Nucleolus reappears in telophase of mitotic divisions only.

Answer

### Step-by-Step Solution:

1. **Understanding the Nucleolus**: The nucleolus is a structure within the nucleus that is involved in ribosome production. It is not a membrane but rather a dense region where ribosomal RNA (rRNA) is synthesized and ribosome assembly begins.

2. **Nucleolus Disappearance in Mitosis**: During the prophase stage of mitosis, the nucleolus disappears. This is necessary for the chromosomes to condense and become visible, allowing them to be properly segregated during cell division.

3. **Karyokinesis and Cytokinesis**: Karyokinesis refers to the division of the nucleus, while cytokinesis is the division of the cytoplasm. Both processes occur after prophase, leading to the formation of two daughter cells.

4. **Nucleolus Reappearance in Telophase**: The nucleolus reappears during the telophase stage of mitosis. This occurs after the chromosomes have been separated and the nuclear envelope begins to reform around each set of chromosomes in the daughter cells.

5. **Meiosis Comparison**: The statement claims that the nucleolus reappears in telophase of mitotic divisions only. However, this is incorrect. The nucleolus also disappears during prophase I of meiosis and reappears during telophase II of meiosis.

6. **Conclusion**: Therefore, the statement is false. The nucleolus reappears in both mitosis (during telophase) and meiosis (during telophase II).

### Final Answer:
The statement "Nucleolus reappears in telophase of mitotic divisions only" is **false** because the nucleolus also reappears during telophase II of meiosis.