Chapter 2

    Cards (32)

    • Specialized cells
      Different types of cells that make up complex organisms like animals and plants
    • Examples of specialized cells in animals
      • Sperm cells
      • Muscle cells
      • Nerve cells
    • Examples of specialized cells in plants
      • Root hair cells
      • Phloem cells
      • Xylem cells
    • Sperm cell
      • Has half the genetic material of a normal adult cell
      • Has a flagellum to swim
      • Is streamlined to swim
      • Has many mitochondria for energy
      • Has digestive enzymes to break into egg
    • Specialized cells
      Have a specific role, shape, structure and organelle composition to fulfill that role
    • Differentiation
      The process by which a cell changes to become specialized
    • Zygote
      The single fertilized egg cell that life starts from
    • Cell differentiation
      1. Zygote divides by mitosis
      2. Cells remain identical at first
      3. Cells then undergo differentiation
      4. Cells become specialized like muscle, skin, nerve, red blood
    • Stem cells
      Cells that can repeatedly divide by mitosis and differentiate into different specialized cell types
    • Stem cells
      Cells that can divide by mitosis to form more cells and can differentiate into specialized cells
    • Stem cells
      • Can divide by mitosis to form more cells
      • Can differentiate into specialized cells
    • Human life starts
      1. Sperm cell fertilizes egg cell
      2. Forms zygote
      3. Zygote divides by mitosis repeatedly
      4. Forms embryo
      5. Embryonic stem cells can differentiate into any cell type
      6. Cells continue to divide and differentiate
      7. After 9 months, baby is born
    • Embryonic stem cells

      Stem cells found in the embryo that can differentiate into any cell type
    • Adult stem cells
      Stem cells found in adults that can only differentiate into a narrow range of cell types
    • Adult stem cells
      • Stem cells found in bone marrow that can differentiate into blood cells
    • Plant stem cells

      Stem cells found in meristematic tissues in plants that can differentiate into all the cells and tissues the plant needs
    • Plant stem cells persist for the plant's entire life, unlike embryonic stem cells which disappear by the time we're fully developed
    • Stem cells
      Cells that can divide by mitosis to produce more cells and can differentiate into different types of specialized cells
    • Types of stem cells
      • Embryonic stem cells
      • Adult stem cells
    • Embryonic stem cells

      • Found in the early embryo
      • Can differentiate into any type of specialized cell
    • Adult stem cells
      • Found in the bone marrow
      • Can only differentiate into different types of blood cells
    • Many conditions are due to faulty cells that are damaged or don't work properly
    • Using stem cells to treat conditions
      1. Extract stem cells
      2. Grow them in a lab
      3. Stimulate them to differentiate into desired cell type
      4. Transplant into patient
    • Conditions that could be treated with stem cells
      • Diabetes
      • Paralysis
      • Sickle cell anemia
    • Using embryonic stem cells
      • Limited supply
      • Ethical issues
    • Using embryonic stem cells
      • Risk of rejection by patient's immune system
    • Adult stem cells
      • Easy to obtain
      • Won't cause rejection
    • Limitations of adult stem cells
      • Can only differentiate into blood cells
    • Potential risks of using stem cells include virus transmission and tumor development
    • Ethical objection to using embryonic stem cells
      Embryos have potential for human life
    • Embryos used for research are usually unwanted from fertility clinics that would otherwise be destroyed
    • Stem cell research is tightly regulated in the UK with strict rules for scientists to follow
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