Prophase

• what happens during early prophase?

  • the chromosomes condense, they coil, getting shorter and thicker and become visible as long thin threads-they become distinguishable as pairs of chromatids
  • centrioles are present in animal cells; the pairs separate and move to the opposite ends(poles) of the cell, organising a partner as they move-by the time they reach the poles, they are in pairs again
• what happens during late prophase?

  • protein microtubules form, radiating from each centriole, making the spindle - spindle fibres extend from pole to pole and from pole to the centromere of each chromosome
  • towards the end of prophase the nuclear envelope disintegrates and the nucleolus disappears
  • pairs of chromatids can clearly be seen lying free in the cytoplasm
• what is this a diagram of?

  prophase