What is the name of the stage of mitosis in which the nuclear envelope forms, the nucleolus appears, and the microtubules disassemble? A Anaphase B Prophase C Telophase D Metaphase
The correct answer and explanation is:
The correct answer is C. Telophase.
During telophase, the final stage of mitosis, several key events occur that signify the end of mitotic division and the preparation for the return to interphase. The most notable events include:
- Formation of the Nuclear Envelope: As the chromosomes begin to uncoil into chromatin, a new nuclear envelope starts forming around each set of separated chromosomes. This process re-establishes the distinct nuclear boundaries that were broken down during earlier stages of mitosis.
- Reappearance of the Nucleolus: The nucleolus, which disappeared during prophase, reappears in each daughter nucleus. The nucleolus is the region where ribosomal RNA (rRNA) is synthesized and where ribosome assembly begins. Its reappearance signals that the cell is ready to resume its normal functions, including protein synthesis.
- Disassembly of Microtubules: The microtubules, which play a crucial role in the separation of chromosomes during earlier stages of mitosis, begin to disassemble in telophase. The spindle fibers that were responsible for pulling the chromosomes apart lose their structure as the cell prepares to complete division.
Telophase marks the near end of mitosis, followed by cytokinesis, which is the actual division of the cytoplasm, leading to the formation of two separate daughter cells. These daughter cells will each have a complete set of chromosomes and a newly re-formed nucleus.
Thus, telophase represents the stage where mitosis effectively concludes, setting the stage for the cell to return to a resting or interphase state before it can begin the next round of division or normal metabolic activities.