2. Regents Biology Welcome to Semester 2 Topics  Genetics  Classification  Viruses/Bacteria  Very brief – plants and fungi  Animal Development  Animal Phyla  Human Body  Fresh Start for your Semester 2 Grade  Full effort, come in for help, get homework done, take notes, study for tests…set goals for a higher grade

3. Regents Biology Agendas Out  Plan for this week – write down your homework (use your agendas this semester – they help!)  Semester 1 Final Exam – if you want to go through the test, you may come in on your own time to check your answers (you will be given key to check with)

4. Regents Biology Zebra  Like our fingerprints – no two patterns are exactly the same  3 different species – each species does have a general pattern  Stripes distort distance at dawn and dusk – tricks predators  Social animals – graze together, groom each other  Some herds can have over a thousand members  Look-out for each other and protect the wounded of their group

5. Regents Biology Cucumber Genetics  In about 2 weeks we will be tasting cucumber cotyledons to determine whether they are the bitter or non-bitter variety – then we will collect data to determine the genes that code for bitter/non-bitter and their frequency  Today, you will be planting 1 seed in a pot of soil – don’t place seed too deep in soil  Water your plant  Label your name and hour on the pot/cup  WASH HANDS AFTER PLANTING

6. Regents Biology 2006-2007 Genetics *study of passing on of characteristics from parents to offspring Why do we look the way we do?

7. Regents Biology Inheritance of chromosomes  Meiosis = making sex cells (egg and sperm)  Egg + sperm  zygote egg sperm zygote fertilization mitosis & development meiosis

8. Regents Biology Inheritance of genes  On the chromosomes passed from Mom & Dad to offspring are genes  may be same information  may be different information eye color (blue or brown?) eye color (blue or brown?)

9. Regents Biology Effect of genes  Genes come in different versions  brown vs. blue eyes  brown vs. blonde hair  alleles

10. Regents Biology What did we show here?  Genes come in “versions”  brown vs. blue eye color  alleles  Alleles are inherited separately from each parent  brown & blue eye colors are separate & do not blend  either have brown or blue eyes, not a blend  Some alleles mask others  brown eye color masked blue

11. Regents Biology Genes affect what you look like X BB bb Bb Where did the blue eyes go??

12. Regents Biology Genes affect what you look like… X Bb bb Bb bb Why did the blue eyes stay??

13. Regents Biology Genes affect what you look like… X Bb BB or Bb bb Where did the blue eyes come from??

14. Regents Biology How does this work? eye color (brown?) hair color eye color (blue?)  Paired chromosomes have same kind of genes  but may be different alleles

15. Regents Biology Yunnan Snub-nosed Monkeys  Old world monkeys  Live in small part of China mountains, and a small colony is found in Tibet  Endangered  Specialist feeders – eat only lichens growing on the bark of pine trees  Named from short, stumpy nose  Live high up in mountain forests, up to 4700 meters up!  World’s highest living non-human primates  Live in groups of 20-60  Little is known about them – hard to study!  Not discovered until the 1990’s!

16. Regents Biology The Father of Genetics  Gregor Mendel – first person to predict how traits pass between generations  Studied pea plants  Self-pollination and cross-pollination  Studies 1 trait at a time - Monohybrid  Studies short vs. tall plants over several generations, then also studies other plant traits separately

17. Regents Biology Generations  P 1 = Parent  F 1 = First Filial (first set of offspring)  F 2 = Second Filial (second set of offspring)

18. Regents Biology Extending Mendelian genetics  Mendel worked with a simple system  peas are genetically simple  most traits are controlled by single gene  each gene has only 2 version  1 completely dominant (A)  1 recessive (a)  But its usually not that simple!

19. Regents Biology Traits are inherited as separate units 1 from Mom 1 from Dad  For each trait, an organism inherits 2 copies of a gene, 1 from each parent  a diploid organism inherits 1 set of chromosomes from each parent  diploid = 2 sets of chromosomes  Sex cells are haploid (1 set of chromosomes) homologous chromosomes

20. Regents Biology Laws of Genetics  Law of Segregation: - parent has two alleles for a gene - those alleles separate during meiosis - when male and female gametes (sperm and egg) pair, they randomly pair for different combinations

21. Regents Biology Laws of Genetics 2  Law of Independent Assortment: - genes for different traits are inherited independent of each other - ex. Height and color

22. Regents Biology Making gametes BB= brown eyes bb= blues eyes Bb= brown eyes BBbbBbBb  brown is dominant over blue  blue is recessive to brown Remember meiosis! B B b b B b

23. Regents Biology How do we say it? BB= brown eyes bb= blues eyes Bb= brown eyes 2 of the same Homozygous 2 different Heterozygous BB B B bb b b BbBb B b homozygous dominant homozygous recessive

24. Regents Biology Genetics vs. appearance  There can be a difference between how an organism looks & its genetics  appearance or trait = phenotype  brown eyes vs. blue eyes  genetic makeup = genotype  BB, Bb, bb 2 people can have the same appearance but have different genetics: BB vs Bb

25. Regents Biology Traits Inventory  Let’s check some of your traits and alleles you have  Traits Inventory Packet

26. Regents Biology Punnett squares (predict possible offspring) Bb x Bb male / sperm female / eggs X BB BbBbbb BbBb B b Bb

27. Regents Biology Genetics vs. appearance eye color (brown) eye color (brown) eye color (blue) eye color (brown) vs. BB B B Bb B b How were these brown eyes made?

28. Regents Biology 2005-2006 Woof! Woof! Any Questions?

29. Regents Biology 2005-2006 Dog Genes and Pea Pod WS  Let’s practice what we just went over!  Let’s do one Punnet Square Together – then take 8-10 minutes to complete the rest of the worksheet (both sides)

30. Regents Biology 2005-2006 Monohybrid Cross Worksheet  Due Thursday – you will have some time to work tomorrow if you finish lab early