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Cellular Reproduction

Cellular Reproduction. How Do Cells Receive Nutrients?. Cell Membrane The membrane allows in: Food Water Oxygen. The Cell Membrane. Selectively permeable – allows only certain materials to pass through.

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Cellular Reproduction

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  1. Cellular Reproduction

  2. How Do Cells Receive Nutrients? • Cell Membrane • The membrane allows in: • Food • Water • Oxygen

  3. The Cell Membrane • Selectively permeable – allows only certain materials to pass through. • Diffusion – the movement of molecules from areas of higher concentration to areas of lower concentration • Osmosis – the movement of molecules from areas of higher to areas of lower concentration through the cell membrane.

  4. The Cell Membrane • Three types of solution • Hypotonic • Note: = Water = Concentration

  5. The Cell Membrane • Three types of solution • Isotonic • Note: = Water = Concentration

  6. The Cell Membrane • Three types of solution • Hypertonic • Note: = Water = Concentration

  7. The Cell Membrane • Three types of solutions • Hypotonic Isotonic Hypertonic • The concentration of water outside of the cell is: • Higher Same Lower

  8. The Cell Membrane • Three types of solutions • Hypotonic Isotonic Hypertonic • The concentration of dissolved substance outside of the cell is: • Lower Same Higher

  9. The Cell Membrane • Three types of solutions • Hypotonic Isotonic Hypertonic • The cell contents will: • Swell Stay the same Shrink

  10. The Cell Membrane • The concentration (amount) of dissolved substance affects the movement of water into and out of the cell.

  11. The Cell Membrane • Homeostasis – the ability of an organism to maintain a constant internal balance even when the conditions around it change. • Examples: • Turgor Pressure – the force of the cell contents pushing against the cell wall

  12. The Cell Membrane • Passive Transport – the movement of substances through the cell membrane without using energy. • Active transport – the movement of molecules from areas of lower to higher concentration with the use of energy.

  13. The Cell Membrane • Protein Molecules Lipid Molecules

  14. Surface Area to Volume Ratio • Cell Diameter increases 10 times • Surface Area increases 100 times • Volume increases 1000 times

  15. Surface Area to Volume Ratio • Double the cell size (2 times) • 8 times more nutrients required • 8 times more waste to excrete • Surface area increase only 4 times • Cell starve to death or be poisoned

  16. Why is it important to have many small cells rather than one Larger cell? • Larger cell has: • Difficulty in receiving enough nutrients and oxygen • Difficulty in removing wastes • One copy of DNA

  17. Cell Division Cell divides into two daughter cells

  18. Mitosis • Process by which the nucleus of the cell is divided into two nuclei, each with the same number and kinds of chromosomes as the parent cell.

  19. Interphase • G1 phase • Cellular Growth • Development • S phase • DNA Replication • Protein synthesis • G2 phase • Synthesis of organelles • Materials for cell division

  20. Interphase

  21. Chromosomes • Contain the genetic information (DNA) that is passed from one generation of cells to the next.

  22. Chromosomes • DNA • Proteins (histones)

  23. Chromosome Structure Sister Chromatid Centromere DNA

  24. Number of Chromosomes

  25. Prophase Longest (50 - 60%) • Appearance of chromosomes • Nucleolus disappears • Nuclear membrane breaks down • Centrioles separate and migrate to opposite poles of cell • Spindle fibers from the centrioles attach to the centromeres • Chromatin coils up (shortens) into chromosomes

  26. Prophase

  27. Metaphase • Chromosomes line up across center (equator) of cell • Spindle fibers from centromere to centrioles Shortest

  28. Metaphase Chromosome Centriole Spindle Fiber

  29. Anaphase • Sister Chromatids split at Centromere • Individual Chromosomes move toward poles • Chromatid pairs from each chromosome separate from each other • Chromatids are pulled apart by the shortening of the microtubules in the spindle fibers

  30. Anaphase

  31. Telophase Final Phase • Spindle fibers breakdown • Chromosomes uncoil into Chromatin • Nuclear envelope (membrane) reforms • Nucleolus becomes visible • Chromosome reach the ends of the cell • The centrioles double • The cytoplasm is divided

  32. Telophase

  33. Mitosis in Whitefish and Onion

  34. Cytokinesis • The process by which the cytoplasm divides, forming two new cells.

  35. Cytokinesis • Animals • Cell membrane • pinches inward • Plants • Cell plate

  36. Result of Mitosis Two cells that are identical to each other.

  37. Cell Theory • Developed by Robert Hooke • Came up with the name cells • Encouraged other scientists to look for cells in their research • Cell theory is made up of three main ideas:

  38. Cell Theory • All organisms are composed of one or more cells. • Most organisms are multicellular • Cells are the basic units of structure and function in organisms • All cell arise from existing cells • Cell theory states that a cell divides to form two identical cells

  39. Cancer

  40. “When Cell Division Goes Bad” Cancer

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