Cells need to reproduce when their surface area can no longer supply the much larger volume with nutrients and rid itself of metabolic wastes.
The first part of the cell cycle is called Interphase. Interphase is considered the resting stage of the cell. This definition can be misleading since the cell is not really resting, and it may last several days or even several years depending on the type of cell involved.

When the surface area to volume imbalance occurs the next phase begins. Here the genetic material replicates itself. This allows the cell to contain enough material to fully supply 2 cells upon division. The cellular organelles are also reproduced to allow for an adequate amount for the new cell being produced. After interphase Mitosis begins.
Mitosis is considered nuclear division, since the focus is upon the genetic material of the cell.

The first part of mitosis is Prophase. During prophase the nucleus begins to disappear. The chromatin pulls together and forms pairs of rope-like structures called chromatid pairs. These chromatid pairs are actually identical chromosomes. The chromatid pairs are held together by a structure called the centromere. Spindle fibers also begin to appear and along with the centrioles they migrate to the poles of the cell.

Metaphase begins when the chromatid pairs line up along the center of the cell. This makes it possible for the chromatids to position themselves so that they can migrate to the opposite poles of the cell.


Anaphase is the stage where this process occurs. The chromatid pairs split and the spindle fibers contract pulling each chromosome toward their pole. This process continues until the chromosomes arrive at each pole. The nucleus reappears and the spindle fibers disappear.

Telophase begins at this point and will continue until the cell splits into two. This split is called cytokinesis. We now have 2 daughter cells, each identical in the number and type of chromosomes. They are smaller than the mother cell and will begin to develop starting interphase again.

Overview of Mitosis- you should be able to name and explain what is going on in each stage of the flow chart below

Cell photographs