Telophase is the final stage of nuclear division, known as karyokinesis, occurring in both mitosis and meiosis. It prepares the cell for division into two new daughter cells by establishing two distinct nuclei. This phase reverses many structural changes from earlier stages of cell division.
Chromosomal and Nuclear Changes
During telophase, the replicated chromosomes arrive at their respective poles at opposite ends of the cell. They begin to decondense, uncoiling from their compact forms into a more extended, thread-like structure called chromatin. This decondensation makes the genetic material accessible for cellular processes in the subsequent interphase.
Simultaneously, new nuclear envelopes form around each cluster of decondensing chromosomes at both poles of the cell. These new envelopes reassemble from components of the parent nuclear envelope and fragments of the endoplasmic reticulum. This re-formation creates two separate nuclei within the single cell.
Spindle fibers that separated chromosomes in earlier stages depolymerize and largely disappear. Nucleoli, which had vanished during prophase, reappear within each new nucleus. Their reappearance signals the resumption of ribosome production, essential for protein synthesis in the upcoming daughter cells.
Significance for New Cells
Telophase processes prepare the genetic material for the next cell cycle phase. The reformation of the nuclear envelope around each set of chromosomes protects the segregated genetic information and establishes distinct nuclear compartments. This protective barrier maintains genomic integrity and regulates molecular transport between the nucleus and cytoplasm.
Chromosome decondensation allows the DNA to transition back to its functional interphase state, making it available for gene expression and DNA replication. This ensures the genetic instructions are readily utilized by the cell. Telophase completes the precise segregation of genetic material, ensuring each new daughter cell receives a complete and functional set of chromosomes.
Following Cytoplasmic Division
While telophase concludes nuclear division, cytokinesis, the physical division of the cell’s cytoplasm, begins during or immediately after. This process splits the original cell into two daughter cells. It ensures that genetic material, cellular organelles, and cytoplasm are distributed between the newly formed cells.
Telophase sets the stage for cytokinesis by providing two distinct nuclei at opposite ends of the cell. This arrangement facilitates the equitable partitioning of cellular components. While telophase is the final step of nuclear division, cytokinesis completes the entire cell division process, resulting in two independent, functional cells.