Cell division ; SCI 3RD QTR.

• Mitosis - is a process of nuclear division wherein two genetically identical daughter cells with the same number of chromosomes as their parent cell are produced.
• Meiosis - another type of cell division that generates sex cells (gametes).
• Chromosomes - are darkly stained bodies within the nucleus consisting of highly coiled and condensed strands of DNA
• Cell cycle - Living and actively dividing cells
• Interphase (non dividing stage) - the period of growth with DNA replication.
• 3 phases of interphase:

  1. Gap 1 phase - the newly produced daughter cells increase in size, and They prepare themselves for DNA replication.
  2. Synthesis - considered as the most critical part of interphase.
  3. Gap 2 phase - is the second gap wherein cells continue to grow and synthesize RNA and proteins
• Mitosis (dividing stage) - the period of reproduction or the actual division of the nucleus.
• Cytokinesis - is the division of the cytoplasm and the plasma membrane
• Prophase - chromosomes have already been duplicated
• Metaphase - all chromosomes are aligned at the center (or equator) of the cell
• Anaphase - the centromere splits, and repulsion of the two sister chromatids occurs.
• Telophase - the opposite of prophase and the last stage of mitosis, chromosomes have reached opposite poles
• Stages of meiosis:

  1. Meiosis 1 - known as the reproduction stage The synapsis and crossing-over occur

  Crossing-over - is the process wherein homologous chromatids exchange genetic material to ensure greater variety in gamete formation.

  Meiosis 2 - is a division stage similar to mitosis, except that the cell does not undergo interphase anymore.