What is the final phase of mitosis in which the cell seals off after chromosome separation?

The final phase of mitosis is telophase, during which several key events occur that signify the conclusion of the mitotic process. After the chromosomes have been successfully separated and pulled to opposite poles of the cell during anaphase, telophase involves the reformation of the nuclear envelope around each set of chromosomes. This marks the transition from a single cell with duplicated chromosomes to two distinct nuclei.

During telophase, the chromosomes begin to de-condense back into their less tightly coiled chromatin form, making them less visible under a microscope. Additionally, during this phase, the mitotic spindle, which is responsible for the separation of chromosomes, starts to disassemble. The final event in this phase often includes the initiation of cytokinesis, where the cell's cytoplasm is divided, ultimately leading to two separate daughter cells.

Understanding telophase is important in the context of the entire cell cycle, as it represents not only the closing of mitosis but also sets the stage for the subsequent cellular processes that prepare for cell division.