1. Separation of Sister Chromatids:

* The centromeres of each duplicated chromosome (sister chromatids) separate. This is driven by the shortening of microtubules attached to the kinetochores, which are protein complexes on the centromeres.

* The sister chromatids are now considered individual chromosomes and are pulled apart by the microtubules towards opposite poles of the cell.

2. Elongation of the Cell:

* As chromosomes move to the poles, the spindle fibers between the poles elongate. This is achieved by the polymerization of tubulin subunits, the building blocks of microtubules.

* This elongation helps to push the poles further apart, contributing to the overall stretching of the cell.

3. Formation of the Cleavage Furrow (in animal cells):

* A contractile ring of actin and myosin filaments forms on the inside of the cell membrane at the equator of the cell.

* This ring begins to contract, pinching the cell membrane inward, forming a cleavage furrow. This furrow deepens and eventually pinches the cell completely in two.

4. Continued Microtubule Depolymerization:

* While some microtubules elongate, others depolymerize, releasing tubulin subunits.

* This depolymerization contributes to the separation of the poles and the movement of chromosomes.

In summary, anaphase is the stage of mitosis where the duplicated chromosomes are separated and pulled apart to opposite poles of the cell, driven by the shortening of microtubules and the elongation of the spindle fibers. The cell also begins to elongate and form a cleavage furrow in preparation for cell division.