Intro
 
 
Mitosis is the process of forming, generally, identical daughter cells by copying and dividing the chromosomes. Commonly the two processes of cell division are confused. Mitosis deals only with the separation of the chromosomes and organelles into daughter cells.  
During mitosis replicated chromosomes are positioned near the middle of the cytoplasm and then separeted so that each daughter cell receives a copy of the original DNA (if you start with 46 in the parent cell, you should end up with 46 chromosomes in each daughter cell). To do this cells use microtubules (referred to as the spindle apparatus) to "pull" chromosomes into each "cell". Animal cells (except for a group of worms known as nematodes) have a centriole. Plants and most other eukaryotic organisms lack centrioles. Prokaryotes, lack spindles and centrioles; the cell membrane assumes this function when it pulls the by-then replicated chromosomes apart during binary fission. Cells that contain centrioles also have a series of smaller microtubules, the aster, that extend from the centrioles to the cell membrane. The aster is thought to serve as a brace for the functioning of the spindle fibers.  
 
On this website, you will be able to see the process of mitosis in a eukaryotic animal cell with 4 chromosomes.  
The phases of mitosis are sometimes difficult to separate. Remember that the process is a dynamic one, not the static process displayed of necessity in a textbook.  
 
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