Final answer:
The stage of mitosis, when sister chromatids separate and move to opposite poles of the cell, is known as anaphase.
Step-by-step explanation:
The stage of mitosis, when sister chromatids separate from each other and migrate to opposite poles of a cell, is called anaphase. During this phase, the pairs of sister chromatids are separated from one another, forming individual chromosomes once again. These chromosomes are then pulled to opposite ends of the cell by their kinetochores, as the microtubules shorten. This ensures that the two new daughter cells will contain identical genetic information.