In which cell cycle phase does the chromatin condense and the nucleus disappear?

In the cell cycle, chromatin condenses and the nucleus disappears during prophase. This phase marks the beginning of mitosis, where the chromatin, which is in a less compact form during interphase, becomes tightly packed into visible chromosomes. As the chromatin condenses, it facilitates the proper segregation of genetic material during cell division. Additionally, the nuclear envelope breaks down in prophase, leading to the disappearance of the nucleus. These changes are essential for ensuring that each daughter cell receives an accurate copy of the genetic material during cell division.

In contrast, during metaphase, chromosomes are aligned in the center of the cell, and while they are visible, the nucleus has already disappeared. Anaphase is characterized by the separation of sister chromatids as they are pulled towards opposite poles of the cell. Interphase is the phase where the cell prepares for division, but the chromatin is not condensed, and the nucleus is intact. Therefore, prophase is specifically marked by both the condensation of chromatin and the loss of the nuclear envelope.