2. HAPPY WEDNESDAY! – 1/8 Which of the following would be produced if a messenger RNA strand is coded from the DNA sequence CCCGGAATT? A CCCGGAAUU B GGGCCTTAA C AAATTCCGG D GGGCCUUAA

3. My Sophie

5. First Day of School

6. GENETICS & THE WORK OF MENDEL video

7. What is Genetics?  Genetics studies heredity.  Heredity is the passing of traits from parents to offspring.

8. Who is Father of Genetics?  Gregor Mendel – in mid-1800s, Austrian monk who was the first person to succeed in predicting how traits passed from parent to offspring  He used garden peas in his experiments.

9. Mendel’s Experiments  He controlled his experiments to ensure accurate results:  Self-Pollination – pea plant would pollinate itself  Cross-Pollination – one pea plant would pollinate another

10. Mendel’s Monohybrid Crosses  Mendel selected a white-flower plant and a purple-flower plant.  He crossed them to produce new plants.  Hybrid – offspring of parents that have different forms of a trait (ex. Tall and short height)  Monohybrid – “one trait”

11. Vocabulary 1. Gene – portion of DNA that codes for a trait or protein 2. Trait – inheritable characteristic 3. Allele – number of alternative forms of the same gene or same genetic locus (spot)

12. Vocabulary 4. Dominant allele/trait – trumps other alleles (hides them) and is written with an uppercase letter ex. Brown eyes are dominant = B 5. Recessive allele/trait – hidden if dominant allele is present and is written with a lowercase letter ex. Blue eyes are recessive = b

13. Vocabulary 6. Homozygous – both forms of the allele are the same; also known as purebred, true-breeding ex. Homozygous brown eyes = BB Homozygous blue eyes = bb 7. Heterozygous – forms of the allele are different; also known as hybrid ex. Heterozygous brown eyes = Bb

14. Pollen transferred from white flower to stigma of purple flower anthers removed all purple flowers result Mendel’s Work F1F1 P F2F2 self-pollinate  Parent generation (P):  White plant x Purple plant  First generation (F 1 ):  Produced all purple plants  F = filial  Second generation (F 2 ):  Self pollinate F 1 generation  Purple plant x purple plant produced 3 purple plants & 1 white plant.

15. F 2 generation 3:1 75% purple-flower peas 25% white-flower peas Looking closer at Mendel’s work P 100% F 1 generation (hybrids) 100% purple-flower peas X true-breeding purple-flower peas true-breeding white-flower peas self-pollinate

16. What did Mendel’s findings mean?  Traits come in alternative versions:  Purple vs. White flower color  Alleles - a number of alternative forms of the same gene or same genetic locus (spot) some difference in sequence of A, T, C, G purple-flower allele & white-flower allele are two DNA variations at flower-color locus different versions of gene at same location on homologous chromosomes

17. What did Mendel’s findings mean?  Some traits mask others:  purple & white flower colors are separate traits that do not blend purple x white ≠ light purple purple masked white  Dominant allele = purple flower color  Recessive allele = white flower color homologous chromosomes Purple Allele Dominant Trait White Allele Recessive Trait

18. Genotype vs. Phenotype  Difference between how an organism “looks” & its genetics: 1. Phenotype - description of organism’s trait Phenotype = Physical 2. Genotype - description of organism’s genetic makeup Genotype = Genetics Explain Mendel’s results using …dominant & recessive …phenotype & genotype F1F1 P X purplewhite all purple

19. Making Crosses  Can represent alleles as letters: **when choosing letters, pick letter where uppercase looks different then lowercase  flower color alleles  F or f  true-breeding purple-flower peas  FF  true-breeding white-flower peas  ff FF x ff F1F1 P X purplewhite all purple F F f f Ff

20. F 2 generation 3:1 75% purple-flower peas 25% white-flower peas ???? Looking closer at Mendel’s work P X true-breeding purple-flower peas true-breeding white-flower peas FF ff 100% F 1 generation (hybrids) 100% purple-flower peas Ff phenotype genotype self-pollinate What are genotypes of F 2 ?

21. Punnett Squares Ff x Ff Ff male / sperm F f female / eggs Genotype Phenotype FF Ff ff F 1 generation (hybrids) Aaaaah, phenotype & genotype can have different ratios!! FF = 25% Ff = 50% ff = 25% Purple = 75% White = 25% 1:2:1 ratio 3:1 ratio

22. HAPPY THURSDAY! – 1/9 A researcher designed an investigation to test what effect eating different types of food would have on blood insulin levels. She selected 10 male subjects who were all 25 years of age and in good health. The experiment took place over 3 days. At 8:00 a.m. on each day, the subjects ate a meal consisting of only 1 type of food. They had their blood insulin levels measured after consuming the meal. On day 1 they ate a high fat diet, on Day 2 they ate a high protein diet, and on Day 3 they ate a high sugar diet. What is the independent variable in this experiment? A the age of the subjects B the blood insulin level C the type of food consumed D the time of day the meal was consumed

23. HAPPY FRIDAY! – 1/10 In a certain type of mouse, black fur is dominant, and white fur is recessive. A scientist crosses a heterozygous black mouse with a white mouse. What percentage of the offspring will most likely have black fur? A 0% B 50% C 75% D 100%

24. Mendel’s Laws of Heredity  Law of Segregation:  Alleles for SAME trait separate into different gametes during meiosis.  Ex. Height  Law of Independent Assortment:  Alleles for DIFFERENT traits separate independently of each other during meiosis.  Ex. Blonde hair does not mean you have blue eyes. Traits inherited independently. Tt T t T t

25. Monohybrid Crosses Practice  Every genetics problem you work must include: 1. Key 2. Cross (Parent x Parent) 3. Punnett Square 4. Results (Genotype & Phenotype)

26. Monohybrid Crosses Practice 1. Black-colored (B) bear is dominant over brown-colored (b) bear. Cross a homozygous dominant bear with a heterozygous bear. Give phenotypic and genotypic results of F 1 generation. Key B = black b = brown Cross: BB x Bb B B b B BB Bb BB Genotype BB = 50% Bb = 50% 1:1 Ratio Phenotype Black = 100%

27. Monohybrid Crosses Practice 2. In human, dimples (D) is dominant over no dimples (d). Cross a hybrid woman with a man who does not have dimples. Give phenotypic and genotypic results of F 1 generation. What are the chances the couple will have a child with no dimples? Key D = dimples d = no dimples Cross: Dd x dd D d d d Dd dd Dd dd Genotype Dd = 50% dd = 50% 1:1 Ratio Phenotype Dimples = 50% No dimples = 50% 1:1 Ratio 50% chance of child with no dimples

28. 3. Curly hair (H) is dominant over straight hair (h). Cross a purebred curly haired woman with a true-breeding straight haired man. Give phenotypic and genotypic results of F 1 generation. Then, cross F 1 offspring to show phenotypic and genotypic results of F 2 generation. Key H = curly h = straight Cross: HH x hh H H h h Hh Genotype Hh = 100% Phenotype Curly = 100% H h h H HH hh Hh Genotype HH = 25% Hh = 50% hh = 25% 1:2:1 Ratio Phenotype Curly = 75% Straight = 25% 3:1 Ratio Cross: Hh x Hh Key H = curly h = straight F1F1F1F1 F2F2F2F2