What happens to the nuclear envelope during telophase?

During telophase, the nuclear envelope reforms around each set of separated sister chromatids, which are now considered individual chromosomes. This process marks the end of nuclear division, or mitosis. As the chromosomes begin to decondense back into chromatin, the nuclear envelope re-establishes its structure, creating two distinct nuclei within the newly formed daughter cells.

The reformation of the nuclear envelope is crucial because it sets the stage for the nucleus to function normally again, with the necessary encapsulation of genetic material. This reorganization helps ensure that the genetic information in each daughter cell is protected and organized for future cellular processes.

Other options, such as dissolution or expansion, do not accurately depict what occurs during this phase. While the nuclear envelope does dissolve during the earlier phase of mitosis (prophase), during telophase, it is instead reconstituted. The idea of condensation is also inaccurate here, as condensation refers to the process of chromosomes becoming more tightly packed during earlier stages of cell division, not for the nuclear envelope itself.