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Stages of the Cell Cycle - Mitosis (Metaphase, Anaphase and Telophase)

Updated on February 4, 2017

The Mitotic Cell Cycle

Mitosis is vital to multicellular life on our planet. This diagram summarises the whole process.
Mitosis is vital to multicellular life on our planet. This diagram summarises the whole process.

Metaphase, Anaphase and Telophase

Part one of this series looked at the cycles within cycles that make up the existence of a cell. Whilst taking up such a small percentage of the overall cell cycle, mitosis is one of the most important series of events in the life of a cell. We shall now examine how the condensed sister chromatids (when chromosomes look like a big X they are called sister chromatids - the part where the arms of the x 'join' is known as the centromere) align along the metaphase plate, separate and are repackaged into nuclei

During Metaphase, the sister chromatids MEET at the metaphase plate
During Metaphase, the sister chromatids MEET at the metaphase plate | Source

Metaphase

Metaphase sees the chromosomes line up along the metaphase plate. Here, the spindle fibres attach to the centromeres of the sister chromatids. These fibres act as tow cables to separate the sister chromatids.

Metaphase is one of the most easily-recognisable phases of the cell cycle, and is also the location of a key cell cycle checkpoint - the mitotic spindle checkpoint. Anti-cancer compounds such as taxanes (docetaxel and paclitaxel(Taxol)) work by inhibiting the destruction of the spindle fibres, thus preventing movement through the mitotic spindle checkpoint. This results in cell death

During Anaphase, the chromatids move APART
During Anaphase, the chromatids move APART | Source

Anaphase

The major event of Anaphase is the sister chromatids moving to opposite poles of the cells, due to the action of the condensing spindle fibres. The chromatids only start separating when the pressure is sufficient to split the centromere. At this point, each chromatid effectively becomes a chromosome. The moving sister chromatids form a V shape as they move through the cytoplasm. This is because the centromeres are pulled by the spindle fibres, and lead the rest of the chromatid.

Telophase sees the nuclear envelope reform around the chromosomes at opposite poles of the cell
Telophase sees the nuclear envelope reform around the chromosomes at opposite poles of the cell | Source

Telophase

Telophase basically describesthe series of events that sees new nuclear envelopes form around each set of sister chromatids - now located at the poles of the cell. Also:

  • The spindle breaks down
  • Chromosomes unravel and so are invisible under light microscopy

The cell is now preparing for the final stage in the cell cycle, cytokinesis

Cytokinesis

Cytokinesis is technically a separate set of events to mitosis. It describes the series of events seen when the cell splits into two. This process starts as a cleavage furrow between the cells, making it look like the figure 8. This furrow extends until the whole cell has split. With identical genetic information, each cell can perform the same task as the parent cell.

A couple of details need clarification about the differences between plant and animal mitosis:

  • Plant cells do not have centrioles. The fibres that make up the spindle are synthesised directly in the cytoplasm
  • All animal cells are capable of mitosis and cytokinesis. Plant cells focus their growth to specialised regions called meristems - found at the root tips and shoot tips.
  • As plant cells need to synthesis the cell wall during cytokinesis, they do not create a cleavage furrow 'from the outside in.' Cytokinesis starts where the spindle equator was, and continues with new cell membrane and new cell wall material being laid down along this plate.

Stages of Mitosis (narrated)

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      anthony moss 22 months ago

      auussoomm

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      dave 2 years ago

      spelling errors

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      Adam 3 years ago

      This customizable and printable flash card set is helpful for memorizing the stages of mitosis: http://stemsheets.com/science/stages-of-mitosis-fl...

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      madhuri 4 years ago

      good understanding of concepts

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      Eric Kasleboom 5 years ago

      well done relly loved it

    • Pedro Silva profile image

      Pedro Silva 5 years ago from Portugal

      Well done! I'm on the last year of secondary school and I learned even more with these lesson.

    • Steve LePoidevin profile image

      Steve LePoidevin 5 years ago from Thailand

      As always,another well-explained lesson. Will have to pass these on to my biology teacher friends.

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      Shasta Matova 5 years ago from USA

      Great lesson with interesting photos and video. Voted up.