • Genotypes: • The genetic make-up of an organism • The combination of alleles • Phenotypes: • The expressed physical characteristics • The “Trait” “Phenotypes are the sum of Genotypes + Environment” • Objectives for Class: • Experiment with probability to see the diversity of offspring that can be made through sexual reproduction

8. “Makin’ Babies”:Mendelian Genetics and Probability Step 1: Genotype Data Table” Determine the Traits of your baby by flipping the coin a total of two times for each trait (once for each allele). Heads = Dominant and X Tails = Recessive and Y Example: Face shape = R, so heads=R and tails = r Write the combination of the alleles in the box next to the trait. This is the Genotype for each trait Step 2:Phenotype chart Determine the Phenotype based on the Genotype from page 1 Example: if you flipped two RR for face shape, the phenotype would be Round Step 3: Draw your baby by using the traits from the Phenotype chart

9. More Genetics Vocabulary • Homozygous and Heterozygous • Homozygous: Two of the same allele for a particular trait are present • Ex: RR (homozygous dominant) = Round Face • Ex: rr (homozygous recessive)= Square Face • Heterozygous: Two different alleles for a particular trait are present • Ex: Rr = Round Face • Objectives for Class: • Experiment with probability to see the diversity of offspring that can be made through sexual reproduction

10. Making Babies – Predicting Probabilities In the activity, the mother and father were both heterozygous for each trait Mother was RrFather was Rr half of the sperm got each allele R r ½ of Mom’s eggs got the R allele ½ of Mom’s eggs got the r allele Rr R RR Rr rr r

11. Making Babies – Predicting Probabilities This Punnett Square is used to PREDICT PROBABILITIES, NOT to tell you the actual numbers you will get! Probability of Round Face (RR or Rr) = ¾ or 75% Probability of Square Face (rr) = ¼ or 25% R r Rr R RR Rr rr r

12. Now let’s make predictions for the sex of the baby (boy or girl?) XX • Mother’s genotype: • Father’s genotype: • Make a Punnett Square and fill it in XY X Y Chances of girl (XX) = ½ or 50% Chances of boy (XY) = ½ or 50% XY X XX XX XY X

13. Your Clicker Number:Write it on the FRONT of your notebook

14. Now let’s see if the class’s babies match our predicted probabilities! • Take out the Making Babies packet and turn to the very back page • We will use clickers to collect data for Analysis Question #5 • Calculate Expected Ratios for the following traits

15. Phenotype Class Results:What is the face shape of your baby? • Round (dominant) • Square (recessive) • Objectives for Class: • Experiment with probability to see the diversity of offspring that can be made through sexual reproduction 21 of 25

16. Phenotype Class Results:Does your baby have a cleft chin? 25 • No, it’s absent (dominant) • Yes, it’s present (recessive) 21 • Objectives for Class: • Experiment with probability to see the diversity of offspring that can be made through sexual reproduction

17. Phenotype Class Results:Does your baby have a widow’s peak? • Yes, it’s present (dominant) • No, it’s absent (recessive) 22 of 25 • Objectives for Class: • Experiment with probability to see the diversity of offspring that can be made through sexual reproduction

18. Phenotype Class Results:What kind of earlobes does your baby have? • Unattached (dominant) • Attached (recessive) 22 of 25 • Objectives for Class: • Experiment with probability to see the diversity of offspring that can be made through sexual reproduction

19. Phenotype Class Results:What is the gender of your baby? • Girl (XX) • Boy (XY) 25 22 of 25 • Objectives for Class: • Experiment with probability to see the diversity of offspring that can be made through sexual reproduction 0

20. Now let’s see if the class’s babies match our predicted probabilities! • Take out the Making Babies packet and turn to the very back page • We will use clickers to collect data for Analysis Question #5

21. Making Babies – Analysis Questions • Answer all questions on a separate piece of paper • This is HW due tomorrow!

22. Bio 9B: Wednesday, 3.23.11Title: No Class – Half Day • Homework: • Do Now: • Today’s Objectives:

23. Bio 9B: Thursday, 3.24.11Title: Genetic Inheritance & Variation - Mendel’s Principle of Segregation • Homework: • Complete the remaining questions from the Monohybrid Crosses Worksheet • Also, read pgs 267-273 and complete the “Reviewing Mendel’s 4 Principles of Genetic Inheritance” guide. Additionally, review key vocabulary that we have gone over in class and be sure to have the terms explained in your notebook. • Do Now: • Get a clicker and answer the questions on the following slides • You will need the Making Babies Analysis Questions • Today’s Objectives: • Use Mendel’s Principle of Segregation to explain: How can children show traits that their parents don’t have? • Use Punnett Squares to solve monohybrid crosses

24. Do Now: Which of the following terms applies to traits, such as eye color, that are controlled by more than one gene? 22 • Codominant • Polygenic • Recessive • Dominant 20

25. Vocabulary Review Pass Making Babies to the left!

26. DO NOW: Does this picture show GENOTYPES or PHENOTYPES? “Click” your answer… • Genotypes • Phenotypes 21 of 23 • Objectives for Class: • Differentiate between genotypes and phenotypes :29

