Prophase I

• In the nucleus: Chromatins begin to shorten and condense to form chromtids. Chromatids then form chromosomes.
• In the cytosol: centrioles move to the edge of the cell and radiate a network of fibres called spindles
• Nuclear membrane starts to dissolve
• The matching pairs of chromosomes will line up (synapsis) and exchange DNA. This process is called crossing over.