What drives the movement of chromosomes during mitosis?

The movement of chromosomes during mitosis is primarily driven by the dynamic behavior of microtubules at the kinetochores, which are specialized protein structures on the chromosome where microtubules attach. During mitosis, the spindle fibers, composed of microtubules, undergo processes of polymerization and depolymerization, allowing them to effectively pull the chromosomes apart toward opposite poles of the cell.

As the chromosomes align at the metaphase plate and then begin to separate, the addition and subtraction of protein subunits at the kinetochore regulate this movement. The microtubules exert force on the kinetochores, and as they shorten, they pull the chromosomes apart. This precise mechanism ensures that each daughter cell receives an identical set of chromosomes during cell division.

Understanding this process highlights the importance of the kinetochore's interaction with the spindle apparatus, illustrating how molecular dynamics and cellular architecture work together to facilitate accurate chromosome segregation in mitosis.