The phases of mitosis

Let's look more closely what happens when a cell divides. The phases of cell division are also called the phases of mitosis (cell division = mitosis). There are five phases of mitosis: prophase, prometaphase, metaphase, anaphase and telophase. Mitosis ends with cytokinesis, which is the split of the cell who has gone through all the phases listed above. As a result of cytokinesis, we get two new cells, or daughter cells, from one cell, the mother cell.

Prophase:

During prophase, the chromosomes condense, so they are packaged up more tightly. The centrosomes (on the picture: the orange rectangles with blue lines sticking out of them) migrate to the opposite poles of the cell and start to attach the microtubules to each other (microtubules = the blue lines). The attached microtubules are known as the mitotic spindle.

 

Prometaphase:

In this phase, the nuclear envelope fragments, and the microtubules start to attach to the kinetochore (the middle part of a chromosome).

  

   

Metaphase: 

During metaphase, the chromosomes that are now attached to the microtubules meet in the middle of the cell, forming the metaphase plate. The metaphase plate is one of the straightest lines in nature

Anaphase:

During anaphase, the sister chromatids start to move apart from each other. Each daughter cell will receive one sister chromatid, so that it's number of chromosomes is exactly the same as the number of chromosomes in the mother cell.

Telophase:

During telophase, nuclei start to form, and the organelles in the cell migrate to the opposite poles. The cell elongates, and a cleavage furrow forms (it is made of actin filaments).

Cytokinesis:

Cytokinesis is not considered a phase of mitosis, but it's vital in the process, because its not complete without it. During cytokinesis the cleavage furrow splits and we get two new daughter cells, that looke exactly like the mother cell.

Check out my video about the phases of mitosis here.