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Meiosis

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Meiosis

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  1. Meiosis

  2. VOCAB THAT MUST BE KNOWN Ploidy: 1n, Haploid 2n, Diploid Chromatid Homologous chromsomes Tetrad Crossing Over

  3. Write Down… ALL THE Key Terms! nb - You have to actually define them to get credit at the end of the unit Ploidy Haploid (n) Diploid (2n) Tetrad Homologous Pair Crossing Over Somatic Cell Germ Cell Gamete Zygote Prophase I Metaphase I Anaphase I Telophase I Prophase II Metaphase II Anaphase II Telophase II Meiosis Sexual Reproduction Asexual Reproduction Chromatid Chromosome Genetic Recombination Fertilization Independent Assortment

  4. BellworkObj: Describe the process of meiosis • What are the 4 stages of mitosis? • Is interphase a part of mitosis? Explain. • What is the purpose of mitosis? • What is the difference between sexual reproduction and asexual reproduction? Give an example of a species for each. • Which type of reproduction would be more advantageous in nature and why? Explain in 1-2 complete sentences.

  5. On science fair boards:

  6. Each of the nucleus of your cells contains all this: Special cells in your body only have ½ this amount. Where? Why?

  7. Each somatic cell has: 2 copies of chromosome ONE -1 from mom, 1 from dad 2 copies of chromosome TWO -1 from mom, 1 from dad How to create a gamete: Meiosis Or ‘How to create an egg or a sperm’ Make a copy! Long red: mother/chromosome 1 Short red:Mother/chromosome 2 Long blue: father/chromosome 1 Short blue: father/chromosome 2 Each gamete has: 1 MIXED copy of chromosome ONE 1 MIXED copy of chromosome TWO

  8. the diploid somatic cells of an individual contain one copy of the chromosome set from the sperm and one copy of the chromosome set from the egg; that is, the cells of the offspring have genes expressing characteristics of both the father and the mother.

  9. A gamete (from Ancient Greekγαμετήgamete "wife"[1]) is a cell that fuses with another cell during fertilization (conception) in organisms that reproduce sexually. • A gamete's chromosomes are not exact duplicates of either of the sets of chromosomes carried in the dfs chromosomes.

  10. GAMETES 23=N HAPLOID MEIOSIS SOMATIC 46=2N DIPLOID MITOSIS CROSSING OVER

  11. Each somatic cell has: 2 copies of chromosome ONE -1 from mom, 1 from dad 2 copies of chromosome TWO -1 from mom, 1 from dad How to create a gamete: Meiosis Or ‘How to create an egg or a sperm’ Make a copy! Long red: mother/chromosome 1 Short red:Mother/chromosome 2 Long blue: father/chromosome 1 Short blue: father/chromosome 2 Each gamete has: 1 MIXED copy of chromosome ONE 1 MIXED copy of chromosome TWO

  12. Mitosis vs Meiosis Mitosis Body cell division (cloning) Mitosis makes “my toes-es” MeiosisMaking sex cells (halving) Meiosis makes “my OH…baby!”

  13. Meiosis Meiosis • _________________ is the process that ___________________ cells undergo when a single cell ____________ to make ___ unique ________________ daughter cells Somatic (diploid) divides 4 haploid

  14. Meiosis Explain to your partner • How many original cells were there? • How many cells did it divide into? • Were all these new cells the same? • What do we call the new cells?

  15. How do Organisms Reproduce? Organisms either reproduce sexually or asexually. Sexually reproducing • Meiosis only occurs in ____________________species

  16. Asexual reproduction Asexual reproduction involves formation of a new individual from cells of the parent, without meiosis, gamete formation, or fertilization.

  17. Question???? Asexual reproduction involves formation of a new individual from cells of the parent, without meiosis, gamete formation, or fertilization. • So, why, if an animal is reproducing asexually, does meiosis NOT occur?

  18. Sexual Reproduction chromosomes In sexual reproduction the ______________________ of one parent are _______________ with that of the other parent to produce a __________________ _________________ offspring. combined genetically unique

  19. Meiosis Video • http://www.youtube.com/watch?v=kVMb4Js99tA

  20. Fill in the diagram as we go Meiosis II Meiosis I

  21. Prophase I __________ form and ___________ _______ occurs! Tetrads crossing over

  22. Tetrads & Crossing Over Tetrads- ______ association of sister chromatids of ____________ _____________ (4) close Crossing Over: Homologous chromosomes _________ small pieces, resulting in ____ chromosomes! exchange homologous chromosomes NEW

  23. Tet Cr-O 1. What are ‘sister chromatids’ • Why did we keep them together in mitosis? 2. What are ‘homologous’ chromosomes? -Genes for eye color and height are both on chromosome 11 for humans.

  24. Metaphase I

  25. Anaphase I _____________ _____________ occurs creating _____combinations! Independent Assortment new

  26. Independent Assortment Chromosomes from the _____ & _____ _________ move to one side or the other mom dad randomly

  27. Telophase I

  28. (Cytokinesis)

  29. Each somatic cell has: 2 copies of chromosome ONE -1 from mom, 1 from dad 2 copies of chromosome TWO -1 from mom, 1 from dad How to create a gamete: Meiosis Or ‘How to create an egg or a sperm’ Make a copy! Long red: mother/chromosome 1 Short red:Mother/chromosome 2 Long blue: father/chromosome 1 Short blue: father/chromosome 2 Each gamete has: 1 MIXED copy of chromosome ONE 1 MIXED copy of chromosome TWO

  30. Prophase II

  31. Metaphase II

  32. Anaphase II

  33. Telophase II

  34. (Cytokinesis)

  35. Summary of ways Meiosis is different from Mitosis • Involves _________________________________________ 2 consecutive cell divisions

  36. Summary of ways Meiosis is different from Mitosis • Ends with ___ cells that are all _______________ (sex cells: _______& ____) 4 haploid sperm egg

  37. Summary of ways Meiosis is different from Mitosis • Makes _____ _________________ combinations through ___________ ______ and _____________ __________ genetic NEW crossing over independent assortment

  38. Meiosis Card Sort Order the 11 cards to show the progress from a single cell in interphase and progressing to 4 haploid sex cells

  39. Funny Meiosis Video • http://www.youtube.com/watch?v=iCL6d0OwKt8

  40. Slate Quiz! • Look at the pictures on the following slides & name the stage of meiosis!

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