MITOSIS AND MEIOSIS

• Cell division

  The production of a “daughter cell” from a “parent cell”
• Cell division is the basis for reproduction of individual organisms
• Cell division allows the production of new individuals
• Cell division enables cell repair
• Cell division enables organismal growth
• Binary fission

  A type of asexual reproduction
• Binary fission can be observed in the majority of bacterial and archaeal species
• Binary fission is responsible for the production of bacterial generations
• Budding

  A type of asexual reproduction
• Budding can be observed in some bacterial and fungal species
• Budding creates an actual daughter cell
• Eukaryotic cell division


  Involves multiple stages
• Eukaryotic cell division can be classified into 2 types: mitosis and meiosis
• Eukaryotic cell division is responsible for tissue replacement and repair
• Eukaryotic cell division is the main reason for the growth of an organism
• Mitosis


  Occurs in the somatic cells of an organism
• Mitosis produces two daughter cells which are genetically the same
• Mitosis cells have a chromosome value of 2n
• Mitosis stages

  1. Interphase

  2. M-phase

  3. Cytokinesis
• Interphase


  Longest phase in the eukaryotic cell division
• Interphase prepares the cell for the upcoming division process
• Interphase is very important in the execution of cell division
• Interphase subphases

  1. G1

  2. S

  3. G2
• G1 phase


  The cell is active biochemically by preparing the chromosomes and proteins; the cell starts to grow significantly
• S phase


  Replicates the chromosomal content of the cell; the cell continues to grow
• G2 phase


  The centrosomes and other organelles have been replicated; final growth of the cell can be observed
• 1. phase


  The actual cell division stages
• 1. phase is responsible for the separation of the duplicated chromosomes
• 1. phase subphases

  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase
• Prophase


  Chromosomes will start to condense
• In prophase, the centrosomes form asters and release microtubules (spindles)
• In prophase, centrosomes will start to migrate to the opposite poles
• In prophase, the nuclear envelope will start to disappear
• Metaphase


  The centrosomes have reached the opposite poles of the cell
• In metaphase, chromosomes will align at the metaphase plate
• In metaphase, the spindle fibers are now attached to the kinetochores of the chromosomes
• Anaphase


  The cohesin of each chromosome will be cleaved
• In anaphase, the spindle fibers will start to shorten, pulling the sister chromatids apart
• In anaphase, the nonkinetochore spindles will lengthen as the kinetochore spindles shorten
• In anaphase, the cell will start to elongate