Mitosis: The Dance of the

Chromosomes

Once Interphase is done the cell is ready to begin Mitosis.

Mitosis is when the cell divides

Mitosis consists of 4 stages:

1. Prophase2. Metaphase3. Anaphase4. Telophase

Finishes with cytokinesis

Can you spot each stage?

Prophase

Chromosomes thicken, forming coils upon coils, & become visible.

Nuclear membrane starts to disintegrate – giving the cell plenty of room to sort out chromosomes.

ProphaseCentrioles – tiny structures that help to organize microtubules.

These cylindrical bodies start to move away from each other, towards opposite ends of the cell.

ProphaseThe centrioles will spin out a system of microtubles known as spindle fibers.

These spindle fibers will grow toward the chromosomes.

Metaphase Chromosomes begin to line up.

Notice how nice and orderly they’ve become.

The spindle fibers which are attached to the centromeres line up the chromosomes at the middle of the cell along the metaphase plate.

Anaphase The sister chromatids of each chromosome separate at the centromere and migrate to opposite poles.

A “tug of war” begins with the chromosomes pulled apart at the centromere by the spindle fibers.

TelophaseThe final phase of MitosisChromosomes are on opposite sides of cell.

Nuclear membrane forms around each set of chromosomes and the nucleoli reappear.

CytokinesisSeparate from MitosisThe cytoplasm and its contents divide into 2 individual daughter cells.

Cell splits along a cleavage furrow.

After telophase and cytokinesis, the 2 daughter cells return to interphase and start the cell cycle all over again.

Cytokinesis is different in plant cells!!!!, no cleavage furrow instead a cell plate forms down the middle.

Purpose of Mitosis

1. To produce daughter cells that are identical copies of the parent cell.

2. To maintain the proper number of chromosomes from generation to generation.