What do you need to enter prophase?

To transition into prophase, the essential requirement is to have a copied set of chromatids. Before cells enter prophase, they must have completed DNA replication during the S phase of the cell cycle. This replication results in each chromosome consisting of two identical sister chromatids attached at a region called the centromere.

During prophase, these duplicated chromosomes become visible as they condense and start to organize within the cell. They are no longer in their relaxed chromatin form but are tightly packed, allowing for easier segregation later in mitosis. The spindle apparatus begins to form, but it is crucial that the chromosomes are in duplicated form, as this ensures that each daughter cell will receive an identical set of genetic material when the cell divides.

In summary, the transition into prophase is contingent on having the copied chromosomes, which are essential for proper mitotic division.