Mitosis - Cell Division During mitosis, the cell’s nucleus divides into two new nuclei. One copy of the DNA is distributed into each of the two daughter cells.
- Cell Division The Cell Cycle
The Cell Cycle Interphase Mitosis Cytokinesis Prophase Metaphas Anaphase Telophase Cytokinesis
Interphase
Interphase Interphase is like an intermission during a movie; it is the time between cell divisions. And much like during a movie intermission, a great deal of activity occurs during this phase. Interphase comprises most of the process known as the cell cycle. During interphase, the cell enlarges and carries out the metabolic tasks such as taking in food and giving off wastes, replicating chromosomes, and producing organelles. This is the longest phase. The cell's sole purpose seems to be to prepare itself to reproduce. Remember, Interphase is not a phase of mitosis.
Prophase
Prophase After interphase is complete, prophase, the first stage of mitosis, begins. During prophase the replicated chromosomes (chromotids) shorten, thicken and coil. They bunch up so much that they become visible through a microscope. Once this happens, the cell has reached prophase (first phase). The nuclear envelope breaks up, and small fibers, called spindle fibers, are formed.
Metaphase
Metaphase The chromatids become attached to the spindle fibers and line up at the middle of the cell during metaphase (middle phase). One way to remember this is middle and metaphase both start with m. At this stage, you can see that each chromosome is made up of two strands, or chromatids, and each strand is identical to the other.
Anaphase
Anaphase The chromatids separate from each other (each is now a chromosome) and are gradually pulled apart during anaphase. The cell becomes longer. The spindle fibers begin to break down. One way to remember this phase is that the chromosomes are being pulled away from the center. Away and anaphase both start with a.
Telophase
Telophase The last phase is telophase (end - phase). One set of chromosomes becomes grouped at each end of the cell; the nuclear envelope develops around each group, and the chromosomes uncoil. Following telophase, the nuclei are separated from each other by the cell membrane. This is done during cytokinesis. One way to remember this phase is that mitosis is complete and the chromosomes want to tell all of their friends. Tell and telophase both start with t.
Cytokinesis
Cytokinesis Cytokinesis is not considered a phase. It begins during telophase as the new cell membrane forms. The cell membrane pinches inward to divide the cell into two new cells. In plant cells, a cell wall forms across the width of the cell to separate the nuclei from each other.