Cell Division (Interphase+Mitosis)

Remember: Cell division (mitosis) will occur when an organism needs to repair, grow, or reproduce

The Cell Cycle: has two processes

  • Interphase - when a cell is resting/preparing for division

  • Mitosis/Cytokinesis - the process of the cell actually splitting up into 2 daughter cells/the equal split of cytoplasm and the cells organelles

A bit more info about Mitosis:

  • the parent cell is the one that divides, so 2 exact daughter cells are created

  • the daughter cells are the exact copy of the parent cells, which allows for genetic continuity

The Cell Cycle (Broken Down)

Interphase

  • G0 phase - Cell is in resting phase, and isn’t growing

  • G1 phase - Check point 1, and cell prepares for division

    -it prepares for division by doubling in size, and the centrosome ( a cellular structure that helps in cell division) doubles

  • S phase - DNA replicates. Chromatin condenses into chromosomes, and chromosomes replicate to form chromatids

  • G2 phase - Check point 2 - checks that DNA was copied properly

Mitosis - has 4 stages: Prophase, Metaphase, Anaphase, and Telophase (PMAT)

  • Prophase:

    - centrosomes move to opposite sides of cell

    - doubled chromatids join at the centromere to form sister chromatid

    - nucleus disappears

    - spindle fibers called microtubules come from centrosomes and attach to chromatids


  • Metaphase:

    - sister chromatids line up along the metaphase plate (an imaginary line in middle of cell)

    - sister chromatids are held perpendicular to the microtubules


  • Anaphase:

    - each side of the sister chromatids is pulled towards the centrosomes, as the spindle fibers shorten via the centromere


  • Telophase:

    - spindle fibers disappear

    - nucleus reforms

    - there are temporarily 2 nuclei in one cell

    - chromatid uncoil into chromatin

    - cytoplasm pinches at the equator (center of cell) creating a furrow


  • Cytokinesis:

    - the cell splits into 2 daughter cells, and cytoplasm and organelles of the cell are evenly distributed to the 2 daughter cells