Briefly describe the process during mitosis called anaphase.

Anaphase follows metaphase in the process of mitosis. Mitosis is the process by which a cell divides into two identical daughter cells. 

At the conclusion of metaphase, the chromosomes have been replicated and have been lined up across the center of the cell.

In anaphase, the chromosomes are pulled apart towards the two poles of the cell. In successful mitosis, one copy of each chromosome ends up on either side of the cell. Significant cell lengthening also occurs during this phase (the cell becomes less circular and more oval shaped). 

Both the chromosome migration and cell lengthening are accomplished by different actions of the cell spindle. The chromosomes are pulled to the poles by the shortening of kinetochore microtubules, while the cell is lengthened by the action of non-kinetochore microtubules lengthening.

Anaphase is followed by telophase.