What is the first stage of mitosis?

The first stage of mitosis is prophase. During prophase, several key events occur that are essential for the subsequent steps of cell division. The chromatin, which is the loose form of DNA within the nucleus, begins to condense into visible chromosomes. Each chromosome is made up of two sister chromatids joined at a region called the centromere.

Additionally, the nuclear envelope starts to break down, allowing the spindle fibers to access the chromosomes. The centrosomes, which are the microtubule organizing centers, also move to opposite poles of the cell, where they begin to form the mitotic spindle. This spindle is crucial for the movement and alignment of chromosomes during the later stages of mitosis.

Recognizing prophase as the initial phase of mitosis is foundational in understanding cell division processes, as it sets the stage for the orderly separation of genetic material, which is critical for producing two genetically identical daughter cells.