Prophase (Lat. Pro - Before, Gr. Phasis - Phase)

Prophase (from Latin pro - before and Greek phasis - phase) is the first stage of mitosis, which precedes metaphase, anaphase and telophase. At this stage, compaction of chromatin threads occurs, the appearance of separate chromosomes and the formation of a spindle - a special structure that helps move chromosomes during cell division.

Prophase is divided into several phases, each of which is characterized by certain events. In early prophase, chromatin becomes compacted, which begins to curl and form chromosomes visible under a microscope. Each chromosome consists of two chromatids connected by a centromere.

During middle prophase, chromosomes actively move in the nucleus and line up along the equatorial plane of the cell. At this moment, the formation of a fission spindle begins, which consists of microtubules. By stretching between the poles of the cell, the spindle helps move chromosomes to metaphase.

Late prophase is characterized by complete division of the nucleus into two parts and attachment of spindle microtubules to the centromeres of chromosomes. At this point, the transition to metaphase occurs, in which the chromosomes are located on the equatorial plane and are ready to divide into two daughter cells.

Thus, prophase is an important stage of mitosis, during which the cell prepares for division. Chromatin compaction, chromosome formation, and spindle formation all work together to ensure the precise division of genetic material between daughter cells.