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In the cell cycle, at the end of interphase M-phase initiates. Prior to the initiation of Mitotic phase (M-phase) cell prepares for cell division by the process called Prophase.

There are two stages of prophase:

  1. Early prophase:
    • Replicated centrioles begin to move towards the pole of the cell
    • Replicated chromosomes become condensed and visible
    • Nucleolus becomes invisible (disappear)
  2. Late prophase:
  • Formation of spindle fibres between two centrioles
  • Chromosomes are visible in the form of two sister chromatids
  • Breakdown of nuclear envelope

During meiosis, the events of prophase is divided into 5 subunits:

  1. Leptonema: chromosomes begin to condense and visible as thin thread like structure
  2. Zygonema: chromosome continue to condense and form synaptonemal complex through the process of synapsis
  3. Pachynema: crossing-over takes place between two homologous chromosomes to exchange genetic materials
  4. Diplonema: formation of chiasma i.e. crossing-over becomes visible at this stage
  5. Diakinesis: chromosomes become more condensed, so that formed tetrads are visible


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