During telophase of Mitosis nuclear membranes of two separated nuclei are formed around each set of chromosomes.
Explanation:
Mitosis is the process of cell division part of the cell cycle. Mitosis is classified into four phases which are prophase, metaphase, anaphase and telophase. In prophase the nucleolus disappears, chromosomes start to contents and the mitotic spindle starts to appear and bind to the kinetochore of centromere of the chromosomes. In metaphase nuclear envelope breaks down and the chromosomes becomes fully condensed and organized on the metaphase plate in the middle of the nucleus, during anaphase chromosomes are pulled back to their centromeres with the help of spindle fibers and during telophase the chromosomes starts to decondense, the nucleous reappears and nuclear membrane reforms and spindle starts to disappear.