1. I will compare mitosis and meiosis by completing a double bubble and web quest activity. Outcome

2. http://www.youtube.com/watch?v=65B V5dXXxzM http://www.youtube.com/watch?v=65B V5dXXxzM

3. Meiosis & Fertilization Sexual Reproduction - two individuals produce offspring that have genetic characteristics from both parents (unique – not clones!) Outcome (proposed): Distinguish between the products of mitosis and meiosis...

4. Meiosis The process that forms gametes (sex cells) These gametes (sex cells) are sperm and egg cells

5. Meiosis Chromosome number is reduced by one-half  2n  n  Diploid (2n) – 2 copies of each chromosome  Haploid (n) – 1 copy of each. End result – 4 haploid gametes

6. Meiosis 2 cell divisions

7. Chromosome Number OrganismSomatic (Body Cell) Gametes (sex cells) Human46 Kangaroo16 Pegasus50 23 8 100

8. Homologous Chromosomes Each cell has 2 copies of each chromosome Homologous chromosomes  Have the same genes in the same locations

9. Crossing-over Homologous chromosomes exchange parts Results in genetic variation  different combinations of genes 1 1 1 2 3 2 3

10. Fertilization Combination of gametes (sperm and egg) to form zygotes Zygote – diploid (2n) cell (two copies of each chromosome) formed by two haploid cells (1n + 1n = 2n)

11. Quick Quiz 1. Which of these does not occur during meiosis? (2007) A production of identical gametes B production of new gene combinations C crossing-over of homologous chromosomes D reduction of chromosome number by one-half 2. Sea stars are genetically different from each other and from their parents. These genetic differences are the result of (2006) A mitosis B cloning C sexual reproduction D asexual reproduction

12. Practice Questions 3. Horses have 64 chromosomes in each body cell. If a horse cell undergoes meiosis, how many chromosomes should be in each gamete? (2007) A 16 B 32 C 64 D 128 4. A sperm cell of a moth has 112 chromosomes. How many chromosomes are in the moth’s wing cells? (2005) A 66 B 112 C 224 D 448 64 Body cell 32 112 224

13. I will compare mitosis and meiosis by completing a double bubble and web quest activity. Outcome

14. Web Quest! Groups will follow the directions on their paper. Stay at your assigned lab station! When you are done, there is another activity to work on.

15. Computer Groups 2BEduardoIssac 2AJ-SwizzleBrian 3BLinhAnna L 3AVanessaMaya 4BChrisAiden 4ADesmondAlexa 5BJacobTars 5AAveryTeagan 6BB-RadKim 6AEliMeredith

16. Computer Groups Groups 2B MelvinPeter Tanner 2A NinaYanet 3B KerraGlendaLeanne 3A LaRonjaeSam 4B AkirahAlyannaNick 4A MalikJamar 5B KarenEmma G 5A ChrisColin 6B Emma PJessica F 6A Jessica SSophia 7B DreaSydney 7A JeniferDevon