Final answer:
The cytoskeleton structure necessary for the mitotic spindle is made of microtubules. These spindle fibers originate from centrosomes or MTOCs and are primarily responsible for chromosome segregation during cell division.
Step-by-step explanation:
The cytoskeleton structure required for the formation of the mitotic spindle during cell division is composed of microtubules. These microtubules polymerize to form spindle fibers that play a crucial role in the movement of chromosomes during both mitosis and meiosis. The spindle fibers originate from centrosomes, which in animal cells are associated with a pair of perpendicular structures known as centrioles. In plant cells, a similar structure called the MicroTubule Organizing Center (MTOC) takes on this role.
Microtubules are organized into different subsets within the spindle apparatus. Kinetochore microtubules connect to the kinetochores on chromosomes, ensuring that the chromosomes are segregated correctly into the two daughter cells. Meanwhile, astral microtubules assist in proper spindle orientation and regulation of mitosis.
To summarize, the mitotic spindle is a vital complex of cytoskeletal microtubules which ensures the accurate division of chromosomes into daughter cells. This process is critical to both mitotic and meiotic cell division in eukaryotic cells.