Meiosis presentation for PFS 2014


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Life sciences education on Meiosis done by a third year education student majoring in life science

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Meiosis presentation for PFS 2014

  1. 1. JL Broadhurst 201242029
  2. 2. Cell division for  sex-cells. Sex Cells:  Are also called Gametes. You know them as SPERM and EGG cells
  3. 3.  2 divisions: Meiosis I and Meiosis  Starting with ONE (diploid) cell, II ending with FOUR (haploid) cells.
  4. 4. Interphase: Chromosomes duplicate and build up energy for meiosis
  5. 5. Meiosis I  Prophase I  Metaphase I  Anaphase I  Telophase I Meiosis II  Prophase II  Metaphase II  Anaphase II  Telophase II
  6. 6.  Prophase I- chromosome becomes visible and the nuclear membrane disappears; homologous chromosome appears and share fragments called crossing over
  7. 7. Meiosis I Metaphase I - complete disappearance of nuclear membrane and appearance of spindle fiber; centromeres attached to the spindle fiber and lies on the metaphase plate.
  8. 8. Meiosis I Anaphase I homologous chromosome separates from each other but centromere do not divide; chromosome continues to consists of two chromatids
  9. 9. Meiosis I Telophase I chromosomes are still doubled; nuclear membrane is formed and disappearance of spindle fiber
  10. 10. cells have one chromosome
  11. 11. Meiosis II Metaphase II chromosomes align at the metaphase plate; centromeres divide thus separating the chromatids
  12. 12. Meiosis II Anaphase II each new daughter cell move towards opposite poles
  13. 13. Meiosis II Telophase II spindle disappears; nuclear membrane is formed; nuclei are formed and cytokinesis happens
  14. 14.  Mitosis makes cells for growth, development, repair, and is a form of asexual reproduction  Meiosis makes gametes for sexual reproduction
  15. 15.  Mitosis produces two cells identical to the parent cell (diploid called daughter cells)  Meiosis produces four cells with half the number of chromosomes as the parent (haploid)
  16. 16.  In the first cell division, CHROMOSOME PAIRS (HOMOLOGOUS CHROMOSOMES) are separated.  In the second cell division, SISTER CHROMATIDS are pulled apart.
  17. 17.  In meiosis, “crossing over” occurs during prophase I.  Chromosomes form tetrads  Homologous chromosomes “swap” parts of their DNA  leads to recombination, or genetic variation
  18. 18. Meiosis lesson by imkaelah on Jul 24, 2013  Powerpoint meiosis by Magdalena Ravagnan, Veterinaria, Biology teacher from Argentina on Jun 16,2013  Meiosis in depth by Jeff Kalember on Jan 30, 2014  Meiosis by mjurkiewicz on Dec 14, 2013  Biology unit 4 cell division meiosis notes by rozeka01 on Dec 12, 2013 