27. Vocabulary Review • Genotype: • genetic make-up/combination of alleles (Ex: AA, Aa, or aa) • Phenotype: • The traits that an organism has (Ex: purple flowers or white flowers) • Trait: • a specific characteristic that varies between individuals (Ex: flower color) • Objectives for Class: • Differentiate between genotypes and phenotypes

28. Vocabulary Review • Fill in the blanks… What is the phenotype? What is the phenotype? What is the genotype? • Which allele is dominant? Recessive? How do you know? • Purple (A) = Dominant • White (a) = Recessive • Objectives for Class: • Differentiate between genotypes and phenotypes

29. New(ish) Vocabulary • Fertilization: • the joining of two gametes in sexual reproduction • Zygote: • a fertilized egg cell that will grow and develop into an offspring

30. A human zygote, like most other human cells, contains 46 chromosomes. How many chromosomes does the a zygote receive from the mother? 23 • 12 • 23 • 46 • 92 19

31. In the diagram below, which process is fertilization? • Process A • Process B 20 of 23

32. Monohybrid Punnett Square Practice

33. In guinea pigs, rough coat (R) is dominant over smooth coat (r). A heterozygous guinea pig is mated with another heterozygous pig.What percentage of the next generation will have smooth coat? 23 • 100% • 50% • 25% • 75% 3

34. Introduction to Mendelian Genetics

35. Some background on Mendel and what he did to advance genetics You Don’t need to write this down: • GregorMendel studied genetics by doing experiments with pea plants. • He started with true-breeding plants, which he knew were homozygous for their traits. • Objectives for Class: • Use Mendel’s Principle of Segregation to explain: How can children show traits that their parents don’t have? • Use Punnett Squares to solve monohybrid crosses

36. Some background on Mendel and what he did to advance genetics You don’t need to write this down: • GregorMendel studied genetics by doing experiments with pea plants. • He started with true-breeding plants, which he knew were homozygous for their traits. • When he cross-bred these plants, he found that one phenotype was dominant over the other. • But when he cross-bred the offspring, the recessive phenotype reappeared! • How can we explain this?? • Objectives for Class: • Use Mendel’s Principle of Segregation to explain: How can children show traits that their parents don’t have? • Use Punnett Squares to solve monohybrid crosses

37. CW/ HW Monohybrid Crosses • Complete Question 1 (you will need to reference a book • In sheep, the allele for black wool (a) is recessive and the allele for white wool (A) is dominant. Imagine that two white sheep that are heterozygous mate with each other to produce lambs. • Trace the alleles for each parent through diagrams of Meiosis. Show the positions of the alleles on the chromosomes at: Metaphase I, Metaphase II, and at the end of meiosis. (In other words, draw the chromosomes & the alleles!)

38. Review Principle of Segregation

39. Mendel’s Discoveries: Principle of Segregation • Alleles segregate (separate) during meiosis so each gamete gets one allele A A a Two choices for gametes: A or a a A A a a

40. Volunteer to Draw Punnett Square? • 1c • Draw a Punnett Square showing the possible results of 2 heterozygous white sheep mating

41. Principle of Segregation (continued…) • This explains why the recessivetrait reappears in the F2generation… • In ¼ of the offspring. Source of Gametes

42. Review: Principle of Segregation and Meiosis Original Diploid Cells AA Aa Aa Aa Aa A a A a aa Segregation Possible Haploid Gametes Fertilization Possible Diploid Zygotes

43. CW/ HW Monohybrid Crosses • Complete Questions 2 – 4

44. Bio 9B: Monday, 3.28.11Title: Dihybrid Crosses and Mendel’s Principle of Independent Assortment • Homework: • Complete the remaining questions from the Dihybrid Crosses Worksheet • Do Now: • What are Mendel’s 4 Principles of Genetic Inheritance? • Today’s Objectives: • Use Punnett Squares to solve dihybrid crosses • Use Mendel’s Principle of Independent Assortment to explain how genetic variation is created in individuals.

45. AGENDA Pass Back Work Review HW Review Mendel’s 4 Principles of Inheritance Principle of Independent Assortment and DiHybrid Crosses

46. Question 2 (d): What is the probability of purple flowers? 26 • 25% • 50% • 75% • 0% 19

47. Question 3 (C): If Ben and Jaelene has a child, what is the probability s(he) will have attached earlobes? 26 • 25% • 50% • 75% • 0% 19

48. Question 4 (b): A cross between a cow and a bull that both have red and white spots. What are the probabilities of a red calf? 26 • 25% • 50% • 75% • 0% 18

49. Review Mendel’s Principles of Inheritance • Genes in Pairs: • Traits are controlled by genes that occur with two different forms (alleles) • Principle of Dominance: • Some alleles are dominant and others are recessive • Principle of Segregation: • The two alleles for a gene segregate(separate) during meiosis so each gamete gets one allele • Principle of Independent Assortment (new): • Alleles for different genes separate independently during meiosis.

50. What is one difference between these two cells? Cell 2 A • Which chromosome is homologousto this one? • If we looked at human cells, how many pairs of homologous chromosomes would they contain? • Answer: 23 pairs (22 pairs plus the sex chromosomes) A Cell 1 b b A A a a B B a a