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Cell Division

Cell Division

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Cell Division

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  1. Cell Division By: Amber Tharpe

  2. Activation • Humans make 2 trillion new cells per day

  3. Cell Cycle • 2 main parts • Interphase- Cell is normal • Mitosis- Cell is dividing • Cytokinesis- occurs at the end of mitosis

  4. Mitosis • Divides DNA into 2 nuclei • Makes 2 daughter cells with a diploid number • Used for growth and repair • Also used in some asexual reproduction

  5. 4 stages (P-M-A-T) Prophase Metaphase Anaphase Telophase

  6. Stages of Mitosis (P-M-A-T) Prophase Early Prophase Interphase http://micro.magnet.fsu.edu/micro/gallery/mitosis/mitosis.html Metaphase Early Anaphase Telophase Anaphase

  7. Prophase DNA condenses Nuclear envelope dissolves Spindle fibers start to form

  8. Prophase(in animal cell and onion cell)

  9. Metaphase Chromosomes align in the middle of the cell (equator) Spindle fibers attach to the chromosomes to move them

  10. Metaphase

  11. Anaphase Chromosomes separate to opposite poles Spindle fibers split chromosomes in half

  12. Anaphase

  13. Telophase • 2 nuclear envelopes form around the separated DNA • Spindle fibers dissolve • In animal cells • Cell membrane pinches in • In plant cells • Cell plate forms which later becomes 2 cell walls

  14. Telophase

  15. Cytokinesis Cytoplasm and organelles divide 2 cells form

  16. http://www.classzone.com/cz/books/bio_07/get_chapter_group.htm?cin=2&rg=animated_biology&at=animated_biology&var=animated_biologyhttp://www.classzone.com/cz/books/bio_07/get_chapter_group.htm?cin=2&rg=animated_biology&at=animated_biology&var=animated_biology

  17. Animation of Stages of Mitosis http://biology.about.com/library/blmitosisanim.htm

  18. Asexual Reproduction 1 parent Offspring is identical to parent Less genetic diversity

  19. Binary Fission Asexual reproduction for bacteria DNA is copied in 1 cell The cell divides into 2 cells with the same DNA

  20. Binary Fission

  21. http://www.classzone.com/cz/books/bio_07/get_chapter_group.htm?cin=2&rg=animated_biology&at=animated_biology&var=animated_biologyhttp://www.classzone.com/cz/books/bio_07/get_chapter_group.htm?cin=2&rg=animated_biology&at=animated_biology&var=animated_biology

  22. Chromosome Long thread of DNA containing many genes X- shaped

  23. Somatic cells Body cells All cells not involved in reproduction Diploid cells (2N) Contains 2 copies of each chromosome In humans 46 chromosomes Made by mitosis

  24. Gametes Sex cells Egg (female) or sperm (male) Haploid cells (1N) Contains 1 copy of each chromosome In humans 23 chromosomes Made by meiosis Used in sexual reproduction

  25. Sex Chromosomes Chromosome pair 23 for gender Either X or Y XX is female XY is male

  26. Sexual Reproduction Offspring are a mixture of both parents Occurs by meiosis then fertilization Meiosis Formation of gametes Makes haploid cells from diploid cells Fertilization The actual fusion of the 2 gametes First cell is called a zygote

  27. Meiosis Process of making gametes for sexual reproduction Events that occur during meiosis allows for greater genetic diversity

  28. Meiosis Meiosis I Makes 2 unique diploid cells Prophase I – Telophase I Interphase without duplicating DNA Meiosis II Makes 4 unique haploid cells Prophase II – Telophase II

  29. Crossing Over Occurs in Prophase I Homologous chromosomes line up and sections of the chromosomes overlap and become incorporated into the other Allows for genetic diversity

  30. Independent Assortment Occurs in Metaphase I Independent Assortment Allows for genetic variation When homologous chromosomes line up in the middle, some chromosomes from the mother and father line up on either side

  31. Telophase II Produces 4 haploid cells with unique combinations of chromosomes Females produce 1 ovum (egg) and 3 polar bodies Males produce 4 sperm cells