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Warm Up

Discover the fascinating journey of cell reproduction and its vital role in growth, repair, and reproduction. Starting as a single cell, you are now composed of approximately 75 trillion cells, constantly renewed to maintain health. This overview covers key processes such as binary fission in prokaryotes and the complex phases of mitosis in eukaryotes. Learn about the significance of chromosomes, the cell cycle stages, and how internal and external signals regulate cell growth. Explore the critical implications of uncontrolled cell growth and cancer.

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Warm Up

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Presentation Transcript

  1. Warm Up You began life as a single cell, and now you are approximately 75 trillion cells! How did that happen?

  2. Cell Reproduction Chapter 6 – Bio 1-2 Book (Blue)

  3. All Cells come from Cells • The division of cells into more cells enables living things to repair damage, to grow and to produce offspring.

  4. Repair & Growth • You are made of 75-100 Trillion Cells! • Your cells continually need to be replaced, they wear out. • Digestive Tract – few days • Immune system cells – 6 weeks • Pancreatic Cells – 1 year

  5. The Cell Cycle: Prokaryotes – no nucleus • Binary Fission: • Cell division in a single celled organism produces two genetically identical organisms. • Asexual Reproduction • Circular Chromosome- See video

  6. What part of the cell is our focus? The nucleus!

  7. The Cell Cycle: Eukaryotes (with a nucleus) • Chromatin: • DNA wrapped around protein • Chromosome: • Chromatin made compact for cell division. • Sister Chromatids: • Two identical chromosomes joined together. • Centromere: • The region where two chromatids join. Chromosome

  8. The Cell Cycle: Eukaryotes

  9. The Cell Cycle: Interphase • Cells spend 90% of their time “living” and growing. • The period of growth between divisions. • DNA is replicated when cell is triggered to begin reproduction. “INITIAL”

  10. Cell Cycle

  11. Cell Cycle: Mitotic Phase • Mitosis is divided into four phases: • Prophase • Metaphase • Anaphase • Telophase • New Cell Structures: • Centrioles (animal only) • Spindle Fibers

  12. Warm Up or Closure! • What is a chromosome made of? • Where are chromosomes found? • What is the “initial” or living stage of a cell called?

  13. Mitosis Animation • http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__mitosis_and_cytokinesis.html • Song: http://www.youtube.com/watch?v=pOsAbTi9tHw

  14. Cell Cycle: Mitotic Phase • Prophase: • 1st phase of mitosis • Replicated chromosomes become visible. • The nuclear envelope breaks down and spindle fibers begin to form. • A pair of centrioles help to organize the spindle fibers. PREPARE

  15. Cell Cycle: Mitotic Phase • Metaphase: • 2nd phase of mitosis • Chromosomes line up at the center of the cell. • Spindle fibers connect to the centromeres of each chromosome to the spindle. MEET IN THE MIDDLE

  16. Cell Cycle: Mitotic Phase • Anaphase: • 3rd phase of mitosis • Centromeres split, and the sister chromatids separate. • A complete set of chromosomes move to the opposite sides of the cell. APART

  17. Cell Cycle: Mitotic Phase • Telophase: • 4th (final) phase of mitosis • Chromosomes spread out into chromatin. • The nuclear envelope reforms around each group of chromosomes. • Spindles break apart. MAKES TWO

  18. Cell Cycle: Cytokinesis • Mitosis produces two nuclei, each with a complete set of chromosomes. • Cytokinesis completes the cell division by splitting one cell into two daughter cells. PLANT CELL ANIMAL CELL

  19. Warm Up or Closure! • What is the “initial” or living stage of a cell called? • What phase is when the chromosomes “meet in the middle” of the cell? • What phase “makes two” new nuclei?

  20. A B C D

  21. Regulating the Cell Cycle • How do cells know when to divide? • Cells use proteins to regulate the cell cycle. • Some cells respond to outside signals: • When one cell touches another they will stop dividing. • Used in healing. • Some cells use internal signals: • Internal proteins regulate the timing of the cell cycle.

  22. Cancer: Uncontrolled Cell Growth • Cancer develops when the body loses the ability to control growth in some of its cells. • Cancer forms a mass called a tumor. • Cancer cells can metastasize – or form secondary growths elsewhere in the body. • Cancer cells are called malignant – meaning they invade normal tissues. • Benign tumors are not cancerous. They do not spread to other body parts or come back after being removed. • See video

  23. http://learn.genetics.utah.edu/content/health/history/cancer/http://learn.genetics.utah.edu/content/health/history/cancer/

  24. Cancer

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