What is the function of the mitotic spindle apparatus?
The mitotic spindle apparatus serves to pull duplicated chromosomes apart.
When a dividing somatic cell has duplicated its DNA it can proceed to mitosis. During mitosis the pairs of copied chromosomes (condensed packages of DNA) have to be pulled apart in order to form two genetically identical daughter cells. This is where the mitotic spindle comes in.
Early in mitosis (prophase) the mitotic spindle is formed. These are microtubuli that are on one side attached to a protein structure, the centrosome. There are two of these centrosomes that move to oppsite poles of the cell. On the other end, the microtubuli attach to a complex of proteins (the kinetochore) at the middle of one of the replicated chromosomes. The microtubuli and associated proteins are called the mitotic spindle.
Later in mitosis (anaphase) the chromosome pairs synchronously separate and each chromosome is pulled toward the spindle pole it is attached to. The task of the mitotic spindle is now completed and two genetically identical daughter cells are formed.