meiosis and mitosis

• Genetics


  The study of heredity and the variation of inherited characteristics

  
• Cell division


  • Growth and repair
• Some cells once fully formed do not undergo cell division, such as nerve cells and muscle cells
• Since you can never re-grow or repair these types of cells once they are mature, you must take care of the ones you have
• Rudolf Virchow

  Proposed cell theory
• Cell theory


  • "Cells arise only from pre-existing cells"
  • "No new cells will be formed without pre-existing cells and no new organisms will be formed without pre-existing organism"
  • "All cell undergo cell division"
• Like begets like

  • Organisms reproduce asexually, creating genetic copies of the parent and each other
  • Organisms reproduce sexually, creating a variety of offspring
• Cellular reproduction in unicellular organisms (prokaryotic cells)

  1. Bacterial cells divide by binary fission (split into two)

  2. Genetic material replicates

  3. Chromosomes pulled to opposite poles

  4. Cell wall constricts and divides the cell

  5. New daughter cells are identical in content
• Cellular reproduction in multicellular organisms (eukaryotic cells)

  1. Means for reproduction of new tissues or body parts during growth and development

  2. Means to replace worn-out and damaged cells

  3. Means to produce new plants or animals in asexually-reproducing organisms
• Cellular reproduction


  • Cellular growth and maturation (normal size, assembly of organelles, accumulation of energy and materials, replication of genetic content)
  • Cell division (systematic and equal division of genetic material into two daughter cells)
• Cells need to grow and mature prior to cell division
• Checkpoint failure often causes mutations and genomic arrangements resulting in genetic instability, a major factor of birth defects and development of many diseases - cancer biology
• Mitosis


  A type of cell division
• Mitosis is a type of cell division where one cell divides to form two identical daughter cells with the same number of chromosomes as the parent cell.
• Cell division occurs when a parent cell divides into two or more daughter cells, allowing growth, repair, and reproduction.
• The nucleus is the control center of the cell, containing genetic material (DNA) that determines an organism's characteristics.